Saving Energy Costs by Combining Air-Conditioning and Air-Circulation using CFD to Achieve Thermal Comfort in the Building

Abstract

In developed countries, a significant increase in energy consumption was seen in these several years due to the growing demand of HVAC system to achieve thermal comfort in the building environment. High energy consumption of HVAC system has been a major issue for buildings around us. ISO 7730 and ASHRAE Standard 55 stated that greater air flow is able to offset the increase of air temperature by lowering the chilled water temperature. Appropriate air speed and air temperature should be determined without affecting the thermal comfort of building occupants. The aim of the study is to investigate possible energy saving and cost savings in building with higher air temperature and greater air flow using CFD simulation without affecting the thermal comfort of building occupants. Different case studies were carried out to determine the ideal air speed and air temperature in different room models. PMV and PPD index were used as thermal satisfaction indicators to determine the thermal comfort of occupants in different indoor conditions. Experimental and numerical results were analyzed and ideal conditions were proposed based on the results. Potential energy savings up to 47.27% and annual saving of RM 4116.36 were obtained through the studies.