Calculating Infiltration: Implications for a Construction Quality Standard

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Extensive work in inf1ltratio~ measurement and modeling has
led to a simple method to calculate the leakage area of a
house regardless of design or weather conditions. The leakage
area, in turn, is used in the LBL infiltration model to
calculate infiltration for any ~eather condition. This
method, which uses fan pressurization to measure the leakage
area, has been used in a survey of over 300 houses located
throughout North America. This paper presents the results
of that survey and suggests that the present capability in
infiltration modeling offers an excellent framework for an
air leakage standard ·for residential building. Examples of
the interpretation of such a standard are described based on
the ventilation rates adopted in ASHRAE Standard 62-1981.
The results of the interpretations illustrate differences in
structural requirements that will occur when such a standard
is applied to several ventilation system designs.

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Lawrence Berkeley Laboratory