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Modeling the IAQ Impact of HH1 Interventions in Inner-City Housing.

pdf icon Modeling the IAQ Impact of HH1 Interventions in Inner-City Housing. (2605 K)
Emmerich, S. J.; Howard-Reed, C.; Gupte, A.

NISTIR 7212; 99 p. March 2005.


Department of Housing and Urban Development, Washington, DC


housing; impact; exposure; ventilation; residential buildings; contaminants; simulations; occupants; zone models; carbon dioxide; water vapor; nitrogen dioxide; carbon monoxide; particles; radon; kitchens; bathrooms; living rooms; stairways; dining rooms


The U.S. Department of Housing and Urban Development (HUD) has identified a need to improve urban housing conditions to protect children's health through its Healthy Homes Initiative (HHI). One critical area within this program is indoor air quality (IAQ), for example, inadequate ventilation, moisture, combustion by-products, etc. and the identification of effective intervention strategies to address these issues. To evaluate the impact of different interventions on indoor contaminant concentrations and occupant exposures, a simulation study was conducted using the multizone airflow and contaminant dispersal model CONTAM. This study modeled the exposures of a family of five to concentrations of carbon dioxide, carbon monoxide, nitrogen dioxide, water vapor, 0.3 /lm to 10 /lm particles, radon, and volatile organic compounds in a three-story townhouse. To investigate the impacts of environmental conditions, the townhouse was modeled with weather conditions from all four seasons in Boston, MA, Miami, FL, and Seattle, WA. The model included outdoor and indoor sources of the contaminants as well as adsorption and deposition loss mechanisms. CONTAM predicted ventilation rates, contaminant concentrations and occupant exposures for a baseline case and eight different interventions in each city/season combination. The interventions included venting an otherwise unvented space heater, replacement of a faulty stove, upgrading a furnace filter, installation of air conditioning, operation of kitchen and bathroom exhaust fans, ceasing the practice of using a gas oven to heat the house, tightening the house's envelope, and installation of mechanical ventilation. Intervention strategies were compared on an individual basis and a small sub-set of interventions were considered to demonstrate an intervention ranking system for identifying the best strategy. The key parameter utilized in evaluating the interventions is the concentration relative to the baseline rather than comparison of absolute concentrations to guideline values. Overall, a combination of mechanical ventilation, local exhaust, and an improved air filter was most effective for reducing the largest number of contaminants in the study.