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4. Calculate Building Tightness Levels (Minimum Ventilation Requirements)
If the home has had a blower door test done (which we all will do as energy auditors), use the formula below.
0.052 x CFM50 x S x wsf = "infiltration credit" (Qinf)
S = # of stories
wsf = shielded weather factor from table below for each city
0.052 = from the density of air and other factors
Qinf = infiltration in CFM required
ASHRAE Standard 62.2-2010
The minimum ventilation requirement is also called:
They are all the same standard for ensuring adequate air quality for the homeowners. Because our work involves air sealing, duct sealing and tightening a home up, there is a real possibility that the home becomes too tight and unsafe for the homeowners.
BPI is currently using ASHRAE 62.2-2010 to calculate the minimum ventilation requirement, however in the past they have used previous versions of the ASHRAE standard 62.2. There are easy to use Android and iPhone apps to easily help you calculate the ventilation standard. When doing your field exam, it's important to know that you may will be asked to measure the CFM of the bathroom exhaust fans.
BPI Press Release http://www.bpi.org/news_pm_june_2012.aspx
3a. Applied diagnostics and troubleshooting