Energy performance of room air-conditioners and ceiling fans in relation to thermal comfort (2023)
Abstract: Studies show that people can tolerate elevated temperatures in the presence of appreciable air movement (e.g., by using ceiling fans). This results space cooling energy savings by reducing the use of air-conditioners and extending their set point
temperature (Tset). However, there is little empirical evidence from India on the energy savings from the use of ceiling fans with air-conditioners. To address this gap, we analysed the energy performance of room air-conditioners (RACs) with both fixed speed compressors and inverter technology at different set point temperatures (Tset) and ceiling fans at different Fan Speed Settings (FSSs) in relation to thermal comfort conditions according to the Indian Model for Adaptive Comfort-Residential (IMAC-R) in 15 residential mixed-mode buildings (MMBs). The study showed that using high FSSs with RACs resulted in unnecessary energy consumption. Compared with the mandatory default Tset of 24°C in the Indian RACs, the results showed that at all FSSs, Tset at 28 and 30°C maintained thermal comfort conditions, i.e., the indoor air temperature (Tin) was between the neutral operative temperature (Tneu) and lower 80% thermal comfort band according to IMAC-R and resulted in mean RAC energy savings 44 and 67%, respectively. Furthermore, at different Tset, RACs with inverter technology consumed 34-68% less energy than fixed speed compressors.
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