Effectiveness of a heat recovery ventilator, an outdoor air intake damper and an electrostatic particulate filter at controlling indoor air quality in residential buildings.

A preliminary study of the potential for using central forced-air heating and cooling system modifications to control indoor air quality (IAQ) in residential buildings was performed. The main objective was to provide insight into the potential of three IAQ control options to mitigate residential IAQ problems, the pollutant sources the controls are most likely to impact, and the potential limitations of the controls. Another important objective was to identify key issues related to the use of multizone models to study residential IAQ and to identify areas for follow-up work. The multizone airflow and pollutant transport program CONTAM93 (1) was used to simulate pollutant concentrations due to a variety of sources in eight houses with typical HVAC systems under different weather conditions. The simulations were repeated after modifying the systems with three IAQ control technologies - an electrostatic particulate filter, a heat recovery ventilator (HRV), and an outdoor air intake damper (OAID) on the forced-air system return. Although the system modifications reduced pollutant concentrations in the houses for some cases, the HRV and OAID increased pollutant concentrations in certain situations involving a combination of weak indoor sources, high outdoor concentrations, and indoor pollutant removal mechanisms. Also, limited system run-time during mild weather was identified as a limitation of IAQ controls that operate in conjunction with forced-air systems. Recommendations for future research include: simulation of other buildings, pollutants, and IAQ control technologies; model validation; sensitivity analysis; and development of a database of important model inputs.