Abstract
This paper describes a study on the performance evaluation of a hybrid ventilation system with a heat exchanger. This system has two passive stacks and a heat exchange unit, which includes a heat exchange element, a supply fan, an exhaust fan and a bypass route with a damper. In order to evaluate the system performance, the experiments using a full-scale test house and the numerical simulations have been performed in winter and mid seasons. The ventilation rate and the heat recovery rate under the various conditions of the fan and the damper operation were measured. The results of the experiments are as follows. 1) The leakage in heat exchanger is very small, but the leakage rate when only exhaust fan is used is larger than another condition. 2) In case of the passive ventilation, the ventilation airflow rate is insufficient, and the reversal flow in the supply duct occurs. 3) When the supply fan is not operated in winter, the ventilation airflow rate to the 2nd floor rooms is insufficient. 4) When either the supply fan or the exhaust fan is operated, the ventilation airflow rate is more than 0.5 times per hour.
