Air and Pollutant Transport from Attached Garages to Residential Living Spaces.
Air and Pollutant Transport from Attached Garages to
Residential Living Spaces.
(682 K)
Emmerich, S. J.; Gorfain, J. E.; Huang, M.; Howard-Reed,
C.
NISTIR 7072; 25 p. December 2003.
Available from:
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Website: http://www.ntis.gov
Keywords:
garages; residential buildings; pollution; house-garage
interface; attached garage; blower door; indoor air
quality; living space; pollutant
Abstract:
NIST is conducting a study on the indoor air quality
(IAQ) impacts and engineering solutions related to the
transport of pollutants from attached garages to
residential living spaces. Natural or fan-induced
pressure differences across air leakage paths in
house-garage (HG) interfaces can result in the transport
of the contaminants generated in garages into adjacent
living spaces. This paper summarizes a literature review
on the transport of pollutants from garages to
residential living spaces and describes a field study to
estimate the range of airtightness of attached garages
and of HG interfaces in the United States. Although the
body of literature on pollutant transport from attached
garages to residential buildings is limited, the studies
reviewed provide substantial evidence that transport of
contaminants from garages has the potential to
negatively impact residential IAQ in either an acute
(e.g., carbon monoxide from automobiles) or chronic
manner (e.g., storage of chemical products). However,
the literature contains more questions than answers on
issues such as the airtightness and geometry of the HG
interface, the impact of heating and cooling equipment
in the garage, and the effectiveness of potential
engineering solutions. In order to address one gap in
understanding these issues, the airtightness of garages
and HG interfaces was measured in five residences using
fan pressurization. While the small sample of houses
limits generalization of the results, a range of house
ages, styles, and sizes was included. For all homes
tested, the garage was found to be at least twice as
leaky as the house, based on air change per hour at 50
Pa. The leakiness of the garage envelope, based on
surface area normalized effective leakage area at 4 Pa
(ELA4/SA), ranges from a high of nearly eleven times to
a low of two and a half timed that of the house exterior
envelope leakage. On average, the HG interface was
almost two and a half times as leaky as the rest of the
house envelope, when based on ELA4/SA. However, this
average is somewhat skewed due to one HG interface
measured in this study that is almost eleven times as
leaky as the rest of the house envelope. Conversely, a
larger Canadian study found HG interfaces to be
comparable to house envelopes but found the average
garage to be about ten times leakier than the houses --
possibly because Canadian houses are consistently
tighter than U.S. houses (Fugler et al. 2002). The
knowledge gained from this review and the field study
will be used in a simulation study of the potential
occupant exposure to pollutants from attached garages
and to explore potential engineering solutions to this
IAQ problem.
