We are often asked why homes need blower door tests. For Florida home builders, blower door testing is important now that it is required by the Florida building code and necessary to obtain a certificate of occupancy (“CO”). The requirement applies to new residential homes and multifamily buildings three stories or less. RunBrook can help, with experienced, certified professionals equipped to handle multifamily and production home blower door testing.
In addition to being required by code, a blower door test is important for other reasons, which you can learn about below.
First, what is a home’s envelope?
In the building industry, a home'‘s '“envelope” is the physical separation between conditioned and unconditioned areas of the home. The envelope provides shelter and resistance from air, water, heat, light and noise. With regards to air, a home has inward leaking air and outgoing air. through its envelope. The image below is an example of a home’s inward leaking air and outgoing air.
A blower door test makes sure that a home’s envelope is just right - not too loose and not too tight
The purpose of the blower door test is to make sure that a home’s envelope is just right - not too loose and not too tight.
If the envelope is too loose, then too much unconditioned air is coming into a home. By code, this would be a home testing at more than 7 air changes per hour. In that case, additional sealing will be required. If additional sealing is not added, the home could end up with mold problems and a large air conditioning bill.
If the envelope is too tight, then not enough air is coming into a home. By code, this would be a home testing at less than 3 air changes per hour. In that case, mechanical ventilation may be required. Otherwise, the home will have stale, unhealthy indoor air that is not adequately replaced with outside air.
So, why do homes need blower door testing?
Testing is required by the Florida building code and necessary to obtain a CO.
Testing helps builders catch and fix envelope issues that could result in mold issues or unhealthy air.
Testing helps builders check the quality of subcontractors’ work, such as window installations, insulation, and other trades.
Testing can help homeowners feel better about their indoor air quality and electricity bills.