EPA Science Inventory

Effects of Climate Change on residential indoor-outdoor Air Exchange


Ilacqua, V., J. Dawson, M. Breen, S. Singer, AND A. Berg. Effects of Climate Change on residential indoor-outdoor Air Exchange. Presented at Indoor Air 2014, Hong Kong, HONG KONG, July 07 - 12, 2014.


INTRODUCTION: Climate change is expected to increase the mean and peak ambient temperatures, and perhaps wind patterns and intensity, while indoor environments will remain within the range of human thermal comfort. As passive air exchange through infiltration is partly driven by indoor/outdoor temperature differences, even small changes in ambient temperature can theoretically modify such differences considerably and, as a result, alter patterns of exposures to both indoor and outdoor pollutants. METHODS: We calculated changes in air fluxes through infiltration for prototypical detached homes in 9 metropolitan areas in the US (Atlanta, Boston, Chicago, Houston, Los Angeles, Minneapolis, New York, Phoenix, Seattle) from the 1970-2000 reference period to the mid-century (2040-2070) period. The LBNL model of infiltration was used in combination with climate data from 8 regionally downscaled climate models. RESULTS: Averaged over all study locations, seasons, and climate models, air exchange through infiltration would decrease by approximately 5%, varying from -7% for Boston, to -2% for Phoenix. Mean between-model uncertainty was about 8%. The range of predicted changes for specific months and models is -14 to +25%. While infiltration is projected to decrease overall, increased infiltration is predicted, within the range of model uncertainty, during the summer months, up to 20-30% for Atlanta and Houston. Seasonal and daily variability in infiltration, as indicated by its standard deviation, is expected to increase, particularly during the summer months. As a result of generally lower infiltration rates, exposure to indoor sources may be expected to rise, especially for less reactive indoor species (such as Radon), for which exposure would increase by approximately the same relative amount as infiltration decreases. CONCLUSIONS: Diminished air exchange in future climate scenarios may be expected to increase exposure to indoor sources of air pollution, unless these ventilation reductions are otherwise compensated. Exposure to ambient air pollution, conversely, would generally diminish, partially countering the effect of the climate change penalty on ambient air pollution, although exposures increases during summer months should be considered.


The purpose of this analysis is to understand the impact of climate change on residential exposure to indoor and outdoor sources of air pollution. This information can be used to inform guidelines for climate change adaptation, and exposure and risk modeling for future scenarios.

Record Details:

Completion Date: 02/20/2014
Record Last Revised: 02/20/2014
Record Created: 02/20/2014
Record Released: 02/20/2014
OMB Category: Other
Record ID: 269259