Indoor air quality and the variable-air-volume bypass filtration system: Chamber experiment

Two series of experiments were performed in an ail aluminum chamber under controlled conditions to investigate whether the variable-air-volume/bypass filtration system (VAV/BPFS) reduces indoor air pollutant concentrations relative to a conventional variable-air-volume (VAV) system. Twelve short-term experiments (100 min) were performed for each ventilation system using indoor sources and one energy load. Also, twelve long-term experiments (240 min) were performed with the VAV/BPFS and conventional VAV system using indoor air pollution sources emitting intermittently and energy load increasing in a stepwise process. Cigarettes and deodorants were used to simulate activities in the chamber. Four energy loads (400, 800, 1200, and 1900 W) were used to simulate the presence of occupants in the chamber. Results show that, under controlled experimental conditions, the difference between VAV/BPFS system acid VAV system in reducing indoor air pollutant concentration is statistically significant. The particulate matter VAV/BPFS total effective removal rate was 50% higher than the corresponding VAV PM total effective removal rate. Also, the VAV/BPFS total volatile organic compound total effective removal rate was 20% higher than that of the VAV system. These chamber results indicate that the VAV/BPFS system is a promising alternative to the conventional VAV system because, under the conditions tested, it is capable of reducing and maintaining good indoor air quality and decreasing outdoor supply air rate.