Energy conservation and indoor air pollution

Abstract

Energy-conservation measures for buildings work partly by reducing air exchange ( v) between buildings and their surroundings, resulting in greater retention of pollutants emitted indoors by combustion and other sources. For example, if v is reduced 4-fold, pilot-light pollutant contribution will quadruple (perhaps rising from ≅5 mg/m 3 to ≅20 mg/m 3 for carbon-monoxide). A calculation shows that it might take 4 1 2 h for CO levels to decline below the EPA one-hour ambient standard after only 1 h of oven use in a small kitchen when v = 1 4 air change/h (ach) but less than 1 2 h when v = 1 ach. We present a model that accounts for the reduced heating system operating requirement permitted by energy conservation by assuming that indoor pollutant levels are linear in v This model predicts that when v is reduced 4-fold, heating system pollutant contributions can still rise up to 3-fold, depending upon building characteristics and the extent of increased insulation. Thus precautions are clearly necessary when tightening building envelopes. At a minimum, pilot lights should be eliminated and effective kitchen ventilation systems installed.