The impact of reduced ventilation on indoor air quality in residential buildings

TLDR: In this paper, a research program was conducted to determine the extent to which low ventilation rates are compatible with good indoor air quality, and the results of this program suggest that further studies, designed to include a broader range of infiltration rates ad occupancy conditions, are needed before establishing energy-efficient infiltration standards for residential buildings.

Abstract: Rising energy prices have generated a national incentive to reduce ventilation rates in buildings and thereby lower heating and cooling costs. One of the ramifications of reducing ventilation is that indoor air contaminants build up and pose a health risk to occupants. A research program being conducted to determine the extent to which low ventilation rates are compatible with good indoor air quality is described. Overall indoor air quality is influenced by air-exchange rates, types of appliances and building materials used, and occupant activities. From the numerous indoor air pollutants studied, four (carbon monoxide and nitrogen dioxide from gas appliances; formaldehyde from particle-board, plywood, urea formaldehyde foam insulation, and gas appliances; and radon from soil, building materials, and ground water) are receiving considerable attention in the context of potential health risks associated with energy conservation. Field monitoring studies in energy-efficient residential buildings have demonstrated that, in some cases, these indoor-generated pollutants exceed outdoor air-quality standards in houses having air-exchange rates of less than 0.5 air changes per hour. The results of our research suggest that further studies, designed to include a broader range of infiltration rates ad occupancy conditions, are needed before establishing energy-efficient infiltration standards for residential buildings.