An experimental study on how the difference between the test setups specified in JIS B 8628 and JIS B 8639 affects the performance values of energy recovery ventilators

JIS B 8628, “Air-to-air heat and energy exchanger and ventilators” provides standards for evaluating the performance of the energy recovery ventilators. JIS B 8628 was established in 2000, and revised in 2003. In 2017, JIS B 8628 was revised furthermore to ensure consistency with ISO 16494, which was established in 2014. For that purpose, the two room setup and the ducted setup, which are prescribed in ISO 16494 with specified pressure conditions at inlet and outlet of energy recovery ventilators for the airflow test, the tracer gas test and the thermal performance test, were added in JIS B 8628 (2017). In Japan, either the two room setup or the ducted setup is being used by manufacturers to determine the performance values, which are referred to when the compliance of total building energy performance to the Building Energy Efficiency Act is claimed. However, no studies have yet focused on the difference of the test results between the two room setup and the ducted setup. In this study, authors applied those setups and the test setup prescribed in JIS B 8628 (2003) to four energy recovery ventilators and compared their results. As for the airflow-static pressure characteristics, the curves obtained by the three test setups generally correspond to each other, except for the curves for the air exhaust line obtained by JIS B 8628 (2003). The unit exhaust air transfer ratio values obtained by the ducted setup and JIS B 8628 (2003) tend to be greater than those by the two room setup. As for the thermal performance represented by the total effectiveness, differences among the three test setups can be observed when there is a difference of the unit exhaust air transfer ratio and/or the ratio of the supply airflow rate to the return airflow rate.