Experimental study of exhaust air transfer ratio in a rotary heat recovery ventilation unit with automatic leakage control

Air leakage in a rotary heat recovery device in air handling unit (AHU) was studied by a laboratory experiment. The experiment tested a commercial AHU with rotary heat recovery and equipped with various leakage control techniques, e.g. Automatic Leakage Control (ALCTM), rotor speed control (RSC) and purge sector, etc. In the test, exhaust air transfer ratio (EATR ) of the AHU was measured by tracer gas method at two levels of airflow rates in both constant airflow and constant pressure operation modes of the test AHU.