Journal Papers

Journal: Energies, Volume 16, Issue 19

Authors: Sriraj Gokarakonda, Christoph Van Treeck, Rajan Rawal, Stefan Thomas

Abstract: Studies show that people can tolerate elevated temperatures in the presence of appreciable air movement (e.g., from using ceiling

fans). This minimises the use of air-conditioners and extends their set-point temperature (Tset), resulting in energy savings in space cooling. However, there is little empirical evidence on the energy savings from using ceiling fans with Room Air-Conditioners (RACs). To address this gap, we analysed the energy performance of RACs with both fixed-speed compressors and inverter technology at different set-point temperatures and ceiling fan speed settings in 15 residential Mixed-Mode Buildings (MMBs) in India. Thermal comfort conditions (as predicted by the Indian Model for Adaptive Comfort-Residential (IMAC-R)) with minimum energy consumption were maintained at a set-point temperature (Tset) of 28 and 30 ◦C and a fan speed setting of one. Compared with a Tset of 24 ◦C, a Tset of 28 and 30 ◦C resulted in energy savings of 44 and 67%, respectively. With the use of RACs, a configuration with a minimum fan speed was satisfactory for an optimal use of energy and for maintaining the conditions of thermal comfort. In addition, RACs with inverter technology used 34–68% less energy than fixed-speed compressors. With the rising use of RACs, particularly in tropical regions, the study’s outcomes offer a significant potential for reducing space-cooling energy consumption and the resultant greenhouse gas (GHG) emissions.

Keywords: room air-conditioners; ceiling fans; set-point temperature; thermal comfort; user behaviour; sensors and monitoring