Blower Door Tests (AKA - Air Leakage Test)
A blower door test is the process of testing how air tight your house or structure is. It’s also known as an air leakage test and is usually completed after your project is complete but before you move in. (It’s much easier to fix any needed issues to pass the test before furniture and belongings are moved in.)
Your local building department should have told you what the requirement is to pass the inspection during the permit process. For many years, it has been five air changes per hour (ACH) in my state. They have just recently provided an option for three ACH to gain more energy credit points. Five ACH is reasonably easy to pass, while three ACH takes a little extra effort - usually during the rough-in phase of construction - to pass. Contractors normally will have to spend some extra time sealing penetrations in stud cavities to pass three ACH, but it's do-able.
The actual test is completed by someone who is certified within your state to perform the test. Though it sounds very official, it’s really pretty simple. Essentially what the tester will do is place a big fan in one of your exterior door openings and suck air outside. I highly recommend that you are there for the test, and have a tube of caulk and a can or two of foam insulation spray. If while the test is in progress it looks as though your house is not passing, you can walk around the house to fill gaps, cracks and holes where a lot of air is penetrating into the house. A lot of times it will be outlets, light fixtures, around plumbing pipe penetrations and crawl/attic accesses.
Once the test is done and completed, the testing agency should leave a copy of the test for you and one for the inspector. In our state, they like to see a copy of the inspection result taped up near the electrical panel. Your state might have different requirements.
If you are having difficulties finding someone to do a blower door test for you, my recommendation would be to contact your HVAC and insulation contractors that you may have used on your project. Some of these contractors are certified to do the tests and if not, one of them should have some suggestions on who to call.
Happy testing (and caulking!)
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