Blower Door Testing
The gold standard for measuring how airtight your home is — and the first step toward real energy savings.
What Is a Blower Door Test?
A blower door test is a diagnostic procedure that measures how much air leaks in and out of your home's building envelope — the walls, ceiling, floors, windows, and doors that separate your conditioned living space from the outside.
We mount a calibrated fan in one of your exterior doorways, seal it in place, and use it to depressurize the house to a standard pressure of 50 Pascals. By measuring how hard the fan has to work to maintain that pressure, we calculate your home's air leakage rate — expressed as ACH50 (air changes per hour at 50 Pascals).
The result tells you — and your contractor — exactly how leaky your building envelope is, where the biggest problems are, and what improvements will have the greatest impact on comfort and energy bills.
What Happens on Test Day
Preparation
We arrive with our calibrated Minneapolis Blower Door system. You'll need to close all windows and exterior doors, and turn off combustion appliances like furnaces and water heaters. The whole setup takes about 15 minutes.
Pressurization & Depressurization
We run the fan in both directions — pressurizing and depressurizing the home — to get an accurate, repeatable measurement. The test itself takes 20–30 minutes.
Leak Detection (Optional)
While the house is depressurized, we can use a smoke pencil or thermal camera to pinpoint exactly where air is entering — around outlets, at rim joists, through attic bypasses, and more.
Results & Report
You receive a detailed written report with your ACH50 score, a comparison to code requirements and energy-efficient benchmarks, and recommendations for air sealing improvements.
Understanding Your Results
What does your ACH50 score actually mean?
Common in homes built before 1980 with no air sealing. Significant energy loss and comfort issues.
Typical for homes built in the 1980s–2000s. Improvement is cost-effective and impactful.
Required for new construction in most Midwest states. A reasonable target for existing home retrofits.
Achieved with careful air sealing during construction or a deep energy retrofit.
Why Get Tested?
For Homeowners
- Find the hidden air leaks driving up your heating and cooling bills
- Diagnose drafty rooms, cold floors, and uneven temperatures
- Get a certified report to qualify for utility rebates and tax credits
- Prioritize air sealing work for the best return on investment
- Verify that air sealing work was done correctly after the fact
For Contractors & Builders
- Meet IECC 2021 blower door testing requirements for new construction
- Get a certified third-party test report accepted by building departments
- Fast scheduling to keep your project on track
- Detailed documentation for permit closeout and homeowner records
Ready to test your home?
Get a free quote for blower door testing. We serve homeowners and contractors across the Midwest.