The combination of earth-to-air heat exchanger (EAHE) and phase change material (PCM) for indoor thermal environment regulation

Abstract

The research and application of energy-saving technologies in buildings is receiving increasing attention. Phase change materials (PCM) is an effective passive cooling technology in the regulation of indoor thermal environment. However, in hot-summer and cold-winter regions, the high ambient air temperature makes it difficult to reduce PCM temperature to the phase change temperature in summer. Earth-to-air heat exchanger (EAHE), as an effective energy-saving ventilation technology, in combination with PCM can improve indoor thermal comfort. We performed full-scale experiments to investigate the combination of EAHE and PCM for indoor thermal environment regulation in a typical hot-summer and cold-winter region of China. After 24 hours of continuous operation in summer, variations in ambient and EAHE outlet air temperature range from 28.50 to 44.52 °C and from 22.78 to 24.78 °C respectively. EAHE can effectively precool fresh air, and its average cooling capacity and coefficient of performance (COP) are 1823.03 W and 16.6. The combination of EAHE and PCM has positive impacts on the regulation of indoor thermal environment. The indoor air temperature is in the 22-28 °C range for 69.0 % of the 24 h, and peak indoor air temperature is 31.14 °C. The hybrid system has a TDR of 0.84.