Conference Papers

Rapid urbanization, rising per capita income and a warming climate are significantly increasing the burden on the electricity grid throughout India(Rawal and Shukla, 2014). The combined use of natural ventilation (NV) and mechanical cooling (MC) systems is a potential solution to provide cooling and thermal comfort

to building occupants. Mixed-mode (MM) buildings use NV and MC to provide a comfortable environment for the occupants. Past studies have established that many Indian residences operate in temporal and spatial MM. Existing algorithms used in MM buildings to changeover between NV and MC modes are unsophisticated often leading to inefficient operation. In most cases, the changeover algorithm determines operation mode based on a predefined temperature or based on the  occupancy schedule. This paper assesses the benefits  of sophisticated changeover control algorithms in a MM residential building. The paper first develops two control algorithms, with varying degrees of complexity, suitable for mixed-mode residential buildings. Further, the benefits of the developed control algorithms are assessed for four climate zones of India using the dynamic thermal simulation model. This paper uses the Functional Mock-up Interface (FMI) to couple Modelica and EnergyPlus as well as to exchange data for co-simulation. The results demonstrate that there is a positive comfort benefit with 76% to 98%lesser uncomfortable hours and 6% to 24% energy savings for the developed algorithms compared to the reference in the 4 climates zones.