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Academic Program At CEPT

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Academic Program At CEPT

For more details visit: https://cept.ac.in/

Buildings with low energy use are a social and economic imperative for India and other tropical regions that will see the largest growth in the next two decades. Energy use largely determines the environmental footprint of a building over its life span. Research, policy and practice are making building energy performance an area of intellectual and professional growth. Increasingly, a new kind of professional is needed in the building design or operations team to help save energy.

Within the M.Tech. program in Building Energy Performance students learn to:

  • Use state of the art tools to conduct simulations and assess building energy performance.
  • Tackle complex technical problems and participate in a multidisciplinary environment.
  • Contribute to and influence the design of energy-efficient buildings, while considering the architecture and environment, occupants’ behaviour, their health and comfort.

CEPT University is recognized internationally for high quality research and practical experience in energy efficiency and net-zero energy buildings. Our focus on design and management of human habitat provides a supportive eco-system for the building energy performance program. Our faculty consists of industry experts, experienced practitioners and researchers who have a solution oriented approach. We have a world-class research facility that houses the latest equipment for testing and measuring thermal and luminous effects in buildings.

India and other tropical regions are experiencing an unprecedented economic growth and environmental concerns. Regulations, green building rating systems, and owners’ preferences have created a demand for building energy professionals. With a focus on warm climate, the graduates of this program are attractive candidates for job markets in India, South-east Asia and the Middle-east, and for research careers in Europe and North America. They will work in energy consulting firms, building design teams, with building owners and government agencies, taking a leading role for pursuing energy efficiency with a whole-building perspective.

For more details visit: https://cept.ac.in/

Buildings with low energy use are a social and economic imperative for India and other tropical regions that will see the largest growth in the next two decades. Energy use largely determines the environmental footprint of a building over its life span. Research, policy and practice are making building energy performance an area of intellectual and professional growth. Increasingly, a new kind of professional is needed in the building design or operations team to help save energy.

Within the M.Tech. program in Building Energy Performance students learn to:

  • Use state of the art tools to conduct simulations and assess building energy performance.
  • Tackle complex technical problems and participate in a multidisciplinary environment.
  • Contribute to and influence the design of energy-efficient buildings, while considering the architecture and environment, occupants’ behaviour, their health and comfort.

CEPT University is recognized internationally for high quality research and practical experience in energy efficiency and net-zero energy buildings. Our focus on design and management of human habitat provides a supportive eco-system for the building energy performance program. Our faculty consists of industry experts, experienced practitioners and researchers who have a solution oriented approach. We have a world-class research facility that houses the latest equipment for testing and measuring thermal and luminous effects in buildings.

India and other tropical regions are experiencing an unprecedented economic growth and environmental concerns. Regulations, green building rating systems, and owners’ preferences have created a demand for building energy professionals. With a focus on warm climate, the graduates of this program are attractive candidates for job markets in India, South-east Asia and the Middle-east, and for research careers in Europe and North America. They will work in energy consulting firms, building design teams, with building owners and government agencies, taking a leading role for pursuing energy efficiency with a whole-building perspective.

Building Energy Simulation for Optimal Control of Water-Cooled Chiller in Office Building

Ch Yesaswini, Samit Bhowmick
Abstract: Building HVAC systems can consume more than 20% electrical energy when compared to the design intent which is mainly due to equipment performance degradation, equipment failures, or detrimental interactions among subsystems. Several buildings are today being monitored and the large amount of data related to energy consumption is collected. To manage energy efficiency, model-based energy management at operational stages is suggested. The study presents an approach to calibrate and optimize the energy performance of a Heating, Ventilation and Air Conditioning (HVAC) system. Further the proposed study adopts the parametric methods in controls of HVAC system to influence the annual cooling energy consumption of the building and enhance its operational cost savings. The type of HVAC system adopted in this study is a water-cooled electric chiller with a capacity of 425TR for an office building located in Bangalore. Calibration involves iterative improvements to align the model outputs with that of the measured data of an existing building. The calibrated models aid in comprehending the building operation as well as optimizing the performance. Therefore, the study focuses to provide the lessons learned and recommends the best practices for effective calibration of the water-cooled chiller of an office building. The chiller size is of capacity 425TR (x 4 units) with annual cooling energy consumption of 260000 kWh. Post carrying out 30 iterations in the model the resulted CVRMSE is 5% and NMBE of 1%. This calibrated model is further taken to find the optimized chiller outlet water temperature on the evaporator side. It is found that by an increase in outlet water temperature to 9°C, the energy savings is 1.2%.

Evaluating the role of Adaptive, Non-adaptive, and Contextual factors in determining the AC usage behavior in Indian households (2021)

Ayushi Mishra, Shalu Agrawal, Rajan Rawal
Abstract: With unprecedented urbanization, India is expected to see a steep rise in the residential cooling demand. Despite the alarming projection, the ‘what, why, and how’ of cooling behavior remains fairly less explored in the Indian context. As stressed upon by IEA Anne 53, variation in behavior often leads to a mismatch in the actual and predicted energy performance of the buildings leading to greater issues such as higher return on investment and unachieved energy targets. Behavioral uncertainty leading to unreasonable peak demand has become one of the major challenges for the government and distribution companies in the tropical regions.Detailed observations and understanding of the behavioral variables can lead to a tailored policy approach responding to different household groups. While there have been several instruments identified to understand occupant behavior, often they have been reported to be too impractical and cost-ineffective by the past researchers. Amidst the unfortunate scenario and restrictions, the introduction of smart metering systems worldwide is proving to be a boon. The availability of real-time electrical data communication has led to a lot of interesting insights useful to energy policymakers in the developed countries. The launch of the Smart Meter National Programme and its aim of replacing 25 crore conventional meters with smart meters will lead to a huge amount of data generation in India as well. With such upcoming technology, it becomes vital for the community to explore the possibilities and insights that can be generated through the data leading to better energy security in India. The study evaluated the cooling behavior by using machine learning and statistical analysis on the data collected through the smart meters installed in 34 households of Mathura and Bareily. It raises a set of fundamental questions around the parameters that determine the AC usage behavior in Indian households. Based on the commonalities 3 prominent groups of households were found i.e (1) Active users (2) Average users (3) Conscious users. Their usage characteristics and the possible strategies (Behaviour, building, or equipment level) has also been discussed as a part of this study.

Upgrading RETV as a retrofit solution through uncertainty analysis and its economic assessment on existing residential units across India (2021)

Urvi Shah, Rashmin Damle
Abstract: Building industry is one of the largest energy consumer and thus has a high potential of saving the energy consumption as well. In the year 2018, the building sector in India consumed over 30% of the total electricity consumed in the country annually and ranks second followed by industrial sector as the largest emitter of greenhouse gases. Out of the total electricity consumed in the building sector, about 75% is used in residential buildings. The gross electricity consumption in residential buildings has been rising sharply over the years. Therefore, there is an urgent need to control the residential energy consumption. Residential buildings have large exposed façade area to built-up area ratio, resulting in the space cooling loads dominated by heat gains from the envelope. Thus, an improvement in the building envelope using energy-efficient measures can yield the desired performance. Eco Niwas Samhita is a recent energy conservation code for residential buildings which evaluates the net heat gain from the building envelope with the help of RETV metric. The available literature indicates that given the large existing residential building stock and significant potential to reduce the space cooling requirements, retrofitting of existing residences needs a focus attention. Therefore, the thesis focuses on upgrading the RETV of existing residential units across India.

The scope of the work is divided into two parts: 1) Data collection; 2) Simulation-based analysis. The first part focusses on onsite data collection such as wall and window area, construction assembly details, depth of overhangs, orientation of the residence and electricity bill. A total of 30 2BHK residential units with AC’s installed were surveyed. The data collected from the survey formed the base of input parameters for the second part of the study. The latter part focuses on upgrading the RETV through uncertainty analysis and proposing energy conservation measures. The feasibility of the measure is checked based on RETV reduction and payback period. Input parameters used in parametric analysis are orientation, U value of wall, SHGC of glass, U value of glass, U value of window frame, overhang depth and wall to window area ratio. Four cities per climate zone are selected to upgrade the RETV with a total of 512 simulation cases each for each city. The energy conservation measures are classified into three categories as low, medium and high strategies based on the reduction in consumption and payback period. The feasibility criteria look up table will guide the owners to invest in the proposed strategies based on the existing available data of energy consumption, orientation of the residence, overhang depth and wall to window area ratio

Study of Natural Ventilation Potential and its Influence on Indoor Air Quality of the Bedroom’s Microenvironment, Gwalior, India (2021)

Akshat Gupta, Swati Puchalapalli
Abstract: Natural ventilation (NV) has the potential to influence indoor air quality (IAQ) in built microenvironments. Not only NV is an important energy-saving factor, but from a health, wellness, and comfort perspective, it is crucial. The Residential Energy Conservation Building Code (BEE, 2018) identifies it as one of the potential passive strategies to reduce energy use, by allowing NV in favourable outdoor conditions. However, its full potential couldn’t be utilized due to unavoidable constraints of severe outdoor air pollution in many urban environments. Several studies have shown that a higher air exchange rate (ACH) can be an energy-efficient measure to improve IAQ. This study attempts to monitor IAQ for similar events in a heavily polluted environment and correlate the result with the measured ACH higher to understand the indoor/outdoor (I/O) air pollution ratio. Dilution of the indoor pollutant is the only method to enhance the IAQ in the naturally ventilated spaces, by providing the required outdoor fresh air. However, the impact of such dilution when the outside is polluted is an understudied area of research. This study to curb the identified gap was carried out in the polluted urban environment of Gwalior, Central India, during the winter months of December 2020 to March 2021.A two-part methodology was developed for conducting the study, in the first part, the ACH was measured on selected 30 naturally ventilated bedrooms to find out if they meet the ventilation standards. In the second part of the study, the primary sources of air contaminants in the bedroom micro-environment were monitored indoors and outdoors. The result of the effect of the independent variables such as window type, number of windows, location of the opening, floor height, mesh, surrounding built-up density, etc. was compared with the ACH and IAQ to analyze the indoor/outdoor ratio.The ACH results presented a weak correlation between the measured data and the code recommendation of 12.5% of the openable window to floor area ratio. Only one bedroom was found to meet WFRop's recommendation, but 16 bedrooms were found to meet the standard for ventilation requirements. This realized that other parameters also have an impact on ventilation requirements. Further results indicated that infiltration and cooking are the major cause of indoor air pollution with 57% and 27% respectively. This indicated that even with a closed window, levels of pollution inside may be identical to those outside. Other results showed that the bedroom with a higher ACH was found to have a lower indoor to outdoor pollution ratio, However, these bedrooms also had more polluted hours because of infiltration (Outdoor pollution). The study focused on to what extent natural ventilation might be an energy-saving measure to improve indoor air quality during the episode of outdoor pollution and the conclusion and recommendations were made concerning design characteristics to improve NV and IAQ.

Developing and Calibrating a Cost-Effective Method to Determine the Window-to-Wall Ratio and Air-Conditioning Status of Existing Buildings (2021)

Abraham Philip, Shaily Gandhi, Rajan Rawal
Abstract: The air-conditioning system is one of the major consumers of electricity in an urban context with the window/glazing in the building being the weakest elements in the envelope susceptible to heat ingress. In India, the HVAC system comprises 40% of the building's energy consumption. Thus, it is crucial to have a detailed building characteristic dataset to develop a robust Urban Building Energy Model (UBEM) to estimate the annual energy demand and consumption profile. UBEM can be used to evaluate retrofit or design options and study the impact of climate change or other extreme environmental events. Generally, the process of data collection for the same is through construction documents or a large-scale field survey. This process will require an unreasonably high human effort and time which will impact its scalability and replicability.

In this study, a method is proposed to estimate the window to wall ratio (WWR) and air-conditioning status of a building from its ground-view façade imagery. The input image dataset includes visible and thermal IR images of the same perspective, captured using a thermal camera. The method consists of an algorithm that is divided into 3 segments. The first, consisting of an object detection classifier using Faster R-CNN, a deep neural network, is used for building and window detection from the visible input images. The second segment calculates the area of the bounding boxes of the objects which are used to estimate the window-to-wall ratio. The third segment super-imposes the bounding coordinates onto the thermal image to extract the pixel values which represent the surface temperature of the window and external wall region. When the difference between the window and the wall regions is greater than 7oC, it is regarded as air-conditioned. For object detection classifier with a precision of 57% (based on the training dataset used) estimates the WWR with a variation of 40%.

The algorithm developed through this thesis can help develop a rich dataset to generate an urban building energy model with LoD3 (Level of Detail). This mode of data collection has better scalability and replicability to make it both a time and cost-effective method to be adopted in developing the building stock model for energy modeling. This resultant Urban Building Energy Model can simulate the energy performance of the buildings in the urban environment to provide quantitative and qualitative insights for the stakeholder to provide informed decisions.

A case study on thermal performance in residences with laterite stone and rammed earth materials in warm and humid climate. (2021)

Uma P, Rashmin Damle
Abstract: The building envelope is a barrier to ambient conditions and its composition influence heat transfer. Walls and roof form a major portion of the building envelope hence, an envelope with high thermal performance acts as an energy conservation measure, providing indoor thermal comfort. A Laterite and rammed earth residence were considered as the study subjects and the thermal performance of the walls with its influence on the indoor conditions were analysed. The study was spanned over a period of 3.5 months where surface temperatures of the walls oriented to different directions and indoor conditions of its adjoining spaces were monitored. The laterite stone walls showed a mean inner surface temperature of 29.3°C to 30°C on all the walls oriented along different directions. The indoor air temperature was observed to have a mean of 30.8°C whereas the indoor mean radiant temperature, a measure of the radiant impact of the surfaces had a mean of 31.3°C. In the rammed earth residence, the mean inner surface temperature was least for north wall at 27.3°C and highest for south wall at 28.4°C. The mean outer surface temperature ranged from 29.4°C on the north wall to 34.1°C on the south wall. The large difference between outer surface temperature and inner surface temperature of the rammed earth wall can be attributed to the high thermal conductivity of the walling material. The indoor air temperature was observed to have a mean of 30.7°C whereas the indoor mean radiant temperature, a measure of the radiant impact of the surfaces had a mean of 30.2°C. The lower mean radiant temperature compared to the air temperature showed that the walls provide a cooling effect for the indoor spaces. As the building designs are not identical, an attempt to analyse spaces with similar exposure and adjacency was done have a preliminary understanding of the difference in the two materials. Comparing the distribution pattern of the surface temperatures of the east wall showed that 45% of inner surface temperature for rammed earth and 97% of inner surface temperature for laterite stone were more than 28°C. Hence rammed earth wall due to its thermal properties has an overall 2°C lower surface temperature compared to laterite stone wall. Comparing the indoor air temperature and relative humidity levels, it was observed that 76% of the data for rammed earth observed a temperature less than 31°C while the relative humidity was less than 68%. The thermal simulation study found that with the use of rammed earth, cooling load for a space can reduce by 10%. Additionally, the rammed earth wall had a lower time lag of 5 hours compared to laterite stone of 7 hours which showed that the walls cool faster due to its higher thermal conductivity, which helps naturally ventilated buildings to lose heat faster and cool leading to higher comfort levels.

Exploring the effects of urban air pollution and dust on loss in daylight transmittance of glazing (2021)

Stuti Goyal, Minu Agarwal
Abstract: A field study of windows was carried out for six institutional and hospitality buildings located in Delhi and Ahmedabad to assess the impact of dust on daylight transmittance of glazing. Vertical illuminance measurements were taken using a lux meter to calculate the relative percentage loss in visible light transmittance (VLT) due to dust on glazing. The measurements were carried out under overcast conditions for stabilized illuminance readings. The VLT loss was observed to be between 2% - 11% for over 75% of the 108 windows that were studied. Factors affecting the dust deposition included (but were not limited to) shading type and length, exposure to indoor or outdoor dust, indoor room conditioning and frequency of cleaning. The range of light transmittance loss was found to be 0.8% to 29.69% while the mean was recorded as 8.72%.

To analyze the worst-case scenario and the extent of soiling that a glass surface can undergo, a glass sample was soiled in laboratory by repeatedly spraying (aqueous dust solution) and drying the sample till dust saturation was reached. A relative loss of 55% in glass VLT was observed after 30 consecutive soiling cycles, beyond which soiling the glass further did not yield considerable difference in its light transmittance. A soiling saturation curve was derived out of this experiment to inform the inputs in daylight simulations carried out in LightStanza.

Annual daylight simulations for the Academic block in Indian Institute of Management, Ahmedabad were performed which showed a maximum relative decrease of 62.8% in Useful Daylight Illuminance (UDI) due to VLT deterioration because of dust deposition on windows. A 139% increase in average percentage of hours falling under insufficient illumination (<100 lux) was observed when the windows were dirty. The magnitude of change in horizontal illuminance levels was found to be perceptible to human eyes.

Simulations were carried out to assess the impact of dusty windows on lighting energy of two typical rooms in the building. The rooms were provided with manual switching controls and automatic daylight dimming controls to observe the impact of daylight dimming and regular cleaning on lighting energy consumption. The absolute effect on annual energy consumption was observed to be insignificantly low (lowered by ≈120 kWh/ room) when considered for its impact at the building level.

Understanding active shading usage behaviour of external movable shades in residential buildings of Ahmedabad (2021)

Snowy Christophel S, Minu Agarwal
Abstract: In the last 10 years, 43% increase has been observed in heat wave incidents in the city of Ahmedabad located in the hot and dry climatic region in India. With average summer maximum daytime temperature of 41⁰C and increased frequency of extreme weather conditions, occupant controlled passive design measures such as external movable shading devices are an important strategy for integrating resilience into buildings to provide indoor comfort.

This study is focused on understanding the occupant behavior in operating external movable shades control installed in balconies of residential buildings in Ahmedabad, India. External balcony shades influence direct solar gains incident on the balconies, access to daylight and views in the indoor spaces, air movement in the balconies and adjacent spaces. Occupant behaviour was observed in terms of frequency of shade deployment and frequency in change of shade position in response to outdoor environmental conditions. From the frequency of shade movement, the proportion of occupant behaviour has been further categorized as: passive, active and non-users.

Passive users are defined as occupants moving their shades occasionally i.e. less than four times for a defined study period whereas Active users move their shade frequently at a rate more than four times throughout the study period. Non-users do not move their shades even once during the entire study period. In this study, the factors influencing the active and passive users are considered to understand the strongest correlation variable with the average shade occlusion.

The data collection method involved recording and observing the potential change in usage of shades with environmental conditions over a period of two months in the Spring of 2021. Shade movements were recorded three times a day for 166 balconies (total number of recorded positions = 4,560).

The results from the above-mentioned observations indicate that the occupant behaviour pattern is influenced by a variety of variables such as time of a day, orientation, solar radiation, sunshine duration hours and sky type. From this study 21% of occupants were identified as passive users, 14% as active users and 65% were found to be non-users. The results of this study can be used to access the effectiveness of manually operated external shading devices located in balconies as a passive resilience measure in buildings.

Evaluating the effect of ceiling diffusers on airflow patterns in an office space to achieve effective air distribution. (2021)

Sejal Shanbhag, Rashmin Damle
Abstract: Air is the primary carrier of contaminants/pollutants in an indoor space and a governing parameter in achieving an acceptable indoor air quality. People spend more than 90% of their daily life indoors. Hence, it becomes inevitable to maintain the indoor spaces clean and healthy, which profoundly affects the productivity and safety of the people in the space. The testament from various researchers, research organizations, and civic health bodies of various nations regarding air being the primary carrier of the contaminants demands a need to investigate the transmission impact and measures that can reduce these effects. The ASHRAE building readiness guide advises an increase in outdoor air ventilation and enhanced filtration as solutions at the system level. The measures suggested address the contaminant transmission impact by varying the outdoor air fractions and providing effective filtration systems. These can lead to a rise in energy consumption or changes to the system size, having monetary and environmental impacts.

Centers for Disease Control and Prevention describes controlling exposures as a fundamental method to protect people indoors. Previous research studies have shown that improving ventilation effectiveness enhances indoor air quality without necessarily increasing air change rates. However, these studies are limited to clean rooms and laboratories, which function at higher air change rates. This research study investigates air distribution systems’ ability for effective air distribution in the occupied zone considering a contaminant source (occupant-generated) in the room.

Ceiling diffusers have a significant impact on indoor air temperature and air velocity. This study focuses on the predominant air distribution systems of mixing ventilation used in office spaces in India, with mainly three types of ceiling diffusers, i.e., square, round, and vortex. This study aims to understand the impact of the ceiling diffuser types, their relative location to occupants on the airflow patterns, and the quick removal of airborne contaminants. The fluid flows are analyzed by computational fluid dynamics (CFD), which uses numerical analyses and structured data using the finite volume method to solve the room's air distribution. The present study considers tracer gas as internally occupant-generated pollutants. Multi-objective optimization is performed for all the parametric combinations using modeFRONTIER, which uses a machine-learning methodology to mimic the CFD solver and reduce the computational time. The workflow tests with various optimization algorithms and produces local and global optimum results.

The assessment of air distribution due to the diffuser type and its location is carried out by evaluating air distribution performance index (ADPI), air change effectiveness (ACE), and ventilation effectiveness (VE), gaining insights into desired airflow patterns and control method for occupant generated contaminants. The outcome of this study will suggest an optimum diffuser design and its location for the office space. This research study will further help identify retrofitting measures that can be energy-efficient, propagate a measure for maintaining healthy office spaces, and be involved as a design intervention at HVAC system design stages.

Operational, economic, and environmental impact assessment of existing DX-split systems in Hot and Dry climate (2021)

Sammit Pancholi, Yash Shukla
Abstract: The study is conducted at Centre for Environmental Planning and Technology (CEPT) University, and focuses on split air-conditioning systems throughout the entire university campus, as it is the most predominant system amongst all HVAC systems installed. The global split air conditioning systems market is expected to grow at a noteworthy Compound Annual Growth Rate (CAGR) of around 4.3% and reach around US$ 178 billion by 2026. Rising global temperatures coupled with population growth and an increase in disposable income, make India and other southeast Asian countries vulnerable to higher demand for air-conditioning systems. Bureau of Energy Efficiency (BEE) launched a standard and labeling program for RACs in 2007 and revised the energy efficiency norms periodically, resulting in overall efficiency improvement to the extent of 36%. However, there is further potential to improve the efficiency of RACs to meet the rising energy demand, and installing these systems while replacing existing systems is the challenge. Along with strong policies supporting this action, it requires more case studies proving the same to be beneficial. For that purpose, the following study is being conducted, taking into account various parameters which can affect the performance of a split–air conditioner, and along with it the cost-benefit that is derived not just by upgrading to more efficient systems but how better maintenance can prove to be beneficial. It also considers their reduced impact on the environment considering the use of less harmful or 'green' refrigerants, and reduced power consumption. The study focuses on operational performance, climate impact, and economic assessment of 135 split-air conditioning units at the CEPT University Campus, ranging from 1.4 TR to 2.1 TR. It also considers the climate impact due to the different measured power consumption, air-flow, filter condition, type of refrigerant used, etc. The key findings show that a majority (71 units) are of 1.5 TR capacity. And 94 units use R22 as a refrigerant, which will eventually be phased out. This forms a strong base to consider a replacement scenario, with strong climate and environmental benefits. The study finds that the measured performance reduces by an average of 16% for all units. The payback period when considering super-efficient air-conditioners with an ISEER rating of 5.6, using R32 refrigerant, was less than 3 years, while the climate impact is reduced by 70% and 80% when compared to R22 and R410A respectively. Replacing all the existing units with super-efficient air-conditioners is a step in the direction of reducing the climate impact due to the inefficient performing air-conditioners.

Evaluating the impact of future climate change on a present net-zero energy building; case of CARBSE building. (2021)

Roota Trivedi, Minu Agarwal, Daniel Zepeda Rivas
Abstract: Human activities are causing climate change. Greenhouse gas emissions are specifically the leading cause of the rapidly changing climate. Net Zero Energy buildings are one of the solutions to cater climate change problem in the construction sector. These net-zero energy buildings are meant to perform net-zero throughout their life span. Major building simulations are however for the net-zero energy buildings done using typical weather files. Typical weather files are being generated using historic weather data, which represent past years. As, the Indian context, life span of the building is expected to be 75 to 100 years, it is expected to perform net-zero throughout the lifespan from the building. Hence future weather files are important to be looked at. IPCC has developed the weather scenarios for future climate. Based on these weather scenarios future weather files can be generated. While designing such futuristic buildings, in the building simulation future weather data could be one of the focus points. CARBSE is a net-zero energy building at CEPT University, Ahmedabad. That same is considered as the case study as a part of this thesis work. The building has recorded all the energy usage data from the year 2016 to 2019 for evaluation, as it is a living lab for building energy performance. This study starts with understanding and generation of future weather files. Secondly, comparing future weather files and typical files with the actual years for better understanding. Climate analysis and scope of passive strategies in future years are a major concern as the building uses such energy conservation measures to reduce cooling load. Building performance assessment and net-zero status check are done for the same weather years. If the building is not managing to maintain its status of net-zero, what are the reasons behind the same are looked at in detail? Refurbishment solutions for Envelope, HVAC systems and Renewables are proposed and evaluated by the cost as well. From all the above refurbishment solutions, a method can be developed to evaluate net-zero energy building according to owners’ perspective for energy and cost.

Hygrothermal performance of lime and cement plaster (2021)

Nikita Khatri, Rashmin Damle
Abstract: The energy requirement of a building is directly related to the thermophysical properties of the building envelope materials. Bioclimatic architecture and appropriate use of building materials can drastically reduce the energy requirement and improve the indoor environment. Hence, the practitioners are promoting building materials that are sustainable, vernacular and have lower embodied energy. Lime is one such sustainable material, receiving attention and is under the process of revival. The building envelopes plastered with lime have sustained through 700 decades and continue to withstand the dynamics of environmental conditions. A building envelope acts as an interface between the outdoor and indoor environments. Across a building envelope, heat transfer takes place by the virtue of temperature difference while moisture transfer takes place due to gradients of vapour pressure or relative humidity (RH). Heat and moisture transfer occur simultaneously and are dependent on the hygroscopic properties of the building materials. This coupled phenomenon (hygrothermal behavior) in materials can impact the energy consumption and thermal comfort of the building space.

Currently, cement plaster is the most commonly used for plastering building surfaces instead of the traditionally employed lime plaster. With this context, the objective of this study was to evaluate the hygrothermal performance of cement and lime plastered surfaces. To understand the behaviour of these materials, two test cells of 1m3 volume having similar geometry and construction were developed. The test cells were constructed in Jodhpur, India. The city experiences a hot and dry climate where the temperatures range between 45–50℃ in the months of May-July. Lime has been a vernacular material employed for plastering in the older settlements of the city and is believed to keep the indoor environment cool.

The performance of these two plasters was evaluated by carrying out both experimentation and simulation. The test cells were monitored for surface temperature, moisture content, indoor air temperature, RH and globe temperature. It was observed that the indoor temperature of the lime plastered cell was lesser by 3.1-5.2℃ as compared to the cement plastered test cell. The moisture buffering capacity of the hygroscopic lime was evident from the variation of indoor RH, surface RH and moisture content of the test cells. The variation of indoor RH in the lime plastered cell was in the range of 23-60% while the same for the cement plastered cell was 20-65%. Moreover, the plaster type also affected the thermal comfort parameters. After evaluating operative temperature with India Model for Adaptive Comfort (IMAC), it was observed that conditions in the lime plastered cell were 40% of the time more comfortable than cement plastered cell. Hygrothermal simulations carried out with the Effective Moisture Penetration Depth (EMPD) algorithm showed that the measured and predicted indoor air temperature and RH were in good agreement with a relative difference of 2-4%. Thus, the EMPD model could predict the hygrothermal behavior of the test cells. In view of the above, the application of lime plaster can significantly affect the indoor temperature and RH and can be employed as a sustainable measure for energy efficient buildings.

Carbon-based Performance Evaluation of a Net Zero Energy Building (NZEB) using a Life Cycle Approach: A Case Study (2021)

Mili Jain, Rajan Rawal
Abstract: Net-zero energy designs typically have incremental monetary costs due provision of elements like PV panels, efficient HVAC equipment, insulation, DGU windows etc. These materials and/or equipment translate to incremental embodied carbon as well. The annual performance evaluations do not consider this embodied carbon released before the use of the building. They also don’t consider the impact of deconstruction and disposal of the building. The annual savings of a building might not be able to compensate for these emissions. A net-zero energy status is thus, not sufficient to ensure savings in greenhouse emissions across the lifespan of a building.

The accounting of emissions can be done through a Life Cycle Analysis (LCA). The goal of conducting the LCA then is to quantify the amount of CO2 emissions that are to be extracted from the environment to reach an absolute zero carbon status. It opens possibilities of bridging the gap between net-zero energy and absolute-zero carbon for a net-zero energy building (NZEB) in India. This study looks at the quantification of the trade-off needed for an existing NZEB based on requirements of ISO 14040/44.

The data collection process requires spanning several reporting locations and published references. The consistency in data quality was achieved through the evaluation of data sources against indicators for type, age, geography and data units. The uncertainties in data and assumptions progress in the calculations and also affect the reliability of the results. The results of a Pareto analysis were used as a proxy for an uncertainty importance analysis. The uncertainty of the largest inputs was explicitly addressed to establish the accuracy of the inventory.

Once the trade-off is quantified, it enables the possibility of developing a business case to compensate for the emissions. The NZEB can target achieving a net-zero carbon status within a certain time. The gap between net-zero energy and net-zero carbon was calculated to be 2,619 tCO2e. The study results in an understanding of the sensitivities of a life cycle analysis towards the system boundary, data quality requirements and acceptable limits of uncertainty. The inventory developed for this study applies to any building constructed within Gujarat from 2012 to 2018. This can be used to scale up the research to create benchmarks and/or standards.

Assessing the Impact of Sizing Methods on the Performance of Radiant Cooling Systems (2021)

Het Modi, Yash Shukla
Abstract: The physics of heat transfer in a zone cooled with a radiant system differs from all air systems. In case of zone cooled with radiant system, heat is removed by both convection and radiation whereas in case of all air system heat is removed by convection only. Standard Cooling load calculation methods suggested by (ASHRAE, 2017a) standard considers overhead well mixed system and heat removal by convection only. In case of All air system, convective load instantaneously becomes cooling load, and the thermal mass of the zone first absorbs the radiative part of the load and later it is removed by convection to the zone air. Because of direct removal of some part of radiative load in case of radiant system, cooling load in case of radiant system is different from all air systems. Also, standard cooling load calculation methods consider a constant temperature setpoint for calculating cooling load which is not necessary for achieving thermal comfort. Standard cooling load calculation methods fail to identify this difference, and this has been identified by much literature. In this thesis, a survey of radiant system designers of 40-50 buildings was conducted to understand the current scenario of radiant system design in India. It was identified that most designers do not differentiate cooling load between radiant and all air system. Based on survey and literature study, 5 cooling load calculation methods were identified, and radiant system was designed using these methods. Assessment of radiant system for these 5 methods was carried out by simulations using DesignBuilder which uses EnergyPlus as simulation engine. A validated model from the literature study was selected for the analysis. EnergyPlus was used for simulations because it performs the heat balance for all the surfaces of the zone and conduction transfer function has been modified to include the heat sink/source within a surface and it can capture the transient behaviour of radiant system. The simulation results identified that the peak cooling rate in the radiant system was 46 – 68% higher than what was calculated using standard cooling load calculation methods. By designing the radiant system using iterative method using simulations, it was identified that up to 50% reduction in plant size was possible compared to standard design procedure.

Study on evaluating net-zero energy potential for an apartment building (2021)

GVS Raghavendra Rao, Swati Puchalapalli, Minu Agarwal
Abstract: India — the second-most populous (1.37 billion in 2019) nation of the world (International Monetary Fund, 2021) - is anticipated to have the biggest population in the world by the year 2030 (UN, 2019). Concurring to the 2011 census information, India’s number of households was 246 million with a population of 1.2 billion (GoI, 2017). Under the 2011 average household measure (4.9) suspicion, there will be 307 million households in 2030.The floor area of residential buildings in India is evaluated twofold (16.0 billion sq.m to 31.6 billion sq.m) and the residential energy consumption is assessed to trifold (246 TWh/y to 748 TWh/y) between 2017 and 2030, as per NITI Aayog (2015). This development of residential floor space, combined with an increment in electricity production, leads to critical energy demand within the up and coming decades. Hence the significance of creating energyefficiency techniques & building energy-efficient residential buildings in India is fundamental (Rajan Rawal, September 2014).The purpose of the study is to assess net-zero energy potential for a proposed apartment building, suggest effective energy conservative measures, and see the financial achievability of the same by reporting the payback period and internal rate of return (IRR). The study will cover the economic feasibility of each energy conservative measure and the potential of photovoltaics at present state of art technology to combinedly achieve potential net-zero residential building.The study is conducted for a proposed G+12 apartment building located in Sonipat, NCR. The plug load data to calculate equipment power density is gathered by conducting a survey. The study also includes a 14 days comparison of simulated and measured indoor temperature results for a test room, energy-saving potential for Eco-Niwas Samhita form building as usual case,and its internal rate of return.After applying three different identified internal profiles (low-mid-high consumption) the BAU case EUI is in the range of 92kWh/m2-year to 88kWh/m2-year. ECM's - IMAC MM 90% temp. setpoints, shading, NV, efficient envelope, efficient PTAC system were identified as energy conservative measures (ECM’s). After all ECM's were applied one upon another the EUI is in the range of 37kWh/m2-year to 31kWh/m2-year (66% reduction from BAU case). Which gives a payback period of 8 months.A 73kWp of rooftop PV is installed which offsets 26 kWh/m2-year EUI with a payback period of 2.1 years. The ENS compliance case with a low payback period is found and this case has the EUI range of 69kWh/m2-year to 72kWh/m2-year (19% reduction from BAU case) which payoff from day 01 when used AAC blocks.

Thermal comfort and Energy performance assessment for Faculty of Architecture building at CEPT post restoration (2021)

Archie Parakh, Rajan Rawal
Abstract: Improving the energy efficiency of buildings is a key towards climate change mitigation strategy. Application of this requires upgrading the existing stock, a subset of this are buildings with historic importance. The study presents the thermal comfort and energy performance potential of building retrofits being carried out at Faculty of Architecture (FA) building at CEPT University, Ahmedabad. It is a building of modern heritage and has unique place in the history of modern architecture in India. The building also influences architectural teaching pedagogy in India and abroad. FA building was designed by B.V. Doshi in the year 1968 and was categorized as Universal Cultural Heritage in October 2017. It is being conserved as per the guidelines accepted by The International Council for Monuments and Sites (ICOMOS) and International Committee for Documentation and Conservation of Buildings, Sites and Neighborhood of the Modern Movement (DOCOMOMO). The structure is being upgraded in accordance with modern needs for comfort and environmental requirement. Retrofit of the heritage building has been carried out not only to reduce the energy consumption of the building but also to preserve the building for future generations. The study starts off by comprehending the trade-off between the heritage status of the building and energy efficient strategies proposed that addresses to the concerns of thermal comfort and energy conservation to support its round the year occupation. Workflow and approach followed for developing FA building energy model includes documentation of construction assembly, internal gain parameters, schedules, and system level details. The study commences by recording the Illuminance levels measured in various studio spaces and Glare Analysis for students and faculty members. This followed by study of the impact of night flushing potential on energy consumption for space cooling. A zone level comfort analysis comparison for pre and post restoration scenarios. Addressing the issues of thermal comfort and energy efficient strategies, ensures a healthy and sustainable lifestyle of the building occupants. The outcome of the proposal is a developed methodology for evaluation of post restoration scenario of a heritage building in terms of visual and thermal comfort, in Indian context. Also, this study can be further referred to monitor the intent of strategies proposed with actual building operations results.

Evaluating the energy-saving potential through occupant interaction with external fenestration in residential buildings (2021)

Amanda Cassiana Santiago, Rajan Rawal
Abstract: Occupant's interaction with external fenestration can have a large impact on the indoor environment and energy consumption of buildings. The increase in India’s residential cooling demand gives rise to the need for gaining a better understanding of mixed-mode operations in residential buildings.

This study explores the non-thermal drivers that inhibit occupant interaction with external fenestration, this is divided into three stages. Stage1: User window operation survey that reached out to 150 occupants to identify the non-thermal drivers that prevented the opening of windows during favourable outdoor environment. Stage2a: A field mapping study in which 10 residences were studied for a period of 5 days. The parameters monitored were temperature, humidity, CO2 and window operation status. Stage2b: An experimental stage to determine the window status by finding the air change rate through the tracer gas experiment. The experiment analysed the CO2 decay curves with various opening percentages, these curves were cross-referenced with the occupant-generated CO2 data to define the window status. To ensure the window status was accurately achieved multiple considerations were taken to maintain the occupant’s privacy.

Stage3: Simulation, assisted in identifying the ideal period for which windows could be operated. This established the possible energy saving by analysing the comfort hours. The whole building simulation model was created in design-builder to simulate the data collected on-site. The window operation schedule was fed into the simulation model and simulated for two cases, case one’s windows operation schedule was based on the differential temperature variation algorithm and case two in which the schedule was derived from the field study. In the study conducted in residential households, it was found that 90% of its residences the fenestration operations were under the influence of non-thermal drivers. This resulted in a 20% reduction in comfort hours.

Effect of Relative humidity on Adaptive thermal comfort (2021)

Akshay Garg, Rajan Rawal
Abstract: The design of active and passive techniques to manage the thermal comfort of the building occupants depends on the indoor design conditions (Temperature and RH). To recommend these indoor design conditions in Indian context, practitioners refer to standards like the NBC (National Building Code of India, 2016) which specify these conditions based on the building operation type (NV, MM and AC). However, the code does so by use of Indian Model of Adaptive Comfort which only specifies the Neutral Operative temperatures but does not specify the corresponding RH ranges for which it shall be applicable. This is so because it is an empirical model, and the RH data is built-in when it is derived. The specification of the same shall help the researchers and practitioners in applying the RH limits to the indoor comfort conditions specified for the spaces studied or designed. The Objective of the research was to include the RH signal into the IMAC thermal comfort equations. This was done by studying the open source published thermal comfort survey data (ASHRAE RP 884) through statistical methods like Griffiths Constant Method and Python based machine learning algorithms. The study resulted in definition of sensitivity of thermal sensation vote on change in indoor temperature in specific RH ranges and comparison of Neutral temperature so arrived with that predicted by IMAC model for all Naturally ventilated and Mixed Mode buildings. The study also resulted in specifying an updated prediction model for NV buildings with an RH range of 40 to 75 %. . This study shall apply to Indian conditions as the data utilized for the study shall be derived from the thermal comfort studies carried out in India.

Impact of mold growth on the Indoor Air Quality and Occupant Comfort (2020)

Vismaya Paralkar, Rashmin Damle
Abstract: Lime plaster is one of the key sustainable building materials which is also effective as a passive cooling strategy. It is well known for its moisture buffering capabilities. In this work, the hygrothermal performance of lime plaster is observed through simulations and surveys. Surveys are carried out for 45 traditional buildings of Ahmedabad in India with measurements of ambient variables, such as temperature, relative humidity, wall moisture content, etc. In hygroscopic materials such as lime plaster, realistic conditions like mold growth cannot be predicted through simulations. The surveys carried out are the best examples to understand the circumstances of mold growth. And an attempt is made to use these readings and observations to predict the phenomena of mold growth in a space while conducting simulations. To understand this, an experiment is carried out where similar samples of lime plaster are exposed to different Relative Humidity from 75% to 97%. This information can be then correlated with the surface relative humidity plotted through simulations. Moreover, the Relative Humidity at which the mold growth initiates in a lime plaster can be derived. Using a combined approach of simulation, survey, and experiment it was possible to predict the mold risk of the space.

Spatial & temporal thermal maps (2020)

Vardan Soi, Swati Puchalapalli, Rashmin Damle
Abstract: This paper presents a methodology to calculate and plot operative temperature (Top) for naturally ventilated (NV) spaces at multiple points in a thermal zone both spatially and temporally. The proposed methodology calculates 3 environmental variables (air temperature, mean radiant temperature (solar adjusted) & air velocity) which affects comfort for NV spaces and bisects the workflow.
1. Thermal simulation: To obtain air temperature and surface temperatures to calculate mean radiant temperature.
2. Computational Fluid Dynamics (CFD): To obtain air velocity distribution.
Further, data from CFD & thermal Simulation is amalgamated and integrated with other calculation variables such as view factor & effective radiant field (ERF) to derive Tair, Tmrt & Air velocity (Vair). The weather data is binned for wind direction to optimize the number of CFD runs. The proposed method limits itself to iso-thermal airflow and hence accounts only for wind assisted ventilation. Top across thermal zone is calculated for grid points to generate point-in-time thermal plots. Further, Top across all the data points in space will be translated into a spatiotemporal representation for a given set of thermal comfort acceptability criteria which will indicate the percentage of time a grid point meets the comfort condition.

OTTV a method of evaluating thermal performance of residential buildings (2020)

Utkarsh Mathur, Rashmin Damle
Abstract: A steep growth in the residential sector is expected as per the literature survey. Eco Niwas Samhita is a residential energy conservation building code which estimates the heat gain from building envelopes. In the available literature, nothing could be found regarding heat gain due to infiltration. Therefore, the thesis focuses on estimating the effect of infiltration rate on RETV. The study has two aspects, first being surveying 20 air-conditioned apartments and other being simulating 9216 parametric cases. It was observed that only 3 out of 20 residential apartments were under the RETV limit of 15W/m2. The blower door test suggested that the infiltration rate varies from 0.53ACH to 1.63 ACH. It was observed that the average infiltration rate is 0.74 ACH for aluminium sliding windows and 1.35 ACH for the wooden casement windows. The sensitivity analysis shows that the heat gain from infiltration can vary from 5% to 33% of the overall envelope heat gains. The Parametric analysis conveys that the heat gains from infiltration are as significant as that of walls. Lastly, infiltration coefficients are proposed for the revised RETV equation. The derived infiltration coefficients are 5.46, 4.22 and 3.53 for Hot-dry, Composite and warm-humid climate respectively.

Tree Shading Factor as input for thermal model through hemispherical photography (2020)

Suyashi Srivastava, Swati Puchalapalli, Marshal Maskarenj
Abstract: Solar irradiation has a huge impact on building energy consumption due to solar heat gains through the building envelope. Considering trees as exterior obstructions in initial calculation would optimise building energy efficiency. The challenge lies with the limited research on individual tree shade characteristics from a building modeling perspective. Therefore, a simplified methodology that would consider tree shade factors sans geometry without compromising on data accuracy for detailed energy estimation in various simulation engines is required. Site measured data through hemispherical photography and simulated results from Rhino honeybee and grasshopper are calculated in the workbook and presented as a Shading factor (SHF) schedule. Shading factor (SHF) is a possible solution to the above-mentioned challenge. It is defined as a fractional reduction in irradiation received over a building element due to tree shading. It is determined by finding canopy ‘Void ratio’ or ‘Transmissivity’ based on field parameters like canopy area, canopy density, tree species, tree location and orientation with respect to building element. Presently, no such study to incorporate native Indian trees as a passive measure in simulation engines is available. Therefore, this research study aims to propose a simplified methodology that includes factors such that it is recognized by various engines to ease the complex simulation process and reduce computational power.

Evaluation of Tubular Daylight Devices using Single patch Sky simulator (2020)

Sreejith Jayaram, Marshal Maskarenj
Abstract: Daylighting is a globally available free resource which can be harvested for proper utilization by the use of daylighting systems. Venetian Blind systems provide sun shading, view to the exterior and have the potential to increase daylight performance of interior spaces when used effectively. Studies have shown a 20-60% increase in visual comfort performance when these systems are used efficiently. This research introspects the concept of a traditional venetian blind system, redefines the venetian blind design by segmentally splitting the blinds based on the concept of the Field of View (FOV) of the human eye and evaluating the improved blind design by the means of advanced daylight simulations. In order to evaluate the improved system, a three-phase simulation method was used, and the illuminance results were extracted from the simulations. The illuminance data was then filtered on the basis of conditions provided and respective credit scores were given for every blind combination for every daylit hour of the year. The study then identified the strategies with high credit scores that could be used to operate the improved blind system. The results show that the improved blind design has a significant improvement of daylight performance over the BAU case. An annual increase of 73.1% useful daylight hours was observed. Though the results observed significant increase of daylight performance, it was important to evaluate the control algorithm for its cost function implications and predict how much energy may be consumed due to the continuous operation of the blinds. Recommendations to calculate the cost functions are attempted in this study. Further to this, a study was conducted to check if a This research also aimed to identify if any set of blind positions changing through the day would work consistently across the year, and to evaluate the relative merit of such a strategy. While the solstice strategies performed poorly, the equinox strategy worked well, with a reduction of annual performance by just 2%. This gives the operator an option to use a single daily strategy to cater to the entire year with a negligible visual performance compromise at a reduced cost function.

Integrated Parametric Design of Adaptive Facades (2020)

Siddarth Thoudam, Marshal Maskarenj
Abstract: Building envelopes are the key components that distinguish the exterior and interior environments. Dynamic façades and fenestrations are used as an important strategy for regulating the entry of daylight as well as solar radiation into the workspaces. Ensuring effective use of daylight is a challenge as it is often overused and sometimes underused in a built environment. Design and construction as well as operation of fenestrations thus have a direct effect on the availability of indoor daylight. Several studies have also shown that a good façade design will improve the psychological and physiological needs, thus increasing the necessity for research in this field. In order to check the effectiveness of an adaptive façade an origami-based design is chosen. To enhance the daylight performance using the Adaptive facade, a 3-Phase Daylight Simulation is carried out for both equinoxes and summer and winter solstice for one location. An annual simulation is also done for three locations with equal latitudinal difference for three cases. The daylight simulation was carried out through Rhino software using Grasshopper and Honeybee Plus plugins with a Radiance interface to explore the applicability of parametric design to improve daylight efficiency. An appropriate control strategy was developed for the adaptive façade. It was observed that the use of Adaptive facade improved the overall performance but was mainly effective till a certain distance from the façade and was ineffective after 4.5m distance for both equinoxes and summer and winter solstice. A latitude difference of around 5 to 13 degrees has no clear difference on the implementation of an adaptive façade of this design and may depend more on the climate of the region with different cloud cover.

Evaluating the scope of energy reduction by Pre-cooling the large volume occupant centric spaces using low energy cooling systems (2020)

Shubham Solanki, Adil SMH, Rashmin Damle
Abstract: India having a diverse climate, cannot accept a common and converging solution. In order to address the same, the study aims to reduce energy consumption by using a low energy cooling system. In order to understand the opportunity of change in cooling strategies, a thorough study of hybrid systems has been conducted in conjunction with the current scenario. The control program was designed using the EnergyPlus –energy management system. Sensor and actuator were used as an object to control the program in the model.Group simulation for all the 60 weather files were run and were segreagted into four climatic zones.The results show a reduction of 1.5-24% depending on their respective climate zone. The maximum reduction was recorded in Barmer and Jaisalmer with 24%. The minimum was recorded in Dibrugarh – 1.5%.With an advancement in the HVAC industry, the application of such systems can come into place. Observing the capability of the industry, the use of system along with sensors and actuators can be a way forward to the technology.

Study of occupant behavior to increase comfort and reduce energy bills in Affordable housing in Chennai (2020)

Niveditha P., Rajan Rawal
Abstract: The Pradhan Mantri Awas Yojana – Housing for All scheme aims at providing affordable houses to all eligible beneficiaries in India by 2022. Hence, with the increase in the number of households, the increase in energy demand is inevitable. Thus, there is a need to observe and analyse their energy usage along with their thermal comfort to address the growing demand. This study aims to identify the energy usage pattern and appliance penetration in affordable households along with the thermal comfort of the occupants. A field study was conducted in 20 affordable households in Chennai, which experiences a warm and humid climate. The study involved data collection like long-term monitoring of indoor air temperature, relative humidity, and energy consumption, background information of occupants, comfort assessment, behavior and energy usage, Right Here Right Now Thermal comfort surveys with questionnaires and instantaneous measurement using handheld instruments, building floor plan, observation of window and fan operations method, and the adaptive measures incorporated. The Residential Envelope Transmittance Value is calculated for all the houses and the relation between the building envelope and the indoor conditions is discussed. The study discusses the prevailing thermal comfort conditions in affordable households and the adaptive measures taken by the occupants to maintain their thermal comfort and their effect on energy consumption.

Developing solutions for Limiting Energy consumption of Buildings due to Socio-economic, Technological and Floor space evolutions (2020)

Nikhil Yaduvanshi, Rajan Rawal
Abstract: This study is conducted to project the increase in energy consumption due to the change in floor area of residential and commercial buildings and how the implementation of the Energy Conservation Building Code (ECBC 2017) can limit this increase in energy consumption. The site selected for this study is the CBD of the city of Ahmedabad. Bottom-up approach is employed, which is using urban scale energy modeling (USEM). The study requires future weather files for each year of the decade until 2050. IPCC scenarios of higher emissions RCP 8.5 were used for the weather forecasts. The other projection concerned is the increase in floor area, which was taken from the existing development plan for the city of Ahmedabad, which had allowed a maximum FSI of 5.4 defined in Gujarat DCR for the CBD. To consolidate the energy consumption projections, historical patterns are observed, and for aggressive and moderate growth scenarios. The results obtained show that there is a fivefold increase in energy consumption in 2050. The scenarios developed with the susceptive approach towards energy consumption helps in identifying the energy-saving potential for each of these cases, thus providing flexibility in understanding the effects of each of them when applied individually.

Enhancing daylighting for a Coaching Institute of 5 floors located in Solapur by giving retrofit solutions in consideration to life cycle cost analysis. (2020)

Mayuri Agrawal, Marshal Maskarenj, Poorva Keskar
Abstract: Today, the necessity of energy-efficient buildings is increasing continuously and along with it, understanding the electricity consumption in every aspect of these buildings has become important. Out of them, lighting systems covers up to 19% of the global electric energy consumption. Efficient use of daylight helps in reducing the consumption of electric lighting up to 20-40% which leads to energy conservation. If designing is carried out properly, attaining minimum glare factor, daylight can have advantages like reduced eye strain, falling stress levels, reduction of health problems and increase in productivity, which further leads to financial benefits to the organization as well as user satisfaction. The aim of this study is to analyse the daylight conditions and provide retrofit solutions to enhance daylight and reduce the energy cost of a 5 floored coaching institute, for higher secondary students located in Solapur city of Maharashtra state, India. The results of initial day lighting level simulations from LightStanza help to understand the scope of enhancement in this building. Thus, defining the spaces that need improvement. To analyse daylight conditions in these spaces, light levels are to be obtained/accumulated by measuring luminance through HDR imaging and in turn finding luminance-based illuminance. For this, a device is to be built which consists of a commercially available credit card sized computational device (Raspberry Pi) and a fisheye lens camera module. This HDR imaging device is then to be calibrated for various necessary correction factors. Studies show that this type of device provides an accuracy ranging from 5% - 20%. The illuminance levels from measured luminance are to be used to calibrate the simulation model in LightStanza and the generated results will be used for evaluation. After this evaluation, fenestrations need to be redesigned for enhancement of day lighting. These redesigned fenestrations along with other solutions will be implemented to one of the classrooms to measure the light levels to validate the study.

Rule based controls for liquid desiccant flow modulation (2020)

Mahesh Kumar, Yash Shukla
Abstract: India, as we know, is a rapidly developing country and is one of the most populated ones in this world. This is leading to a soaring rise in energy consumption and has shown a dramatic rise in the past decade. Of the massive energy needs of the country, energy for cooling and comfort is one of the most demanding sectors of consumption. Cooling is necessary as it directly implies to benefits of human development, health, well-being, and economic development (Agency, 2018; Angrisani, Roselli, & Sasso, 2013). India has projected growth in cooling demand of up to 2.2 times within the next 15 years (Ozone Cell, 2019). This demand is cooling needs to be addressed sensitively majorly because of the equally growing energy crisis as well as the weighted contribution of global warming and ozone depletion due to conventional cooling methods. Therefore, the right approach to satisfy this cooling demand of the country is to develop cooling technology with reduced energy consumption and reduced carbon emissions.

All buildings will have both latent and sensible loads. In conventional HVAC practice, the latent loads are very inefficiently treated. This results in a drastic increase in the overall energy consumption of the building. Considering the increasing annual carbon emission of 2% globally, the best way to treat these latent loads of the building is through non-refrigerant based methods. The solid desiccant technology has proven to be an impactful non-refrigerant based cooling technology that could help to efficiently cater to the latent loads of a building. This technology is a great and efficient addition/ replacement to conventional systems. But these systems are exhaustive and complex to set up and maintain. This has resulted in this technology to not be able to expand and flourish in terms of widespread utility even with its efficient benefits. Therefore, the thesis aims to make the solid desiccant system more market feasible by improving the operational efficiency of the system through developing sophisticated rule-based control algorithms. This work aims to impact the reduction of consumption as well as the improvement of the supply efficiency/ accuracy of the system.

The project is divided into 3 stages. The first stage is the modeling and simulation of the solid desiccant wheel under the EnergyPlus platform. The second stage is the derivation of the rule-based control algorithms from the physics-based first principal equations of a solid desiccant wheel. The final stage involves the implementation of these control algorithms into the EnergyPlus model through the inbuilt Energy Management System (EMS) and extract and analyze results.

There have been 3 cases created to compare the results of simulations. The first case being a conventional DX cooling coil AHU system attached to a single zone. The second case is a hybrid system of desiccant wheel + DX cooling coil with simple ON/OFF control logic (this is the most widespread control logic used for solid desiccant system). The third case is the desiccant wheel + DX cooling coil with the proposed control algorithm. The proposed control algorithms for the desiccant wheel system modulates 2 variables in the system. The two variables are the heater setpoint temperature for the regeneration side of the wheel and the mass flow rate of the balanced flow desiccant wheel for the process and regeneration side of the system.

The desiccant wheel + DX cooling coil hybrid ON/OFF system in comparison to a conventional DX coil system. The hybrid system saves up to 22.21 % of annual electricity consumption overall. The hybrid system also reduces the cooling coil size from 1.38TR to 1.26TR. Further, the developed control logic is implemented to the desiccant hybrid system and comparison is made. The desiccant hybrid system with the applied control logic saves up to -13.2% annual electricity consumption compared with the ON/OFF control system model. The cooling coil design size of the system is reduced from 1.26TR to 0.86TR.

Study of Ventilation types in Hospital critical Environments and their impact on Energy Savings.(2020)

Krutika Sharma, Aalok Deshmukh
Abstract: With round- the-clock use and high occupancy in hospitals, the indoor air quality of the critical areas along with the energy usage of the space (mechanical systems) to keep it running, is the most impacted. As the patient’s health is the most critical factor in an ICU, the need for maintaining a good indoor quality is of paramount importance. The ventilation system provided and outdoor ambient conditions directly impact the indoor air quality in the space. HVAC systems play an important role on the infection risk in critical and sterile spaces. ASHRAE Standard for prescriptive “ventilation rate procedure” and its performance-based approach of “indoor air quality procedure” (IAQP) help determine minimum Ventilation rates (VR) based on objectively evaluated indoor air quality (IAQ). The first primary goal of this study was to determine, in the intensive care unit (ICU, the adequacy of ventilation rates (through the existing HVAC system) observed through measurements in providing the level of IAQ specified through the IAQP process. The second goal was to evaluate whether VRs implemented experimentally would achieve adequate IAQ, assessed objectively & subjectively (although subjectively is for the future scope of this study) Mass balance models were employed to calculate indoor contaminant generation rate within the ICU. Using this model, the typical outdoor air contaminant concentrations, to calculate the ventilation rates that would maintain indoor contaminant concentrations below the selected REL. These VRs were compared to the measured and prescribed VRs in ASHRAE 170. An experiment is performed to check if by applying the IAQP to allow lower VRs in the considered zone, energy savings are possible whilst still maintaining acceptable indoor air quality. Based on the findings from applying the IAQP calculations and through an experimental performance optimization in the ICU, recommendations are made with regards to energy saving potential.

Impact of stacking outdoor AC Units on Building Energy Consumption (2020)

Krishna Patel, Rajan Rawal
Abstract: Growing urbanisation in India has led to the increasing development of high-rise buildings. To maintain the building aesthetics, the outdoor air conditioner (AC) units are stacked within a recessed space. The heat rejected from these outdoor units (ODU) leads to an increase in air temperature of the recessed space. This causes inefficient working of AC units. The paper reports the difference in results when on-site measurement data were compared to CFD simulation results. The on-site measurements were taken for six storeys of an eleven-storey building. The different turbulence models were studied, and it was concluded that the NK turbulence model had the least percentage difference of 8.89% when compared to the site data. Further, NK model was used to study the placement of ODUs in recessed spaces having varying depth and width. When the horizontal distance between the ODUs increased by 1m, maximum condenser on-coil temperatures reduced by 6°C. The studies concluded that, even by allocating lesser area to the recessed space, but by optimizing the depth and width of the space, the temperature increase of the microclimate can be avoided and AC efficiency can be maintained.

Daylight performance of perforated screen (2020)

Khushbu Bhatt, Jeevan Mohan
Abstract: The perforated screen is an architectural element/device that helps to protect from direct sunlight, allows visual contact, and acts as a shading device. With the advancement in technology, various versions of shading devices are being used on building façade to reduce the impact of harsh sunlight. It is important to evaluate the simulation capabilities to quantify the performance of shading devices with complex geometries. The purpose of this study is to identify the daylight simulation method for a perforated screen, which can help to make design-based decisions at various stages of design. To understand the accuracy of simulation’s result this study compares two RADIANCE based simulation techniques with the actual on-site illuminance measured data. For the daylight simulation Rhino 6 (Robert McNeel & Associates, 2018) software with Honey Bee Plus, the plug-in is used to simulate through 2-phase and 5-phase simulation methods. To generate Bidirectional scattering distribution function (BSDF) data for the 5-phase method, WINDOW 7.7 LBNL (Berkeley Lab, 2015) software is used. In the second phase of the research process, annual simulations were performed to understand the impact of various parameters of the screen, such as thickness, geometry, and distribution of voids. Comparing the results of 2-phase and 5-phase simulation method with the actual measured data shows that the 2-phase method predicts around 30% error, and 5-phase results follow a similar trend as actual results with around 14% error in the results. Co-relating results of different thicknesses and geometry show that thickness has a significant impact on the daylight performance of the screen and geometry did not translate as a significant factor.

Evaluation of Daylight and Occupant visual discomfort in Instituional Buildings (2020)

Kaushik Jayaveeran, Marshal Maskarenj
Abstract: This research aims to validate the existing and widely used glare metrics for Indian context, namely, Visual Comfort Probability (VCP), Daylight Glare Index (DGI), CIE Glare Index (CGI), Unified Glare Rating (UGR) and Daylight Glare Probability (DGP). Dataset is derived from controlled experimental set-up, where subjective evaluation of various luminous environment is conducted. High dynamic range photogrammetry was used for mapping the glare from LED sources. The luminous map data and participants subjective evaluation is compared against each other to evaluate glare metric. For the purpose of this study, robustness is defined as the ability of a metric to assess subjective glare perception for Indian context considering influence of various temporal variable such as effect of caffeine ingestion, previous luminous environment exposure and effect of fatigue using rank correlation and logistic regression analysis. The results exhibited high degree of scatter when subjective evaluation were compared against various glare scene pertaining to a scale of above mentioned glare indices. This scatter indicated that there are more variables that influence glare perception besides the commonly used, in the glare equation which needs to be accounted for. However, future work needs to be carried out to validate this research.

Energy saving potential of varied sizes of office spaces and its cost implication (2020)

Gaurav Vakil, Autif Sayyed
Abstract: The aim of this research is to create an integrated decision-making strategy for achieving Net Zero Energy in Varied Sizes of Office Spaces, by identifying strategies that are both energy and cost efficient. The proposed integrated design approach is applied to three varied sizes of high-rise office buildings; bifurcated as Small Office Building comprising of four-floors having 500m2 floor plate area, Medium office Building comprising 10 floors having 1500m2 of floor plate area each and Large Office Building having 20 floors of 2500m2 of floor plate area each, located in Ahmedabad. Energy simulations were done using Design-Builder software (Energy- Plus tool). The availability and cost of the materials and equipment were assessed with a market study.

The maximum energy savings achieved with prescriptive compliance through ECBC-Super measures as mentioned in ECBC-2017 for all three building types, having 20.6% savings for Medium Office, 17.6% for Large Office and 17.15% for Small Office type as compared to Business-as-usual case. The incremental cost and Net-present Value for all nine cases; i.e. three building type and three stringencies of ECBC-2017, were compared and, energy conservation measures prescribed for ‘ECBC minimum’ are the most optimum solution for all cases. Based on the impact of individual measures on all three types of buildings, the energy savings through Lighting Power Density is highest. It was also observed that, the impact of similar energy conservation measure of wall on Small Office Building was 2.44% greater than that of Large Office Building.

Urban energy modelling for Ahmedabad (2020)

Anmol Mathur, Rajan Rawal, Pamela Fennell
Abstract: Urban building energy models (UBEM) are important data-driven tools to support sustainable design and operations of cities, incorporating datasets from buildings and urban infrastructure. UBEMs are developed from a range of inputs on the spatial and semantic details of the buildings and the systems affecting their energy performance. Large geographical scales with finer Spatio-temporal details increase the challenges of data processing for a reliable UBEM. Thus, understanding the impact of increasing the Level of Details (LoD) of the inputs on the model outputs becomes essential. Adopting a ‘Fit-for-purpose’ approach leads to the appropriate use of the LoD having a suitable trade-off between the efforts spent on filling data gaps, model development, and the reliability of the outcomes. This research presents a framework identifying the LoD for the UBEM across occupancy, geometry, context to methodology, and calibration. A UBEM for 0.3 sq km of Ahmedabad, India is presented to support the same. The results highlight a need for a higher LoD in occupancy modelling for the residential and educational buildings, whereas a higher LoD is more important for the commercial building’s envelope characteristics. These insights become useful for developing a targeted supplementary data collection approach for the UBEM of the entire city.

Development of simulation data visualization framework for high-performance buildings (2019)

Yashima Jain, Prasad Vaidya, Saket Sarraf
Abstract: The building design community is challenged by continuously increasing energy demands, which are often combined with ambitious goals for indoor environment, environmental impact, and building costs. From an architect’s standpoint, the output results from simulation tools are mainly alpha-numeric charts that are difficult to use and interpret and are generally composed of enormous quantities of results data. These data have a huge potential for design improvement if communicated effectively. Poor data plotting limits the ability to compare, analyse and explore in depth to reveal hidden information, and thus leads to weak decision making. A robust literature review of data representation theory and past work in the development of the representation of thermal and energy simulation results was done. It suggests that there is a need to organize the already available fragmented efforts based on various design stages and design discipline. The methodology includes interviews with practitioners, analysis of current state-of-the-art spatial representations, selection of metrics, and developing the representations for a test case building. Based on the interviews and analysis of the current representations, a theoretical framework was proposed for energy efficiency visualizations. Further, a framework of representations which can be followed to represent energy simulation data to architects has also been proposed. This framework is a combination of representation of various options along x-axis, floors of the building along y-axis and representation of data for various metrics along the z-axis. This provides consistency in the representations, a background map that architects are familiar with so that data can be displayed for easy communication, and options can be compared. The results show not only that such representation can lead to a better understanding of the relationship between the building elements and its performance, but that certain metrics are more useful to stakeholders and combination or overlays of such metrics can lead to better understanding of design performance. This research is an attempt to bridge the communication gap between architects and energy modelers with energy information simulation results represented spatially.

Evaluating the UK-Building Performance Evaluation (UK–BPE) Methodology for Residential Buildings in India (2019)

Sahil Verma, Sanyogita Manu
Abstract: India’s energy demand is growing due to transforming economy. Lifestyle and consumption behavior is also changing with economic growth. Because of the accelerated economy, the country is urbanizing rapidly. Recent studies show that by 2030, India’s energy demand in the residential sector will be four-fold as compared to the energy demand in 2010. To reduce the future energy demand in the residential sector, the green building rating systems like IGBC, GRIHA, and LEED came up with design guidelines specifically for residential buildings. IGBC demonstrated savings of 30% to 40% on energy cost. However, research continually demonstrates that green building rating systems do not always ensure targeted energy performance and the way of identifying and addressing the performance gap is through building performance evaluation (BPE). This study was part of a project called Learn-BPE. This is UK- India research project which aims to undertake collaborative research and educational activities to develop the methodology to evaluate the actual performance of buildings from a technical and occupant perspective. This study reports the findings from BPE carried out on an IGBC green home platinum-rated building located in Ahmedabad, India. Monitoring and on-site measurements were carried out from 15th Jan 2019 to 28th Jan 2019. UK-BPE methodology was adopted for evaluation and through the case study, the methodology was evaluated to check its relevance and appropriateness for residential building in India. Annual and monthly energy consumption were analysed. PM2.5, PM10 and CO2 levels were monitored for indoor air quality. Thermal comfort and occupant’s satisfaction survey along with instantaneous measurements of indoor environmental variables were taken. Further, to understand the gap in UK-BPE methodology, a matrix was developed by comparing different rating system applicable to the residential building in India. This matrix helped in identifying the different performance metrics that are used by different rating systems in India. The rating systems considered for developing the matrix were IGBC green- (homes, affordable housing, residential societies), GRIHA- (v2015, existing building, affordable housing, SVA), LEED v4.1 (residential design and construction: multifamily core and shell, adapted for India) and Eco-Niwas Samhita 2018. The matrix helped in finding the gap in performance metric in UK-BPE and Indian rating systems and recommendations were also provided to fill the gap. This study was carried out to evaluate the UK-BPE methodology for residential green building in India. This study helped in understanding the requirements of green building rating system in India and helped in identifying the gap in UK-BPE methods for the Indian context. An extensive study was done for identifying the gaps in methodology and suggestions are given to bridge the gap. To evaluate the performance of the building, UK-BPE methodology was used and the project chooses a prescriptive approach for compliance. The building studied was located in Ahmedabad and its performance was evaluated based on the performance goals as per IGBC green homes and suggested methodology. After analysing all the aspects of case study building, it was found that building was performing and built as per the IGBC criteria requirements, but still there was gap observed in the operation and design due to which occupants were not using them as intended or do not help in energy savings. From the building study, it was concluded that evaluating criteria based upon prescriptive approach alone cannot determine the performance of the building, proper monitoring of that parameter needs to be done to know the actual performance of the building.

Comparative testing of BQEET (Building Quick Energy Estimation Tool) that quantifies the reduction in cooling energy due to passive strategies for 59 Indian cities (2019)

Sanchi Pathella, Prasad Vaidya
Abstract: Earlier studies have used Thermal Autonomy (TA) and Residual Cooling Degree Days (RCDD) to estimate the cooling potential of passive cooling techniques. But the cooling energy reduction due to passive strategies was not quantified. The BQEET tool uses the TM41 CIBSE method based on Cooling Degree Days (CDD) to calculate the CDD values using the appropriate Balance Point Temperature (BPT). The tool then estimates the reduction in cooling energy consumption due to passive strategies. This tool is targeted to help architects and designers to select suitable passive strategies in the early design stages. It is also targeted to help planners and policy makers to estimate energy use and cost savings at a large scale, to formulate and implement new policies. Limited testing of BQEET was done by Desai, using the ASHRAE Guideline 14 and IPMVP, since a robust procedure was not within the scope of the study. The Guideline 14 and IPMVP methodology are intended for calibrating the results of a simulation with an existing building and not for testing a simulation software. Hence, there is a need to test the BQEET tool in a robust way. The comparative testing in this study has been carried out for two types of buildings, air-conditioned and mixed mode building operating with passive cooling strategies. The testing procedures start by using the HERS BESTEST models of typical US buildings and modifying them using reference building models for the Indian context. There are no procedures for mixed mode buildings in HERS BESTEST, and no reference models for mixed mode buildings have been developed for India. Therefore, this study defines the mixed mode operation cases and tests them for the number of discomfort hours. The air-conditioned cases are compared for their energy end-uses. The lighting and equipment energy in BQEET are similar to the EnergyPlus results. But the cooling energy in BQEET is 400% higher than that of EnergyPlus. In order to analyse the variation in the cooling energy results, a critical analysis of the components contributing to the cooling energy is carried out. A building physics investigation of the cooling energy calculations of fabric gain, solar gain, fan gain and latent gain due to infiltration and occupancy has been carried out in the TM41 CIBSE method based on Cooling Degree Days, EnergyPlus and BQEET. The errors in the cooling energy calculations of the BQEET tool are identified, quantified and analysed. Modifications in the algorithm of the tool or in the BQEET tool itself are proposed.

Correlating energy efficiency, environmental impact and ability to provide comfort for Room Air Conditioners (2019)

Nidhi Rai Jain, Rajan Rawal
Abstract: In India, the energy end-use is anticipated to increase by 56% from 2014 to 2050. It shares 12% of total carbon emissions in the world by Room Air Conditioners (RACs). As increase in energy production using fossil fuels has an adverse effect on climate, there is an immediate need to focus on mitigation scenario. This scenario counts on the change of refrigerant, improvements in system design efficiency and operational approach. Growth in urbanization and rising income is persuading the use of RACs. Seasonal Energy Efficiency Ratio (SEER) is the most used method to quantify efficiency of RAC. Environmental impact of the system is still unexplored. This study is conducted to develop a correlation between indoor comfort temperature, the energy efficiency of RAC and total carbon emissions (direct & indirect) considering its life span. Even with constant improvements in the energy efficiency of RAC using low GWP refrigerants, there is gap observed between the actual performance of the system and total emissions leading to climate change. The purpose of this study is to correlate annual cooling energy demand (w.r.t. comfort set-point temperatures) to energy efficiency and total emissions by a RAC for any city in India. The study was conducted in four stages - literature study, data collection, calculation methods and results. Initially, relevant metrics were identified from past work to quantify the parameters. In the next step, 12 Indian cities were selected based on GDP growth followed by Cooling Degree Days (CDD). Four RAC units were selected based on findings from market survey of 282 RAC systems available in the country. In the third stage, Indian Seasonal Energy Efficiency Ratio (ISEER) and Cooling Seasonal Energy Consumption (CSEC) were calculated for 12 cities using ISO 16358-1 and outdoor temperature bin hours. Carbon emissions were calculated using Total Equivalent Warming Impact (TEWI) score which comprises of direct (refrigerants) and indirect (energy consumption) emissions considering its life span. A method was proposed to calculate ISEER and CSEC using adaptive setpoints with few research gaps identified. The adaptive setpoints were calculated based on Indian Method of Adaptive Comfort (IMAC). Lastly, the results obtained shows that indirect emissions dominate in TEWI score which is calculated using CSEC (kWh). A more significant variations were observed in CSEC in different cities and different comfort models as compared to RACs with different ISEER. This study develops a methodology to calculate ISEER beyond BEE standard method and propose CSEC as a metric for different cities and different comfort models using indoor setpoints. The direct emissions were observed constant in all cities, the variations observed was because of indirect emissions (kWh). Thus, there is need to focus more on CSEC (kWh) than low GWP refrigerant to reduce total carbon emissions which causes climate change.

Energy Use and Thermal Comfort in Affordable Housing in Ahmedabad, India: A Case Study (2019)

Garima Kamra, Sanyogita Manu
Abstract: ‘Housing for all – 2022’, a large-scale housing initiative was launched in 2015 by the Indian government for providing quality affordable housing to the lower economic segment by the year 2022. Occupant thermal comfort is one of the significant aspects of liveability and applies to affordable housing as well. These houses have low energy consumption as of now, however, as incomes and comfort expectations increase, energy use and related costs in this segment are expected to surge. Comfort field studies in affordable houses in India remains a subject largely neglected. This report discusses the findings of the thermal comfort conditions and energy use of 20 houses in three affordable housing developments located in Ahmedabad, India. The results discussed are from data collected using three methods. These involved long-term monitoring of household energy use and indoor environment parameters (air temperature and relative humidity (RH)), instantaneous measurements of thermal comfort conditions (air temperature, RH, air velocity, globe temperature) and right-here-right-now thermal comfort surveys. It was observed that average daily energy use ranged from 0.5 - 6.75 kWh and was dependent on appliance ownership and occupant behavior. Energy use was base load driven in these houses. 65% of the occupants reported being comfortable in their thermal environment during the survey period. The conclusions from this study give an insight into the seasonal and daily usage patterns of energy use in the affordable housing segment and potential for savings. It also discusses the prevalent thermal comfort conditions and adaptive measures adopted by the occupants.

Evaluation & Analysis Of Indirect-Direct Evaporative Cooler (IDEC) In Hot-Dry Climate (2019)

Shoumik Desai, Rajan Rawal
Abstract: The commercial and residential sector demands high cooling requirement, which is mostly achieved by using conventional cooling systems like split ACs, chillers or VRF. These systems currently produce 100 MT of CO2 per annum and hence contribute significantly to carbon emissions. To mitigate such environmental impacts, using low energy cooling systems like an indirect-direct evaporative cooling system (IDEC) is an energy efficient alternative as it uses energy only for pumping water and blowing air. The evaporative cooling technology works on the principles of heat and mass transfer between air and cooling water. Direct evaporative coolers (DEC) works based on mechanical and thermal contact between air and water, while IDEC works based on heat and mass transfer between two streams of air, separated by a heat transfer surface with a dry side where only air is cooling and a wet side where both air and water are cooling (Porumb, Ungure, Fechete, Alexandru, & Mugur, 2016). As the capacity of air to absorb vapor is directly related to its humidity, evaporative coolers are most suitable for regions where high temperature coincides with low air humidity. It can cool air using much lesser energy than vapor compression techniques. This study evaluates the cooling performance of IDECs. The study was conducted in the industrial food processing unit where 61,800 CFM IDEC system is serving 465 m^2 of area. Internal loads are very high owing to the usage of gas furnace and fryers for cooking activity. The wet bulb effectiveness (WBE %) was calculated from the hourly measured values of air temperature (Ta °C) and relative humidity (RH %). These parameters were measured at inlet and supply air. Energy consumption of the IDEC system, air blower fan, and water pump were monitored every hour. Thermal comfort surveys were conducted in the space being served by IDEC. This was done to establish a relation between the system effectiveness, the cooling energy consumption and degree of occupants’ comfort. It was found that IDEC was able to achieve ΔTa of 5- 6 °C, saturation deficit of 30-35%, water consumption of 62.0 lit/hour with an average COP of 5. During August-October WBE varied from 55-83% with an energy consumption range of 29-30 kWh. Whereas, for November-December, WBE varied from 41-67% with energy consumption range of 23-28 kWh. However, despite this high WBE, 71% of the subjects voted the thermal environment to be either “slightly warm (+1)”, “warm (+2)” or “hot (+3)” on 7-point thermal sensation scale and 78% of the subjects wanted to be cooler. On further investigation, it was found that the IDEC was only able to produce 44,743 CFM whereas it was designed for 61,800 CFM. This could be because the system maintenance hasn’t been done for a long time. However, if the IDEC achieved designed airflow then the possibilities are that the WBE might not vary much, but an additional 27% airflow might help counter the heat generated by the cooking process. Also, the system might be able to satisfy the occupant thermal comfort expectations

Analysis of flow patterns using water-table apparatus by varying the model scale (2019)

Vijay Chawan, Rashmin Damle
Abstract: Natural Ventilation is one of the passive strategy for maintaining the occupant’s thermal comfort through fresh outdoor air. It also helps to reduce building energy required for space conditioning. The ventilation of occupied building spaces has two main purposes: one is to provide acceptable indoor air quality which is primarily based on the supply of fresh air and the removal or dilution of indoor pollutant concentration; the other is to provide thermal comfort to the occupants. In today’s scenario, people spend most of their time in indoor environments such as home or offices. Indoor contaminants like volatile organic compounds and stale air cause health problems and results in the so-called sick building syndrome. Naturally ventilated buildings provide adequate ventilation rates consistent with acceptable indoor air quality. Evaluating ventilation performance of a building is challenging due to the difficulty in prediction of indoor air movement under varying outdoor climatic conditions. In this context, water-table acts as effective tool for predicting the ventilation performance of buildings. A water-table is an inexpensive apparatus which may be used to predict airflow patterns for wind-induced unidirectional air flows. It is observed in literature that most of the water-table studies are based on qualitative analysis. Recently, a methodology for quantification of flow patterns generated in the water-table apparatus has been reported. This study involved water-table study with three basic configurations along with complex multizone apartment. Different ventilation metrics were developed for analysing the flow patterns. However, the effect of model scale on the derived ventilation metrics was not considered in this work. This is also observed with other studies in the literature. In view of above, this work focusses on estimating the limiting size of a scaled building model with respect to the water-table apparatus. Different configurations with openings on single side (SS), adjacent side (AS) and opposite side (OS) are studied using model scales ranging from 1:20 to 1:80. It is observed that model scales from 1:20 to 1:60 followed the same trend in terms of the evaluated ventilation metrics. Significant variation in results in terms of ventilation metrics are observed for model scales 1:70 and 1:80. Additional experiments are also carried out to study the effect of speed and aspect ratio. The findings of this research could be useful in selection of appropriate scale for conducting water-table experiments.

Estimating air leakage for star rated hotels in Ahmedabad using blower door method (2019)

Ankit Debnath, Rashmin Damle
Abstract: With a growing awareness of energy efficiency in the hotel industry by the Indian government and hoteliers, energy performance is becoming an increasingly important aspect with India’s emergence as a global tourism hub. Energy audit studies conducted by local agencies and the Energy Department of India shows that hotels have a potential of reducing 20-30% of energy use without compromising the quality of hospitality services. For a correctly sized HVAC system complemented with an airtight envelope can help in substantial energy savings by reducing cooling demands.

In this work, air leakage characteristics of 30 air-conditioned double occupancy hotel rooms in Ahmedabad are studied. The studied dataset compiled consists of 18 rooms with split ACs, 9 rooms with central ACs and 3 rooms with window AC unit. These hotel rooms were tested using blower door method (pressurization/depressurization at 50 Pa) to find out their leakage characteristics. To check the airtightness of a hotel room blower door method is a quick and economical method. Relatively quick and accurate results are obtained by blower door. This research work adopts blower door method to measure leakage characteristics. The test results obtained at 50Pa are automatically converted in the form of effective leakage area (ELA) normalized at 4Pa just after the test is completed. The ACH due to infiltration is then modelled using simulation software for the respective geometry to find energy impact and potential financial savings.

The work was able to identify the correlation between ACH due to infiltration and multiple varying envelope characteristics like WWR, floor area, HVAC systems, window frame and tariff. The measured ACH due to infiltration for the rooms compared with the international standards for airtightness. Majority of the rooms were found to be airtight as compared with the most stringent standard. Factors such as window perimeter area and type of window i.e., fixed and operable for leaky hotel rooms helped in minimizing the infiltration. However, making the room airtight by compromising the outdoor view. Low tariffed rooms with split systems are airtight due to low WWR of typical 22%. Higher tariffed hotel rooms with centralized system were observed to be airtight. These rooms were newly built with bigger floor areas. For the hotel rooms studied, simulations show that the impact of air leakage on energy consumption is not substantial

Retrofitting an Existing School Building – A Case of Aga Khan Academy, Hyderabad (2018)

Vertika Srivastav, Swati Puchalapalli, Sanyogita Manu
Abstract: Retrofit of naturally ventilated educational building is an effective solution to the thermal and visual discomfort problems of the occupants. The Aga Khan Academy is a residential school, located in outskirts of Hyderabad, India. The school functions in an International Baccalaureate (IB) Curriculum. The building is IGBC platinum rated. The project deals with the retrofit procedure of the Senior Academic Block, which is naturally ventilated. The procedure contains steps: First, assessment of the existing conditions through climate analysis, thermal images, measurements & occupant surveys. Second, presenting retrofit design proposal and further optimizing and prioritizing scenarios based on thermal and daylighting simulations. The tools used for the analysis are: EDSL TAS and LightStanza.

The methodology is divided into four phases. The procedure involves: Assessing the existing conditions through climate analysis, measurement of surface temperature, indoor dry bulb temperature, humidity, daylight levels & occupant surveys; Developing retrofit options and testing them out using simulation tools: EDSL TAS & LightStanza, to quantify their impact on occupant thermal and visual comfort.

The measure taken include passive strategies related to the existing building envelop and addition of a low energy cooling system. Another aspect of this project is to enhance the daylight levels inside the classroom to provide occupants with a blind and glare free environment. The strategies that are recommended for enhancement of thermal and visual comfort are:

- Insulation of Aluminium Panel using 10 mm PU board insulation which achieved 40% comfort hours

- Adding horizontal louvers with slits in between on the windows facing west direction with achieved 50% comfort hours.

- Replacing Pinhead security glass with clear glass which helped to achieve 53% comfort hours along with sDA300/50 is achieved for at least 55% of the space & ASE1000/250 of no more than 10%.

- Converting fixed windows to operable windows which operate to 100% of the opening area in the main windows for ground floor and the clerestory windows combined with top and mid pane has 100% operable area on the first floor. This strategy helped to achieve 65% comfort hours.

- Adding a low energy cooling system – BreezeAir Evaporative Cooler to all the classrooms in a centralized manner helping to achieve 77% comfort hours.

Evaluation of daylight performance of the new workshop building at CEPT University, Ahmedabad (2018)

Vasudha Sunger, Prasad Vaidya
Abstract: India is experiencing urbanization at a faster rate, majority of building energy is consumed by cooling, ventilation through fans and artificial lighting. Daylighting can be a key driver in conserving energy with saving potential up to 45%. It has the potential to cut energy use, reduce peak demand, reduce the cooling energy costs and create a comfortable indoor environment. As per ECBC 2017, the lighting power density (LPD) for a workshop facility is 14 W/sq. m, which is second highest out of all the LPD requirements and can have high lighting energy use. This study evaluated the daylight performance by calculating the potential lighting savings and assessing the visual comfort of the newly built workshop building at CEPT University, Ahmedabad, India. This study included measurement of illuminance and surface material characteristics, lighting usage patterns, a calibrated daylight model, and annual simulations using LightStanza (A cloud based daylighting simulation software powered by Radiance). The daylight model was also used to quantify the impact of important design decisions in the building. The calibrated model of the building has a RMSE (root mean square error) of less than 4%. The workshop building is LEED v4 and ECBC 2017 daylight compliant. In terms of glare related visual comfort, it faces no shading or harsh sun issues for most of the year but the spaces are likely to experience glare issues between 5-6 PM during the summer months. If the workshop building is operated as per the existing lighting pattern and usage, it will achieve cost savings of Rs. 86424 annually in lighting energy consumption when compared to the building that has lights on for all occupied hours. However, the building is likely to achieve more lighting energy savings with automated controls.

Estimation of Ventilation Rates in Class-rooms in Schools in Ahmedabad (2018)

Sandhiya Jayakumar, Michael Apte
Abstract: Prolonged exposure to indoor air pollution may affect the health, comfort and performance of the occupants. Failing to address Indoor Air Quality (IAQ) problems may lead to short-term health problems like-irritation of the eyes, nose and throat, headaches, dizziness, and fatigue and long-term health issues like-respiratory disease, heart problems and cancer. The health effects may vary for different individuals depending on factors like age and medical conditions, children being young and sensitive to the environment, are more susceptible to the same. Hence, suggested ventilation rates have to be maintained in Schools. The primary focus of this research is to estimate the ventilation rates in schools in Ahmedabad by using the carbon dioxide exhaled by the occupants, using steady state mass balance method and estimating the ventilation rates. The estimated air flow in the naturally ventilated and air conditioned classrooms in Ahmedabad had vastly different results. The air flow in the naturally ventilated classrooms was between 61.5 l/s per person to 15.6 l/s per person. The air flow in air conditioned classrooms was 0.9 l/s per person and 1.0 l/s per person. The air flow in naturally ventilated classrooms are excessively high, more than meeting prescribed rates, while air flow in air conditioned classrooms is far below the prescribed outdoor air rate per person as provided in ASHRAE (2016) and Bureau of Indian Standards (2016). The sampling for this research is convenient sampling due to the time constraint, hence this study will not be a representative sample of either Ahmedabad or India. It is also noted that increasing the ventilation rates with highly contaminated outdoor air is also risky to the health. In such a case, the outdoor air has to be cleaned using energy efficient air purifiers before introducing it into the indoor environment. Optimum ventilation rates may lead to high building operation cost, but this can be avoided by reducing pollution load in the indoor air.

Experimental Investigation of the Terracotta Tubes Based Direct Evaporative Cooling System (2018)

Sahil priyadarshi, Rashmin Damle
Abstract: Evaporative coolers have many applications in the fields of refrigeration, air-conditioning and power-plants. These systems typically work best under hot and dry climatic conditions. Studies have shown direct implications of operating parameters on cooling capacity, and cooling energy consumption. The purpose of this study was to evaluate the cooling performance of terracotta tubes (pots) based direct evaporative cooling system (DECS). The cooling performance is evaluated in terms of wet-bulb efficiency under different operating conditions (air-temperature, relative humidity, and air flow rate) for an indoor application. Further, the cooling capacity (in Watt) and Coefficient of Performance (COP) of the system is calculated and the comparison with other evaporative cooling technologies is done to better understand the system performance. The research methodology consists of four major parts. These are experimental set-up, conducting experiments, results & data analysis, and future recommendations. The experiments were conducted under real ambient conditions in four modes. In first mode, fully saturated (100% wet) pots without water flow at different air flow rates were tested. In second mode, dry pots with water flow at different air flow rates were used. In third mode, dry pots at variable water flow rates at constant air flow rate were used to conduct experiments. In fourth mode, the impact of geometry on the cooling performance was investigated by using two types of pots (type-A and type-B). The performance governing parameters like air temperature, relative humidity, air flow rate, water consumption; voltage and current supplied to the fan and water pump were measured. The results show that on using type-A pots, the system achieves a maximum wet-bulb efficiency of 85%. The inlet (hot) air temperature and RH are in the range of 28.1 – 37.6 °C and 30.9% – 70.5% respectively under 600 cfm of air flow rate and at 950 L/h of water flow rate. The temperature drop achieved by the system on using type-A pots varies from 1.8 – 9.8 °C. The water consumed under this test condition for an operational period of 9-hours is 78 L. However, on using type-B pots, maximum wet bulb effectiveness of 80 % is attained under similar inlet air conditions (temperature & RH) and same air and water flow rate as of type-A pots. The temperature drop achieved by the system on using type-B pots varies from 1.9 – 8.0 °C. The water consumed under the same test condition for an operational period of 9-hours is 94 L. The power consumed by the system varies from 308.6–317.7 W depending on different experimentation modes and test conditions. The COP of the system vary from 1.12-27.11 depending upon the test conditions. On comparing with other evaporative cooling technologies found in literature, terracotta tubes based DECS exhibits high wet-bulb efficiency.

Quantification of Airflow Pattern in a Naturally Ventilated Building Simulated in a Water Table Apparatus (2018)

Pooja Shriram Mundhe, Rashmin Damle
Abstract: Today, most of the people spend 80-90% of the time indoors either in the office or at home. Indoor air is contaminated by human activities and building materials like paints, furnishings, adhesives which emit volatile organic compounds. Exposure to these compounds has a short and long-term impact on health. Inadequate ventilation also causes Sick Building Syndrome. It is therefore important to provide the healthy indoor environment, as it has an impact on the productivity of people. Acceptable indoor air quality can be maintained by operating a building in natural ventilation. However, predicting the performance of naturally ventilated buildings is challenging, as the parameters governing the airflow, such as temperature and wind, are highly variable over time. Water table is an apparatus that helps to analyze natural ventilation in buildings due to wind effect. It is inexpensive, easily accessible and provides instantaneous two-dimensional results of airflow patterns in and around the building. The current research focuses on quantifying the qualitative data available from the water table experiment and developing ventilation metrics to quantify air movement within a physical building model simulated in the apparatus. The quantitative results of the algorithm will help to make design decisions in terms of opening sizes, orientation, and appropriate positioning of openings in the building. This will be of utility for educational purposes, serving architects, energy consultants and practicing engineers. The ventilation metric and the algorithm quantify the visual data from the water table and will assist in arriving at design solutions optimized for wind-driven natural ventilation.

Measuring ventilation rates & leakage in building using Blower door method (2018)

Nikhilesh Singh Bist, Michael Apte
Abstract: The need to achieve thermal comfort in residences and strong dependence of air conditioning systems has led to huge energy consumption. In order to reduce the energy consumption of residences and properly size the air conditioners, air leakage needs to be reduced by tighten the building envelope. One such approach to quantify the air leakage is the use of blower door, which uses a powerful calibrated fan to depressurize or pressurize the house at an induced pressure to measure air flow (air leakage) from the house. Blower door technique is independent of climatic condition unlike other ventilation measurement techniques such as use of tracer gas decay method, steady state mass balance method.

In this study, 23 residences of Ahmedabad, 12 bungalows and 11 apartments were measured for air leakage. The study is also a first step towards developing methodology to conduct an air tightness test in residential buildings. For comparison, mean normalized leakage (metric for air leakage) of the 23-measured residence was 2.1, which is comparable in average with US homes. When compared to International standards like LEED homes, IECC, Passivhaus, none of the 23 measured residences comply with the standards. Due to dwindling number of observations, there is very less variation in mean effective leakage area of bungalows and apartments, hence it cannot be used to quantify the air leakage of building stock of Ahmedabad. But, due to old age construction, bungalows have more leakages than apartments. High air flow rates can be observed in buildings with intentional openings, inferior quality windows and cracks on walls. Retrofitting those windows, sealing the intentional openings in an air-conditioned space can lead to huge energy savings for air-conditioned spaces.

Assessing Energy Savings and Payback Period for 2017 version of Energy Conservation Building Code of India. (2018)

Mansi Parekh, Prasad Vaidya
Abstract: The revised version of Energy Conservation Building Code (ECBC) was published in June 2017 after ten years. The new version of ECBC goes beyond minimum compliance, and has two additional levels of ECBC ‘plus’ and ‘super’. ECBC includes a prescriptive compliance path and alternative Whole Building Performance (WBP) compliance path with energy use intensity ratios. This thesis assesses the energy savings and payback period for the prescriptive versions of ECBC-2017, minimum compliance, plus and super levels for an office building in Vishakhapatnam. It also demonstrates alternative cost optimized solutions for these three levels of ECBC using the WBP approach.

The office building is a real building in design stage according to the current construction trends that do not comply with even the previous ECBC version of 2007. Energy simulations are done in eQuest DOE 2.2. The availability & cost of equipment and materials to achieve the ECBC 2017 levels is assessed with a market survey.

Using the prescriptive compliance approach the ECBC, ECBC plus and ECBC super version of the office building in Vishakhapatnam, the energy savings achieved are 17%, 25% and 33% respectively as compared to the base case current practice building. The incremental cost (₹/m2) for these are 845, 1229, and 1454 and the payback periods are 4.3, 4.3 and 3.9 years respectively.

Using the Whole Building Performance approach, it was possible to achieve the compliance of ECBC, ECBC plus and ECBC super levels with much lower incremental cost a compared to the prescriptive version. The energy savings achieved for these bundles for ECBC minimum, plus and ECBC super are 17%, 29% and 38 % and the net incremental cost (₹/m2) are 87 ,292 and 429 with payback period of 0.4, 1 and 1.3 years. Based on the results of the individual measures considered in this study and current technologies available in the market, this study demonstrates an opportunity to achieve energy savings higher than the ECBC super level. Incorporating such measures will yield energy savings higher than ECBC super levels, and such measures could be considered in the design of Net Zero Energy buildings.

Evaluating Methodology for Performance Evaluation of Non-Residential Buildings in India (2018)

Maaz Dixit, Sanyogita Manu, Rajat Gupta
Abstract: Buildings consume 33% of total energy (24% domestic and 9% commercial) in India and this is growing at 8% per annum. Reliance on unsustainable energy and increasing demand for energy is a major concern in buildings in India. Although there have been green buildings built in India, proper implementation and use of the same is not seen. This leads to higher than predicted energy use. There have been limited studies done in India prevailing how to design and operate an energy efficient building. Building Performance Evaluation is essential to reduce this gap and help buildings perform better. Despite the improvements in whole building systems and services and energy efficient building design and implementation, there is a growing gap observed between the intended and actual performance of buildings, leading to higher or lower than expected energy use. The project will develop and validate post-occupancy BPE methodology for Indian buildings through field studies. The stakeholders benefited from this study are energy experts & designers, building occupant and owners. This will help to close the loop and help feed data for the next design as well as help the existing buildings perform better. The actual performance of a LEED Platinum rated and GRIHA 5-star rated institutional building (Academic block 1-A and 1-B in Manipal University, Jaipur) through on-site measurements, monitored energy data and building use by the occupants. This field study was carried out in the first two weeks of February (6th- 20th February). Energy performance index for this building is 26.5 kWh/m2· year which is 2% better compared to targeted savings according to GRIHA 5-star rating. The environmental parameter of the building was monitored (dry bulb temperature, CO2, and RH). All spaces were thermally comfortable according to NBC 2005. Most spaces had acceptable noise levels except for open office spaces and classrooms on the second & third floor (NBC 2005). 79% of the users from the surveyed population felt the design met their needs. According to the survey of user control interface, all space types had ease of access to the interface. However, certain spaces (classroom, personal cabin, and open office) did not have access to thermostat control. Constant involvement of the facilities management team and proper use of building according to the design helps maintain the building performance. For further evaluation projects of green-rated buildings, field study measurements are a challenge. A proper monitoring plan will help in more robust and accurate measurements on site. Detailed analysis of the submittals for rating systems is crucial to execute a better BPE. Some additions and alternations are required in the customized BPE method which will lead to better performance evaluation in short period of time.

Energy use prediction of buildings with different methods of calculating SHGC of shaded windows (2018)

Kurva Dhonde, Rashmin Damle
Abstract: Building energy simulations are used for carrying out detailed calculations for the energy use prediction of the building. A building comprises of several load components like people, equipment, electrical lights, HVAC systems, walls, roofs and fenestrations. Several studies in the past have shown that the fenestrations account for significant heat load increment in the building. The heat gained through fenestrations in the building can be identified through simulations. To accurately predict the heat gains through fenestrations, details of the fenestration like window opening size, the glazing material, window frame material, window frame size, shape and size of the shading devices are given as an input to the simulation engine. Also, the other important inputs for the glazing are the U-value and the solar heat gain coefficient (SHGC) of the glazing material. The SHGC value considered in the simulation is typically that is provided by the manufacturers. This values are derived under standard testing conditions prescribed by associations like the National Fenestration Rating Council (NFRC). And, the shading devices are additionally modelled to identify the impact of solar gain. However, there are different calculation methods that take into account the effects of adding shading devices and provide combined value of SHGC. This is done by taking into account the manufacturer’s SHGC value and the dimensions of shading device used. This gives an effective SHGC value that can be considered as an input to the simulation without modelling the shading devices. Two of such methods are studied in this research and compared with the simulation results. The impact of SHGC value through two different methods are studied in terms of solar gains (kWh) through fenestration and cooling energy. The results are also compared with the results of the simulation model in which the shading devices are modelled and the manufacturer’s SHGC value is considered instead of effective SHGC value. Further, the impact on cooling energy reduction is determined and compared for different latitudes, climates and overhang depth. The results show that the cooling energy reduction obtained from the methods with detailed heat transfer mechanisms are closer to the results obtained from the simulation with the physical shading device. Therefore, the generalization of the SHGC formula in the other method is not appropriate.

Quantifying the cooling energy reduction due to three passive strategies for Indian cities (2018)

Arjun Desai, Prasad Vaidya
Abstract: Past studies have quantified the potential of various passive design strategies to achieve thermal autonomy. Bhadra, Vaidya, & Sarraf (2017) have shown that for 60 cities in India, minimum thermal autonomy calculated by using the thermostat set point as the benchmark, is at 12% for night cooling, 75% for evaporative cooling, 28% for ground cooling and 32% for radiant cooling. This thesis takes that approach further and quantifies the reduction in cooling energy due to three passive strategies, using the CIBSE method with Cooling Degree Days (CDD) for 60 Indian cities.

Three passive strategies: night ventilation, comfort ventilation and evaporative cooling are considered for mixed mode institutional buildings in India. Evaporative cooling is further divided into evaporative precooling and simple evaporative cooling. Using the CIBSE TM41, the Balance Point Temperature (BPT) for two different versions of Indian buildings is established based on different thermal comfort models: 1) buildings complying with the latest energy code i.e. Energy Conservation Building Code (ECBC 2017); 2) business-as-usual buildings in India. Using these BPT values and the latest TMY files, first CCD values are calculated for fully air-conditioned buildings. Then, the residual CDD for the three passive design strategies are calculated. Cooling energy consumption is then calculated for all the cases for the 60 cities.

This study calculates two versions of BPT for Indian buildings, which are more realistic that those published in the past. The results indicate the cooling energy reduction possible due to three common passive design strategies. The results show that the CDD calculated by using ASHRAE 55 comfort model is almost 1.5 times that of the earlier published values. For Ahmedabad, the value of base temperature ranges between 16-25°C for a BAU building as compared to 18.3°C constant base temperature considered by ASHRAE. Cooling energy can be reduced by upto 25% just by using passive strategies in buildings. The energy results of this method for one city are compared with Energy Plus results in terms of the annual Energy Use Intensity (EUI). The Normalised Mean Biased Error value for the CDD method used is 4.6% while the Root Mean Squared Error value is 15% which fall in the acceptable range as per ASHRAE Guideline 14 and IPMVP.

Development of affordable sensing and monitoring system for post occupancy building performance evaluation (2018)

Arihant jain, Michael Apte, Sanyogita Manu
Abstract: There is a rapid increase in the building footprint, and buildings consume 33% of the total energy in India as per a study done in 2010. Building sector has huge potential for saving energy. But before managing energy, we need to measure it. Therefore, studies related to building energy performance and its evaluation are needed in Indian context. Research has shown that intended energy performance is not equal to the actual energy performance. The Learn BPE project aims to identify and understand this energy performance gap of a building. The post occupancy building performance evaluation (BPE) requires continuous sensing and monitoring of various environmental parameters and energy consumption. The most commonly used commercially available system (HOBO data logger) can measure 3 parameters, namely- temperature, RH, and illuminance, and one external channel for other sensor types. Such equipment that are used for BPE studies have more than required accuracy and precision. Hence, sensors with higher accuracy and specifications, which cost higher, are built into them. A methodology in the form of a Do-It-Yourself, for developing an affordable sensing and monitoring solution with optimum accuracy and precision, is tailor made for BPE studies, and is flexible enough to be customized according to ones need.

Several open source hardware components were compared against each other in terms of cost, specifications, ease of use, and functionality, and after this comparative analysis, suitable hardware was selected and put together to develop the system. The open source hardware and software platform- Arduino was selected due to its wide community support, low cost hardware, and its ease of use in terms of both hardware and software. The sensors were selected on the basis of their cost, accuracy, resolution, measurement range, and response time. The temperature and RH sensors were calibrated through a calibration lab for accurate results. The illuminance sensor was not calibrated but compared against a calibrated Testo lux meter. The whole system was packaged by developing 3D printed sensor casing, and laser cut MDF board casing.

As a result, an open source data logger (OPENSDL) was developed, which could measure temperature, relative humidity, and illuminance levels. A DIY was also developed, with the help of which, any stakeholder could develop the same or similar system with custom needs and custom hardware. The DIY, hardware required, the code for running the system, all of it was uploaded on Github (https://github.com/arihant93/OPENSDL.git). The OPENSDL is an affordable, extensible and customisable solution which can be further developed and can be made more suitable for performing BPE studies against its commercial counterpart. Currently, the system is an affordable solution for educational and personal needs. The system has some issues like loose connections, loose adhesion, casing with no grip, and battery life but these can be worked upon and improved to make a better version of this system. Most of the improvements can be done just by developing a printed circuit board instead of the customised hand-made board.

Phase Change Material (PCM) application in walls and its impact on energy consumption, thermal comfort and cost benefit analysis in hot and dry climate (2017)

Shailee Goswami, Rajan Rawal
Abstract: The aim of this study is to demonstrate the impact of inside surface PCM application on walls of an office building, towards reducing the overall energy consumption, improving the thermal comfort and analysing the cost benefit potential. The office building is a G+2 floor building, which operates at change-over mixed mode on a seasonal basis. It is located at Ahmedabad, which has hot and dry climate. The heat transmission characteristics of the wall with inside surface PCM is analysed, along with added external XPS insulation, by using the testing facility of Guarded hot box. These experiments are carried out as per the ASTM C1363-05 standard test methods. Simulation software: design builder v4.7 and energy plus v8.3 are used for the whole building analysis. Three combinations of wall assemblies are analysed – internal surface PCM, internal PCM + external XPS and external XPS. The simple payback period of the PCM is calculated using the excel tool.

Experimental setup of the guarded hot box validated the PCM operation and effectiveness as envelope component and demonstrated a time lag of almost 9 hours when PCM is used.

In case of PCM with melting point 29, the latent heat stored by the thermal mass of the walls is gradually released, leading to the formation of a more stable indoor environment, while in the outdoor environment extensive temperature fluctuations exist. Software simulation analysis showed decrease in cooling energy consumption by 1.54%, The addition of external insulation in combination with internal PCM is increasing the energy savings to almost 4.02%. There was 4% increase in comfort hours (using adaptive comfort model definition) when compared to the baseline buildings with PCM installed at a hot and dry climate of India. Simple payback period calculation is resulting in high payback period of 28 years for PCMs, which can be reduced to 17.5 years combining it with insulation.

India’s Path to low carbon building stock: Estimating energy savings potential for commercial building stock (2017)

Kartikey Sharma, Saket Saraf
Abstract: The buildings sector in India accounts for a third of the total energy consumption of the country. Given the recent and anticipated economic growth in India, the sector is likely to play a more significant role in the energy sector than it currently does. As the building sector follows the “business as usual” construction practice; energy savings potential largely remains unexplored for the country. The aim of this study is to estimate the energy savings potential for two key commercial building types: Offices and Institutional establishments; across all climate zones for the country. Once the representative prototypes are derived, their energy savings potential is estimated by applying energy conservation measures on buildings typologies selected for the study by means of energy simulation. After estimating the energy savings potential for the selected building types, the savings are projected to the selected commercial building stock for the whole country. The propject savings are considered for different scenarios, and the best scenario shows the savings of 3000 GWh at national level for office and school types considered here.

Passive design indices: Quantifying the climatic potential for passive design strategies (2017)

Jaydeep Bhadra, Prasad Vaidya, Saket Saraf
Abstract: The study aims to develop indices to assess the potential of passive cooling strategies for a climate. Cooling accounts for 40% to 60% of summer energy demand in metropolitan cities with hot climates like Delhi, & air-conditioner (AC) sales in India are growing at 30% per year (CEM, 2014). Recommendations based on current climatic zone may not be appropriate as many microclimatic conditions and variations are found in few kilometres range. The currently available climate analysis tools do not explore the inter-relationships between climatic parameters such as dry-bulb temperature, dew point temperature, wind velocity and cloud cover. Earlier work showed that it is possible to develop a weather-data-based classification to map the potential of some basic passive design strategies, such as building orientation, layout, plan, window-wall ratio etc. This study takes that approach forward to establish weather-data-based indices for strategies such as evaporative cooling, comfort ventilation, radiant cooling, earth cooling, and night ventilation. Weather data variables are identified for each strategy. This study uses adaptive thermal comfort models to represent the expected indoor comfort conditions. Typical Meteorogical Year (TMY) weather data of 59 Indian cities are analysed to develop the indices. Thermal Autonomy and Discomfort Degree Days are the metrics developed to measure the potential of the passive strategies. An Excel processor and a Power BI user interface tool have been developed. These enable the user to compare the potential for strategies within a climate and compare different locations for their climatic potential for a strategy. This work can be extended to develop climate zone maps that highlight the potential for specific low energy solutions in a region.

Energy and thermal comfort evaluation of low energy cooling systems: A study for the context of office buildings (2017)

Dharini S. K., Rajan Rawal
Abstract: Low energy cooling systems are designed to consume less energy while providing adequate comfort levels. A report by the Global Buildings Performance Network (GBPN) states that data used for simulation modelling is quite inaccessible in India. It also states that for accurate assessment of potential savings, good amount of reliable field study data is required. This paper evaluates two non-refrigerant based cooling systems with such field study and experimental data for thermal comfort and energy consumption in hot and dry climatic location in India. As a representative location of this climate, experimentation and simulations are done for the city of Ahmedabad. The systems studied are a direct evaporative cooling system and a 2-stage evaporative cooling system. In-field measurements and readings taken in the month of March were used to determine the experimental performance of the system. Energy consumption data inputs were fed into the thermal model of an office building which was modelled as per draft version of Energy Conservation Building Code (ECBC) India. This was performed in DesignBuilder and EnergyPlus combination for comparative performance over a baseline case. This baseline office case was served with a VRV system. Energy consumption savings and thermal comfort observations were reported over this baseline case of simulation model. A long-term thermal comfort survey based on previous perceptions of comfort from 16 occupants served by each of these systems was also reported for understanding. The EPI as a result of cooling through VRF, DEC and 2SEC is 89, 54 and 55 kWh/m2.yr which comes to 40% energy savings in both evaporative cooling cases. The hours not met were 505, 839 and 848 for VRF, DEC and 2SEC respectively. In terms of comfortable hours, DEC meets setpoints better than 2SEC. However, in the broader context, even with cooler effectiveness of 1, the evaporative cooling system does not have the capacity to meet setpoints. i.e has high unmet hours. If a building owner is interested in providing minimum comfort conditions and is in favorable of adaptive thermal comfort, evaporative cooling system can be installed. DEC can be the first priority as it does not have the complexity of installation like in 2SEC and initial cost is also not as much as 2SEC. However if providing comfort to occupants is the main goal and setpoint requirements are stringent, then evaporative cooling systems –both DEC and 2SEC are not suitable for office buildings where internal loads are very high.

Effectiveness of natural and mechanical ventilative cooling in residential apartments in hot and dry and temperate climates of India (2017)

Devna Vyas, Michael Apte
Abstract: The potential of cooling with natural ventilation and forced ventilation demands attention and scientific study in order to 1) cater to the need of the larger portion of the population; those who cannot afford to air-condition 2) in order to reduce India’s energy consumption and reduce its greenhouse gas emissions due to space cooling demands. Ventilative cooling refers to the use of natural or mechanical ventilation strategies to cool indoor spaces using outdoor air. The most common ventilative cooling technique is the use of increased ventilation airflow rates during cooler outdoor periods, and night ventilation, but other techniques may also be considered. The effectiveness of Ventilative cooling is dependent on the availability of suitable ambient conditions to provide cooling to space. The objective of this study is to evaluate the benefit of harnessing the cooler ambient air to remove heated indoor air by using ventilation. The aim is to enhance indoor temperatures without resorting to more energy intensive methods such as air conditioning. The thesis attempts to provide a scientific basis to architects and building designers in understanding the benefits and limitations of natural and mechanical ventilative cooling in a typical set of residences located in hot and dry and temperate climate. The knowledge can guide designers towards incorporating ventilative cooling strategy as part of the building design when appropriate. The ventilative cooling benefits are calculated primarily using simulation tools. Further, the study also includes results from field measurements for short-period carried out in an apartment building to compare the results with the simulation models. Benefits in indoor air quality due to natural ventilation is not in the scope of this research. It is concluded from the study that adding ventilating cooling using natural ventilation in a typical residential apartment provides 5-43% increase in comfortable hours for two climate zones of India as compared with free running building. Ventilative cooling with mechanical ventilation provides significant comfort benefits (14-25% as compared to ventilative cooling with natural ventilation) and is beneficial to incorporate in residential apartment buildings in two climate zone of India. When compared to mixed mode buildings with no ventilative cooling, ventilative cooling can reduce thermal load of the apartment by 4-14% and 24-34%. While ventilative cooling is more effective in temperate climate, significant benefits can be achieved even in hot and dry climate of India during night periods. A novel method to continuously measure ventilation rate is developed for affordable yet accurate measurements. the measurements reinforced findings from the simulation results that ventilative cooling can provide significant benefits.

Technical potential of integrating evaporative cooling system with mechanical cooling system in Hot & Dry climate for day use office building in India (2017)

Bipinchandra Patel, Rashmin Damle, Michael Apte
Abstract: The aim of this work is to study the technical potential resulting from the integration of evaporative cooling (direct, indirect and combined) with a mechanical cooling system. This work is limited for the small day-use office space in hot and dry climate of India (refer Annexure - A).

For this purpose, an office space (in Ahmedabad) was identified for which access and architectural & air-conditioning drawings and AC system details are available. Envelope, shading, adjacencies, internal gains, operating schedules, ventilation rates are studied. Base Case model was derived with appropriate changes for year-round mechanical cooling. Annual consumption, peak demand, cooling system size are derived for a cooling set point temperature (CSPT) of 25.5°C using simulation software.

Evaporative cooling strategies like direct evaporative cooling (DEC), indirect evaporative cooling (IEC) and their combinations (IDEC) are simulated with and without mechanical cooling system. Ideal evaporative air flow rates (to meet the cooling loads) for integrated system are found out. Effect of keeping DEC switched off during humid months and during morning hours in winter months are studied. Effect of using IEC for three humid months and using DEC in remaining nine months of the year is also studied. Finally, Simulations for potential of sensible heat recovery device is also explored in this study.

Evaporative cooling systems can be integrated with mechanical cooling system in many combinations. For the similar thermal comfort, hybrid system of mechanical cooling with DEC, IEC and IDEC help reduce VRF cooling system size by 29%, 20% and 38% respectively. HVAC energy is also reduced by 17%, 12% and 26% respectively. Similarly peak HVAC power is also reduced by 21%,12% and 27%.

Use of heat recovery device is justified in case of mechanical cooling only. Heat recovery devidce help reduce mechanical coolical cooling system by 31%, HVAC energy by 7% and peak HVAC power by 15%

Lighting Retrofit of CEPT University: Enhancing Visual Comfort and Reducing Energy Consumption (2017)

Abdul Moeed Chaudhary, Prasad Vaidya
Abstract: The thesis is on lighting retrofit of CEPT University located in India. The research aims to reduce energy consumption and enhance visual comfort of the university. The assessment of the spaces included lighting audits, monitoring of lights, schedule of usage, visual comfort surveys and measurement of illuminance levels. At CEPT University, electricity consumption due to artificial lighting is estimated at 32% of the total due to usage of spaces during the night. Health issues like headache, stressed eyes, glare, and low illuminance levels resulted in more than 50% of the occupants taking breaks for eye recovery. This thesis limits the scope to provide retrofit solutions to meet the requirements of NBC and ECBC for studio, classroom, and private office using the UFC recommendation where appropriate. These three space types contribute to 86% of the lighting energy of the campus. Retrofit solutions were proposed to address the issues identified in the audits and surveys, using technologies from a market survey. The proposed solutions included, lamp sources, fixtures, fixture layouts, interior surface modifications, switching and controls, and task lighting where applicable. These solutions were evaluated for light distribution using Relux lighting simulation software and for cost-effectiveness with a simple payback analysis. The energy savings due to the proposed retrofit are 21%, 44% and 42% for studios, classrooms, and private offices, and the simple payback due to is found 9.5, 3.8, 6.8 years respectively. If all rooms of these 3 space types are retrofitted (67 out of 122 spaces on campus) with the solutions identified, it would amount to an annual energy cost saving of INR 178,670 and annual energy saving of 19,852 kWh for an aggregate payback of 8 years.

Team Kill Bill 4.0 Runners up at Divisional Category for Office Building Division (2021)

The SDI is a competition among postgraduate and undergraduate students from Indian institutions to empower the next generation to combat Climate Change in the building sector. The competition invites to innovate for net-zero-energy, water, waste and climate-resilient buildings. SDI is a derivation of the Solar Decathlon competition originally conceived by the US Dept of Energy in 2002. In India, it is organized by the Indian Institute of Human Settlement (IIHS) and sponsored by Indo-US Science and Technology Forum (IUSSTF). Kill Bill 4.O achieved a cost-effective net-zero energy-water solution by integrating the various infrastructural needs of the project with centralized systems provided by the GIFT City while maintaining its individuality. Underground chutes are provided to connect to the central waste management facility along with centralized STP for sewage water treatment. The water demand is reduced at a building level via low flow fixtures and controllers, irrigational strategies and reuse of treated water to achieve a water autonomy of 45%. Monocrystalline solar photovoltaic panels have been integrated on the roof as well as on the South, West and East façades of the building due to the limited availability of land and caters to 100% building energy requirement. Our building façade has been developed as a minimalistic amalgamation of materials to emphasize the vertical garden wall which aims to provide visual comfort for the occupants and visitors alike while also acting as a buffer between indoor and outdoor environment. The North façade has the highest WWR to maximize the diffused daylight inside the workspaces. A UDI of 72% (inclusive of furniture) is achieved with effective window and shading strategies.The proposed Radiant cooling system reduces the HVAC energy consumption by 70% and achieves 100% comfort hours with the addition of IMAC mixed-mode operations and personal comfort systems.

Team 0:0:0 Runners up at Divisional Category in MultiFamily Housing Division(2021)

A net zero energy, multi-family housing project is a relatively less explored area in the building industry. A net zero energy and water design are even more so. Team 0:0:0 from CEPT University upgraded the Savvy multifamily housing project located in Ahmedabad to triple zero design, that has net-zero energy and water, and has minimal waste thrown out from the system. The design process was developed with a data driven, integrated design approach by a multidisciplinary team from building science, architecture, and engineering disciplines along with the technical support of industry partners.

The project was envisaged by the Savvy group of Ahmedabad to fill an important housing gap in the local residential market - compact, affordable 1-bedroom units for the middle-income group.Energy and water use in residential buildings is driven to a large degree by building occupants. Data was gathered regarding the prospective building occupants for this project from multiple sources (e.g., Google search volume trends, publicly available demographic data and a bespoke survey especially designed for this project). The survey (240 respondents) gave us insights into potential conflicts between occupant’s expectations from their personal living environment and the goals of the project. For example, explicit provision has been made in our design proposal to give access to at least one open to sky terrace to all occupants which would have otherwise been used to install a larger PV array. This led to creating a user-oriented design where needs and interest of the occupants are given importance.Most of our interventions are multi-dimensional. For instance, performance evaluation against heat waves helps achieving goals for energy, resilience, and comfort. Prefab construction is an innovative intervention of mass-producing units in reduced time, with architectural and engineering inputs.

With careful considerations to principles of building science, affordability of users, market forces and user's desire to upgrade their lifestyle, a Renewable Energy Service Company (RESCO) model has been adopted for solar photovoltaic systems. The model has also been extended to making active cooling systems accessible to all occupants as a service, which, if purchased and operated individually, would be beyond the financial means of the occupants of the intended income group.

The outcome is a design that housed a total of 530 dwelling units with an EPI of 22.1kWh/m2-yr. The rooftop array helped attain net positive energy target by generating 23.1kWh/m2-yr of energy. Net water is attained by reducing water usage by efficient fixtures, rainwater harvesting and wastewater treatment. The waste generation is limited by reusing the waste for energy production. The resulting design achieved full FSI with an incremental cost of almost Rs. 3.2 crores and an annual operational savings of Rs. 10,560 for every apartment in terms of their electricity bills.

MTech BEP alumni received Transloar Academy internship (2021)

Sandhiya Jayakumar, M. Tech BEP alumni received Transloar Academy internship for the year 2020-21. Transsolar Academy is a one year program with six fellows from different parts of the world. The fellows for the year 2020-2021 were from Colombia, Cameroon, Honduras, Indonesia and India. The three months training includes 400 hours of training on sustainable design by the industry leaders, covering topics on climate responsive design, building physics and human comfort, passive design strategies, visual comfort, building systems and thermal comfort.

MTech BEP student secured the bronze award at ASHRAE RAL (2021)

Ayushi Mishra, M. Tech student from Building Energy Performance program, secured the bronze award at a student competition organized by ASHRAE Region-at-Large (RAL) during Dec 2020 held at cape town (Hosted virtually). She represented ASHRAE’s Western India Chapter (WIC) at the event, which saw the participation of 16 students, representing 14 global chapters of the ASHRAE region. The topic of presentation was 'The Role of Occupant centric sensing and controls in HVAC'. The presentation explained the impact of Occupant behavior on HVAC energy consumption and the factors that influence it. It also discussed the existing codes and standards in that area and the ways to measure occupant behavior. Alternate cheaper and non-intrusive methods of behaviour measurement was one of the key areas of the discussion and an approach to incorporate the measured data into energy simulations was also discussed through cases studies.

To represent WIC at this platform, Ayushi cleared earlier rounds where she competed with nine contenders representing other reputed universities at the chapter level, where she had represented CEPT University. The competition aimed at in-depth understanding and presentation skills focused on heating, ventilating, air conditioning and refrigerating (HVAC&R) topics.

MTech BEP team shortlisted in top 5 in ASHRAE LowDown ShoDown competition (2020)

NetCarbon.IN, an integrated team of architects and engineers, worked together to create a 300,000 square foot, 15 story mixed-use building located in New York City. The challenge required the design of carbon-neutral building that would contain retail space, residential space, and a full-service restaurant. The project started off by climate analysis and design development inferences from the early design tools. Our aim was to enhance natural ventilation, increase exposure to natural light and sustainably source non-toxic material for the occupant's well-being in accordance with the WELL Standards.

The energy team calculated the number of hours wherein the building can operate in naturally ventilated mode, examined potential of radiant heating/cooling system, and worked upon strategy like capitalizing on constant ground temperature through geothermal heat pumps.Shoe box model was built and simulated as per the input parameters listed in ASHRAE 90.1 and ASHRAE 62.1 standards and results were analysed in the Design Builder and Energy Plus software.Inputs from daylight simulation and energy simulation were incorporated to achieve the final architectural design. To achieve the thermal comfort a geothermal heat pump system was coupled with Radiant cooling and was embedded in the floor. To cater to the latent loads and fresh air requirement Energy Recovery Ventilation and Dedicated Outdoor Air System were incorporated.

Priority was given to materials with low embodied carbon and materials that can improve Indoor Air Quality. The final EUI achieved was 82kWh/m2/yr. The renewable team calculated the energy that can be generated by BAPV and BIPV panels at roof and wall surfaces. In order to achieve the target of 4.07 KgCO2e/ft2 /yr. by the year 2030, three possibilities were explored i.e., on-site generation of electricity, on-site carbon sequestration, and demand-side management. For lower carbon emission, demand-side management was considered, by shifting the energy intensive activities such as water pumping, laundry, pre-cooling of office buildings to less carbon-intensive hours. This strategy also reduced the demand cost for the building hence reducing the overall energy cost and payback period. Innovative techniques like a)Algae wall panels for electricity generation and carbon sequestration and b)Piezoelectric tiles for electricity generation were considered.

Thus, final carbon emission achieved for the year 2020 is -0.53kgCO2e/ft2/yr. For the year 2030, the total amount of carbon emission is -0.19kgCO2e/ft2 /yr. and for the year 2050 it is -0.12kgCO2e/ft2/yr.

MTech BEP Team wins at ASHRAE Design Competition (2020)

The MTech BEP team of Shubham Solanki, Vardan Soi, Anmol Mathur and Nikhil Singh Yaduvanshi, has secured 3rd position at the ASHRAE Design Competition in the ‘Integrated Sustainable Building Design’ (ISBD) category. The ASHRAE Student Design Competition recognizes outstanding student design projects, encourages students to become involved in the profession, promotes teamwork and allows students to apply their knowledge of practical design. ISBD is intended for students of mixed disciplines with enough training to work collaboratively on the building, mechanical and electrical design. The participating teams were expected to design an energy-efficient, sustainable project approaching a Zero Net Energy building with minimized energy demands for HVAC and all other technical systems that could be satisfied with locally available and/or building installed Renewable Energy Sources.

MTech BEP, CEPT University Alumni receives a Fully-Funded Ph.D. Position at Concordia University, Canada (2020)

Kartikay Sharma, an alumnus of MTech BEP (2015-17) receives a four year fully-funded PhD position in Canada Excellence Research Chair in Smart, Sustainable and Resilient Communities and Cities, at Concordia University, Montreal. He will be working with Prof. Dr Ursula Eicker, Canada Excellence Research Chair, who specializes in energy efficiency in buildings and sustainable energy supply systems. At Concordia, she is leading a team of energy planners, designers, philosophers, biologists and building engineers to develop integrated strategies for efficient, creative, and accessible zero-carbon cities.

Kartikay would pursue his PhD in Urban building energy modelling (UBEM) with focus on developing a support system to develop an integrated urban data and modelling platform to monitor and optimize energy performance and to plan zero-carbon strategies for cities.

MTech BEP Alumni receives a Fully-Funded Ph.D. Position at Loughborough University, UK. (2020)

Jaydeep Bhadra, an alumnus of MTech BEP (2015-17) receives a four year fully-funded Ph.D. position in Energy Resilience and the Built Environment (ERBE), at the School of Architecture, Building, and Civil Engineering of Loughborough University. He will be working with Prof. Kevin J Lomas, Director, Loughborough, Centre for Doctoral Training in ERBE who specializes Dynamic Thermal Modeling of Buildings, Building Energy and Environment Research, Low-energy Building Consultancy, and Dr. ArashBeizaee, the Academic Manager of ERBE who specializes in Thermal Comfort and Indoor Environmental Quality, Building Performance Modelling and Monitoring, Low Energy Building Services Design, and Data Analytics for Building Energy Research.

He would pursue his Ph.D. in Comfort, Health, and Wellbeing with a major thrust on understanding how Personal Cooling System (PCS) can support the psychological adaptive mechanisms of the occupants of houses to remain comfortable during the household chores. His research will aim to assess the thermal comfort and energy savings potential of PCS devices in different conditions of a household.

The award is jointly funded by the UK Engineering and Physical Sciences Research Council (EPSRC) and Loughborough University.

MTech BEP students won the Merit Award of ‘Architecture at Zero 2020’ (2020)

The students of MTech Building Energy Performance at CEPT University wins Merit Award of ‘Architecture at Zero 2020’. ‘Architecture at Zero’ is a zero net energy design competition open to students and professionals worldwide. The 2020 edition was to create a zero net energy library for the San Benito County Free Library in Hollister, CA. The organizers received 230 entries from 49 countries. The competition was organized by Architecture Pacific Gas and Electric Company (PG&E) and the American Institute of Architects California (AIA CA). CEPT’s team shares Student Category Merit Award under with team from Cankaya Uni, Turkey, and Wroclaw University of Science and Technology, Poland.

CEPT’s team demonstrated a design solution integrating building envelop system with building services such as HVAC, lighting, and building controls. The solution optimized building envelop for its heat transfer and the integrated advanced HVAC and controls systems such as radiant cooling and active chilled beams for thermal comfort. The design solution provides 96% of daylight spaces and integrates Solar Photovoltaic having capabilities to generate approximately 350 MWh per year.

MTech BEP student receives a Funded PhD Position at the University of Colorado, Boulder (2020)

Saranya A, a Student of MTech BEP (2017-19) receives a four year funded PhD position at the Sustainable Buildings and Societies Laboratory (SBS Lab), at the University of Colorado Boulder, US. She will be studying under the guidance of Dr. Wangda Zuo, Associate Professor and Director of SBS Lab, who specializes in Advanced Modeling and Simulation for smart, sustainable, and resilient cities, building-to-grid integration, and Fast Fluid Dynamics (FFD). She would pursue her PhD in Architectural engineering, with a focus on the equation-based, object-oriented modeling approach using Modelica for Connected Cities and Communities.

MTech BEP Student Awarded the BHAVAN Internship 2020 By the Indo-US Science and Technology Forum (2020)

Anmol Mathur, a student of MTech Building Energy Performance program has been awarded the BHAVAN Scholarship to research Urban Energy Modelling at Lawrence Berkeley National Laboratory (LBNL), USA. The Department of Science and Technology, Govt. of India and the Indo-US Science and Technology Forum (IUSSTF) have established a dynamic visitation program between Indian and US institutions and premier US Universities. The Building Energy Efficiency Higher & Advanced Network (BHAVAN) Fellowships and Internships are envisaged to create a sustainable and vibrant linkage between the two nations, as well as build long term Indo-American science and technology relationships.

Research Topic: Developing a pathway towards energy efficiency in Indian cities using Urban Energy Modelling

Organisation: Lawrence Berkeley National Laboratory, California

Abstract: By 2047, India’s rapid urbanisation at 34% will raise the energy demand & carbon emissions by 12 and 3 times respectively (NITI 2015). The Government’s Smart City mission plans an urban renewal and retrofitting program by developing 100 citizen-friendly and sustainable smart cities across the country (MUD India 2015). Optimizing the existing building stock is a key strategy for cities to minimize energy consumption, GHG emissions, mitigating climate change and achieve the Nationally Determined Contributions. Understanding the dynamics of the urban building stock is essential to ensure phase-wise implementation of energy efficiency codes & policies like Energy Conservation Building Code (ECBC), Indian Cooling Action Plan (ICAP) and National Energy Policy. This can be achieved through a data-driven approach to develop specific action plans for different cities. Thus, adopting bottom-up Urban Energy Modelling (UEM) can advance urban and regional analyses, municipal planning processes, implementation of these policies and correlating them to optimize future cities. This research will develop strategies for 100% clean energy in the city of Ahmedabad using the City Building Energy Saver (City BES) tool. Research will be conducted by generating a computer 3D model for 5sqkm of the Central business District of Ahmedabad as a pilot project. The model will be used to develop scenarios of energy consumption and emissions due to rapid urbanisation in the city. An optimized case with implementation of different energy conservation measures at various levels will be presented. Strategies to scale up the model to the entire city will also be explored. The result is envisioned in the form an open web-based platform that is readily accessible by local government, planners, policy makers, residents and other stakeholders. The platform will inform impact of various energy efficiency codes and policy, integration of renewable energy and lifecycle cost benefits along with alternate planning and urban design schemes. This research will be a steppingstone towards creating city-information models for a data driven, efficient and robust planning, management and governance of Indian cities in times to come.

Amravati Design Challenge – Small Scale Residential Development Scenarios (2019)

Anmol Mathur, Shubham Solanki and Vardan Soi, 1styear students in the M. Tech Building Energy Performance program won the 1st place at Amravati Design Challenge - Small Scale Residential Development Scenariosorganised by Andhra Pradesh Capital Region Development Authority (APCRDA). The challenge was to develop a scheme of residential design for five different plot sizes, 4 orientation, and different family types, yet integrated with the principles of Amravati’s culture, vastu& most importantly climate responsiveness.

The designs were strategically developed to meet the IGBC Green homes criteria, attempting 60 points for platinum certification. These homes promise to provide 35% energy savings & 20% water use reduction as compared to a regular house & rigorously followed the ECBC. A predesign analysis suggested the optimal massing to reduce Solar insolation. The analysis showed equal heat gain from walls as with the roof due to the location being closer to the equator.

The envelope had a U-value of 0.7W/m2 & heavy thermal mass with stone cladding on the west & south-east facades. The Window wall ratio was derived through parallel heat flux & Spatial daylight autonomy simulations varying from 15% in the west to 40% in the North. The jail screens were designed in a way to maintain these WWRs & also provide shading cutting of 100% sun with radiations greater than 450W/m2.

Not just energy savings but also the comfort hours according to IMAC thermal comfort model the proposed design provides 30% greater comfort hours indoors.

A continuous shaded terrace with Integrated solar PVs as a pergola charged the house with renewable energy.

These strategies set a new benchmark for High-performance yet affordable houses.

M.Tech BEP student wins competition at Jordan (2019)

Krutikaa Sharma, M. Tech student from Building Energy Performance program, has secured the first place at a student competition organized by ASHRAE Region-at-Large (RAL) during 27-29 Sep 2019 at Jordan. She represented ASHRAE’s Western India Chapter (WIC) at the event, which saw the participation of 17 students, representing 14 global chapters of the ASHRAE region. Kartikaa made a presentation on Indoor Air Quality (IAQ) in healthcare facilities.

The title of her presentation was Indoor Air Quality (IAQ) in Healthcare facilities, where she also explained National and International IAQ standards for healthcare facilities, especially Operation Theatres. The presentation focused on ventilation systems exclusively associated with Operation theatres in hospitals and their respective performances and implications on Indoor Air Quality.

Krutikaa’s presentation explained national and international IAQ standards for healthcare facilities, especially Operation Theatres. To represent WIC at this platform, Krutikaa cleared earlier rounds where she competed with nine contenders representing other reputed universities at the chapter level on 6 Aug 2019, where she had represented CEPT University. The competition aimed at in-depth understanding and presentation skills focused on heating, ventilating, air conditioning and refrigerating (HVAC&R) topics.

M.Tech BEP lead team Kill Bill III enter finals of US DOE Race to Zero Student design competition (2019)

Team Kill Bill from CEPT University, India, Team Kill Bill 3 upgrades the existing multifamily housing scenario in India, transforming it into a net-zero energy, low carbon and resource-efficient solution, catered specifically to the hot-and-humid climate zone prevalent in India. Developed with a data-driven integrated design approach by a multidisciplinary team and technical support of our Industry partners we present ‘Aatral Homes’ (Aatral is Energy in Tamil).

The proposal improved further an existing IGBC rated affordable housing project under the PMAY scheme, on a site based in Avadi – 20 miles from Chennai, Tamil Nadu, India.With careful consideration to the building science principles and affordability carrying out pre-design comfort & energy simulation we developed an optimized building massing having a huge potential for obtaining thermal comfort through natural ventilation. The design was able to reduce the Energy Use Intensity (EUI) by 50% from BAU scenario.

Team Kill Bill III (Left of Table) Krishna Patel, Siddarth Thoudam, Khushbu Bhatt, Niveditha Paulraj, C. H. Yesaswini, Suyashi Srivastava, Kaushik Jayaveeran, Shubham Solanki, Sreejith Jayaram, (Right of table) Vardan Soi, Nikhil Singh Yaduvanshi, Anmol Mathur, Gaurav Vakil, Krutika Sharma, Mahesh Kumar, Mayuri Agrawal, Akshat Gupta, Vismaya Paralkar

The business model of Rooftop solar leasing and Cooling as service were the highlights of the projects which ensured a Net-Positive energy design and providing central air conditioning to the homes using a higher efficiency and reduced capacity of the VRF Cooling system, at affordable prices.

Water efficiency measures coupled with wastewater recycling system reduces water demand by 50%. The design performance is tested for future weather scenarios up to 2025 using climate models.

The outcome was an entire urban design template of 24 such housing blocks on the 4 acres site to achieve 200% FSI. The solution ensures a 78% reduction in utility bills and 50% reduction in water demand from city supply, while keeping the final selling price well within affordability limits of Rs. 20-30 lacs, while keeping intact the developer's profit margin. Kill Bill 3-Report

M.Tech BEP Student awarded the BHAVAN Internship 2019 by the Indo-US Science and Technology Forum (2019)

Research topic: Development of Open source Validated Modelica models for Direct evaporative cooling system.

University: University of Colorado Boulder

ABSTRACT : Increasing income and preference of comfort conditions in India has resulted in a quick increase in energy demand for space cooling. India’s cooling action plan aims at reducing the demand for cooling by 20-25%, refrigerants by 25%-30% and cooling energy by 25%-40% by the year 2037-38. Hence low energy cooling systems such as direct and indirect evaporative coolers are going to be the next alternative to conventional air conditioning in dry climates like India. Hybrid evaporative cooler with controls are progressively developing, yet energy modelers and system designers need modeling capacities that allow them to evaluate energy performance with arbitrary system topology and incorporate efficient controls. This can be attributed to the unavailability of flexible models. The equation based object-oriented Modelica modeling approach can meet such needs.

This paper aims to develop and validate Modelica DEC models. Two versions of the DEC models are developed and implemented in Modelica: one is a lumped model which is used in EnergyPlus and the other is a detailed physics-based model. The lumped model uses efficiency derived from a curve fit equation of the pad. Whereas the physical-based model accounts for mass flow rates, thermal and geometrical characteristics of the cooling pads to compute the heat and mass transfer. The model prediction is then compared to the measured data from literature. The results show that the mean absolute percentage error for the lumped model is 11% and for the physical-based model is 3%. Also, for different materials and pad configurations, the physical-based model has ±2 % error in the performance compared to experimental data from the literature. This model will be a potential contribution to the open source library.

M.Tech BEP Student awarded the BHAVAN Internship 2019 by the Indo-US Science and Technology Forum (2019)

Research Topic: HDR Imaging for an IOT based to lighting and blind controls using a desktop monitor mounted camera

University: Energy Studies in Buildings Laboratory, University of Oregon

Previous research showed that luminance data are much more valuable and reliable in predicting occupant demands and desires for visual environmental control of lighting and facade systems than the ceiling mounted illuminance sensors. Also measuring luminance at eye level is a better proxy for how we perceive light. High Dynamic Range Imaging (HDR) luminance sensors offer a higher spatial resolution signal than traditional illuminance-based photosensors to control overall lighting and façade systems. HDR techniques have been used primarily as diagnostic and predictive tools but have yet to be leveraged as a facade or lighting control signal.

This research examines the historic data set captured from the Firefly MV cameras to determine if the data from the top of the monitor correlate adequately with the Canon HDR data captured from the seated occupant’s perspective. This project also develops a low cost HDR sensor that can be easily positioned and oriented (or can be mounted on desktop) to capture the luminance data of the vertical visual field for lighting and façade controls. This research can help in developing a network of desktop monitor mounted cameras for HDR imaging and controls that can provide an Internet-Of-Things (IOT) based approach towards visual comfort.

MTech BEP Students Won 1st place in ‘The Stellar Façade Design Competition for an IT Park’ (2018)

Anmol Mathur, Shubham Solanki and Vardan Soi, 1st year students in the M. Tech Building Energy Performance program won the 1st place at the Stellar Façade Design Competition for their entry on designing a climate responsive and cost-effective façade design.

The competition was organized by Stellar Ventures (P) Ltd of the Stellar Group which has over 7 million sq. ft. in the National Capital Region of Delhi. The challenge was to provide a facade system for an 11-storied office tower in NOIDA with 4,40,000 square feet of built-up area. The façade system needed to be adaptive, responsive to human needs and climatic conditions, and minimize energy consumption for the building. The designs were judged by Ashok B. Lall, SuneetMohindru and AkshaySethi (Director, Stellar Group) and Akshay Garg (Head Architect, Stellar Group).

The CEPT team created an innovative and aesthetically appealing sustainable design solution that provides visual and thermal comfort, cuts direct sun and is cost effective. According to them, their design was “pleasing, vibrant and adds life to dull and monotonous all glass urban fabric of Delhi NCR”.

They started by analyzing and assessing loads with simulation software (Rhino-Grasshopper-Ladybug and Lightstanza) as well as manual calculations. They used solar angles, masks, radiation maps, as design tools and annual daylight levels, envelope and cooling loads to evaluate their design options. The result was an innovative tensile fabric fin system that was optimized for cooling load daylight and views. The jury found their “twist” appealing and also appreciated the durability and cost effectiveness considerations.

The design solution significantly reduced envelope loads by distributing windows appropriately on the facades, and the fin system cuts 70% direct solar radiation on the windows. They estimated a reduction of 40% for lighting energy and 20% for cooling energy.

Jeffery Cook travel Scholarship (2018)

Maaz Barin Dixit, a student of M.Tech. BEP received Jeffery Cook's student travel scholarship to present the paper titled "Performance Evaluation Of An Energy Efficient Educational Building In India" at Passive and Low Energy Architecture (PLEA) conference, Yasumoto International academic park, Hong Kong, held from 10-12th December 2018. The scholarship was provided by the Society of Building Science Educators (SBSE).

M.Tech BEP lead team Kill Bill II enter finals of US DOE Race to Zero Student design competition (2018)

Learn Unplugged’ is a proposed Kendriya Vidyalaya under the central Government of India located at Jodhpur in the Indian state of Rajasthan. The total site area and the built-up area of the school campus are 6 acres and 3538 m2 respectively. The design is an integration of built environment with playscapes, urban farming, water conservation, biodiversity park, Environment and Building-as-a-Learning-Aid (E-BaLA) elements and renewable energy through photo-voltaic systems with a focus of meeting the Living Building Challenge (LBC) standards and Advanced Energy Design Guide for K-12 school buildings. The overall design of the project, constructability, feasibility, energy reduction strategies- both active and passive, landscape features, E-BaLA concepts were integrated with two main goals:
Achieve net positive energy - the project has achieved 11% beyond net-zero with 11% returning back to the power grid.
Achieve comfort and health standards beyond prescriptive methods - the project has managed to lessen unmet hours to 189, which is well below 300 hours (threshold as per Energy code in India).

Team Kill Bill II, from left (back row) Abimanyu Setia, Chetan Sodaye, Vijay M B, Utkarsh Mathur, Shoumik Desai, Sahil Verma, Pratik Khatri, (front row) Jagadeesh Gorle, Yashima Jain, Amanda Th. Sanchi Pathella, Garima Kamra, Saranya A, Nidhi Rai Jain, and Ankit Debnath

All of these have been achieved with a EUI of 14.04 kBtu/ft2/year. Classroom spaces are cooled by evaporative cooling and most other spaces by VRF systems. Natural ventilation and HRV are the modes of fresh air supply for these cooling systems respectively. All the spaces have a Daylight Autonomy of >90% for a threshold of 300lux. Electric lighting, though not necessary as per the working hours of this school, has also been proposed to achieve 300lux with an LPD of 4.5W/m2. EPD of 4.9W/m2 has also been achieved along with this. Efficient usage of water through low flow fixtures and root zone treatment are strategies used as part of water efficiency. Native and adaptive species of landscape have been cautiously chosen in order to integrate well with water efficiency and overall vegetative cover. Compressed Stabilized Earth Blocks (CSEB), that can be made on-site are proposed for construction and hence reduces embodied energy and carbon footprint. The total capital cost of the project is 35% higher and the operation cost is 28% lower with a return on investment of 11 years.

KiLL Bill 2-Report

M.Tech BEP Student awarded the BHAVAN Internship 2018 by the Indo-US Science and Technology Forum (2018)

Research topic - Overall Thermal Transfer Value of Building Envelope

University - Arizona State University

Abstract: There is an ever-increasing demand of electricity in the residential sector of India which must be controlled. In this research work, we have proposed a simplified tool as compared to sophisticated software which can calculate comfort hours in naturally ventilated residences. This tool can evaluate the thermal performance of the building envelope with the help of Overall Thermal Transfer Value (OTTV). Higher thermal performance of building envelope will result in reduction of energy usage by the mechanical means of achieving thermal comfort. This tool has been used to perform parametric analysis for three major climate zones of India. A relationship between OTTV and comfort hours has been established through linear regression. Using these equations OTTV can be standardized to achieve maximum comfort in naturally ventilated residences. The standardized OTTV can be implemented in the energy code of India as a performance method for building envelope.

M.Tech BEP lead team Kill Bill wins US DOE Race to Zero Student design competition (2017)

CEPT’s Team KILL BILL won the 1st place trophy in the Urban Single Family Housing category of US Department of Energy’s “Race to Zero” Competition. Team Kill Bill was led by students in the M. Tech. Building Energy Performance program, with a goal to “kill” the electricity “bill” (shortage) in India. Fifteen CEPT students from the Faculties of Technology, Architecture and Planning made up the team. They replicated a real-life Integrated Design Process with specific roles for team members, seen internationally for high performance buildings but rare in India. Members of the Faculty of Technology mentored the team in an elective course.

Team Kill Bill, from left (back row) Vasudha Sunger, Arihant Jain, Nikhilesh Singh Bisht, Arjun Desai, Akash Ghadiyali, Sahil Priyadarshi Archanaa M, (front row) Kurva Dhonde, Pooja Mundhe, Vertika Srivastav, Aakanksha Khare, Mansi Parikh, Sandhiya Jayakumar, Shravya Reddy and (absent) Sumit Rawat

Over five months, they designed, prepared working drawings that included MEP systems, demonstrated performance with simulations, estimated costs and developed financing strategies. They designed a marketable house in Jaipur that is zero energy, zero water, gets WHO levels of air quality despite ambient pollution, and all this at a debt-to-income ratio that bankers found acceptable for their target market. Team KILL BILL’s work was commended by the jury for excelling under all categories of evaluation in the competition.

KILL BILL was one of the 39 participating teams, and the only team from outside the Americas that made to win the competition. They presented their design to a jury of industry leaders at the National Renewable Energy Laboratory in the USA.

Kill Bill 1-Report

M.Tech BEP student awarded the BHAVAN internship 2016 by the Indo-US Science and Technology Forum (2016)

Research topic- Developing Baseline Benchmark models for Energy Consumption

University - Centre for Sustainable Building Research, University of Minnesot

The focus of the study was to develop benchmark models for energy consumption for various building types and functions for the Indian context. Various parametric combinations viz., shading depths, orientation, wall assembly, daylighting and window to wall ratio were modeled and simulated. This research included modeling and designing framework for simulation runs where three approaches will be dealt with, viz., whole-building simulation, assets and operation and lastly the system benchmarking. The outcome of this research was an Excel-based simple tool that was easy to use for an Architect/ Owner in the pre-design or even the programming phase where they can estimate the EPI through minimal inputs

M.Tech BEP student selected for ECOSPERITY Young Leader’s Dialogue 2015, Singapore (2015)

Three students from CEPT University were selected for Ecosperity Young Leader’s Dialogue (EYLD) 2015 in Singapore on 18th & 19th September 2015 in Singapore, namely: Mohit Kapoor (Master of Urban & Regional Planning, MURP); Maaz Dixit (Master of Technology in Building Energy Performance, M. Tech); Kaushik Kumar (Master of Architecture, M. Arch). Ecosperity Young Leader’s Dialogue (EYLD) 2015 is organized by the National University of Singapore (NUS), School of Design & Environment (SDE) and Institute of Real Estate Studies (IRES). EYLD is a partner event of Ecosperity 2015 organized by Temasek Holdings. The objective of EYLD 2015 which is an annual forum that connects leaders of tomorrow with industry experts to dissect, discuss, and discover sustainable urban planning strategies. More than 140 students from 15 countries with various academic backgrounds such as urban planning, architecture, environmentalists, urban designers, etc. were selected for EYLD 2015. Discussion Topics 1. Are developing countries equally responsible for sustainable development as developed countries? 2. Should sustainable urban planning prioritize society over the natural environment? 3. Moving forward, what are some sustainable urban planning strategies and technologies that should be explored further? Ecosperity is a series of sustainability-focused conferences presented by Singapore-based investment company Temasek in Singapore. The conference brings together CEOs, innovators, policy makers and thought leaders from around the world to explore the latest issues on sustainable growth. The name “Ecosperity” combines ecology with prosperity – embodying the belief that growth can take place in a sustainable manner. This year, the 2015 conference will focus on urbanization and the challenges and opportunities arising from developing smart and sustainable cities. https://www.youtube.com/watch?v=qXfuvbMltE4


Thermal comfort and Energy performance assessment for Faculty of Architecture building at CEPT post restoration by Archie Parakh
Operational, economic, and environmental impact assessment of existing DX-split systems in Hot and Dry climate by Sammit Pancholi
Evaluating the energy saving potential through occupant interaction by Amanda Santiyago
Effect of Relative humidity on Adaptive thermal comfort by Akshay Garg

Assessing the Impact of Sizing Methods on the Performance of Radiant Cooling Systems by Het Modi

Achieving Net-Zero Energy in High Rise Office Building in India and Its Cost Implications by Gaurav Vakil
Evaluation of Existing Glare Metrics for Indian Context by Kaushik Jayaveeran
Identification and Validation of Simulation Methodology to predict daylight performance of Perforated Screen (Jaali) by Khushbu Bhatt
Impact of Room Air Conditioner Outdoor Unit Placement Configuration on Energy Efficiency by Krishna Patel
Assessing the indoor air quality in an intensive care unit of a hospital in a metropolitan city. by Krutikaa Sharma
Development of smart rule-based control algorithms for solid desiccant systems in Warm and Humid regions of India by Mahesh Jayachander
Enhancing Day Lighting For a Coaching Institute by Giving Retrofit Solutions Using a Luminance-Based Illuminance Approach. by Mayuri Agrawal
Developing Solutions for Limiting Energy Consumption of Buildings Due To Socio-Economic, Technological and Floor Space Evolutions by Nikhil Singh Yaduvanshi
Study of Energy Usage and Thermal comfort in Affordable housing in Chennai by Niveditha Paulraj
Evaluating the Scope of Energy Reduction by Cooling the Office Spaces Using Low Energy Cooling Systems by Shubham Solanki
Automation and Operational Optimization of Venetian Blinds Based Façade for User Comfort: A Simulation-Based Framework by Sreejith Jayaram
Tree Shading Factor as Input for Thermal Models through Hemispherical Photography by Suyashi Srivastava
Adaptive Façade Design for Users’ Visual Comfort by Thoudam Siddarth
Estimating the Effect of Air Infiltration Rate on RETV Values: On-Site Measurements and Energy Simulations by Utkarsh Mathur
Spatial & Temporal Thermal Maps for Naturally ventilated Indoor space: Developing a methodology using currently available tools to plot Operative Temperature for naturally ventilated indoor spaces by Vardan Soi
Hygrothermal Performance of Lime Plastered Naturally Ventilated Spaces by
Vismaya Paralkar
Thermal comfort and Energy performance assessment for Faculty of Architecture building at CEPT post restoration by Archie Parakh
Operational, economic, and environmental impact assessment of existing DX-split systems in Hot and Dry climate by Sammit Pancholi
Evaluating the energy saving potential through occupant interaction by Amanda Santiyago
Effect of Relative humidity on Adaptive thermal comfort by Akshay Garg

Assessing the Impact of Sizing Methods on the Performance of Radiant Cooling Systems by Het Modi

Achieving Net-Zero Energy in High Rise Office Building in India and Its Cost Implications by Gaurav Vakil
Evaluation of Existing Glare Metrics for Indian Context by Kaushik Jayaveeran
Identification and Validation of Simulation Methodology to predict daylight performance of Perforated Screen (Jaali) by Khushbu Bhatt
Impact of Room Air Conditioner Outdoor Unit Placement Configuration on Energy Efficiency by Krishna Patel
Assessing the indoor air quality in an intensive care unit of a hospital in a metropolitan city. by Krutikaa Sharma
Development of smart rule-based control algorithms for solid desiccant systems in Warm and Humid regions of India by Mahesh Jayachander
Enhancing Day Lighting For a Coaching Institute by Giving Retrofit Solutions Using a Luminance-Based Illuminance Approach. by Mayuri Agrawal
Developing Solutions for Limiting Energy Consumption of Buildings Due To Socio-Economic, Technological and Floor Space Evolutions by Nikhil Singh Yaduvanshi
Study of Energy Usage and Thermal comfort in Affordable housing in Chennai by Niveditha Paulraj
Evaluating the Scope of Energy Reduction by Cooling the Office Spaces Using Low Energy Cooling Systems by Shubham Solanki
Automation and Operational Optimization of Venetian Blinds Based Façade for User Comfort: A Simulation-Based Framework by Sreejith Jayaram
Tree Shading Factor as Input for Thermal Models through Hemispherical Photography by Suyashi Srivastava
Adaptive Façade Design for Users’ Visual Comfort by Thoudam Siddarth
Estimating the Effect of Air Infiltration Rate on RETV Values: On-Site Measurements and Energy Simulations by Utkarsh Mathur
Spatial & Temporal Thermal Maps for Naturally ventilated Indoor space: Developing a methodology using currently available tools to plot Operative Temperature for naturally ventilated indoor spaces by Vardan Soi
Hygrothermal Performance of Lime Plastered Naturally Ventilated Spaces by
Vismaya Paralkar

Supported by:

Ministry of New and Renewable Energy Govt. of India, Gujarat Energy Development Agency, U.S. Agency for International Development iNDEXTb (Industrial Extension Bureau) Govt. of Gujarat, Shakti Sustainable Energy Foundation, New Delhi