Design, Efficiency and Recovered Energy of an Air-to-Air Energy Recovery System for Building Applications in Hot-Humid Climate

Recently, concerns on energy consumption and air quality in buildings have significantly increased. Hence, a system namely air-to-air energy recovery has been introduced to overcome this problem. It functions to pre-heat and/or pre-cool the incoming air by using the outgoing air and simultaneously provides healthy fresh air to indoor spaces. The application of this system has widely been used in countries that experience cold climates. However, only a few studies present scientific works pertaining to hot-humid climate zone in open literature. To close this gap, thus this study presents a work on an air-to-air energy recovery system for building applications in hot-humid climate. The objective of this study was to evaluate the efficiency and recovered energy of the system. Experimental investigations were conducted under controlled conditions in Energy and IEQ Testing Unit located in School of Industrial Technology, Universiti Sains Malaysia. Tests were carried out under different airflow rates ranged from 1.0 to 3.0 m/s and intake air temperature of 31C, 35C and 40C. The efficiency and recovered energy of the system were calculated and evaluated by adopting calculation method by ASHRAE Standard. The efficiency of this system ranged from 45 to 85 % and the highest recovered energy of 17.5 kW was achieved at 1.0 m/s and 31C. From these results, it was found that the efficiency decreased and in contrast the recovered energy increased with increasing airflow rates.