Performance of an earth-air heat exchanger (EAHE) in a heat recovery ventilation for residential buildings in severe cold regions

The prolonged duration of winter season and the occurrence of extreme low temperatures present significant challenges when implementing mechanical ventilation systems in severe cold regions. These challenges encompass substantial requirements for heating supply air and frequent operations for defrosting. Heat stored in the ground has the potential to be harnessed for pre-conditioning supply air through the utilization of an earth-air heat exchanger (EAHE). This study focuses on evaluating the heating performance of the EAHE when integrated into a heat recovery ventilation system. The energy model of a case building in Harbin and the proposed ventilation system were simulated in IDA ICE. The results show that as the outdoor temperature drops, the proportion of heat supplied by EAHE increases, leading to a decrease in reliance on reheater to heat supply air. This underscores the advantages of applying EAHE to preheat fresh air in colder climates.