What is a Blower Door Test?
What Is Blower Door Testing? Why It Matters for Insulation & Spray Foam in Mid-Michigan
If you’re searching for:
“blower door test near me”
“spray foam insulation contractor in Owosso”
“home energy audit Lansing MI”
“air sealing services Flint”
“why is my house drafty in Michigan?”
You’re in the right place.
Blower door testing is one of the most important tools used in modern building science to measure air leakage in homes and commercial buildings — and it directly impacts how well your insulation performs.
Whether you’re in Owosso, Lansing, Flint, Howell, Saginaw, Midland, Brighton, or Mount Pleasant, understanding blower door testing can help you save money and build smarter.
What Is a Blower Door Test?
A blower door test uses a calibrated fan mounted in an exterior doorway to:
Depressurize or pressurize the home
Measure how much air leaks through cracks and gaps
Quantify air leakage in CFM50 (Cubic Feet per Minute at 50 Pascals)
In simple terms:
It tells you how drafty your building really is.
Why Air Leakage Matters in Michigan
Michigan’s climate (Zone 5/6) means:
Long heating season
Cold winters
Hot, humid summers
Large temperature swings
Air leakage causes:
Heat loss in winter
Humidity problems in summer
Ice dams
High utility bills
Mold and condensation issues
Poor comfort
Insulation alone does not stop air movement.
That’s where blower door testing and proper air sealing come in.
How Blower Door Testing Connects to Spray Foam Insulation
Spray foam insulation is one of the only insulation materials that:
Insulates
Air seals
Reduces moisture movement
Fiberglass and cellulose slow heat transfer, but they do not stop air leakage.
When we perform a blower door test before and after installing spray foam in areas like:
Rim joists
Attics
Crawl spaces
Basements
Pole barns
Commercial buildings
We can measure real, quantifiable improvement.
This is why people searching for:
“best insulation for Michigan homes”
“spray foam vs fiberglass”
“energy efficient insulation Lansing”
“closed cell spray foam cost Flint”
Often end up learning about blower door testing.
Because air leakage is the hidden energy thief.
What Happens During a Blower Door Test?
During the test:
A powerful fan is installed in an exterior door.
The home is depressurized.
Air is pulled through all leaks.
We use smoke pencils or infrared cameras to identify leakage areas.
We measure total air changes per hour (ACH50).
This gives a clear picture of:
How tight the home is
Where the biggest leaks are
What insulation or air sealing improvements will make the biggest difference
What Is a “Good” Blower Door Number?
Typical results in Mid-Michigan:
Older homes (pre-1990): 7–12 ACH50
Average home: 5–7 ACH50
Energy-efficient home: 3–5 ACH50
High-performance home: <3 ACH50
Modern building codes increasingly require lower ACH50 numbers.
If you’re building in areas like Lansing, Brighton, Howell, or Grand Blanc, blower door testing is often required for inspection approval.
Where Air Leakage Commonly Happens
In homes across Owosso, Corunna, Perry, Durand, Flint, and Saginaw, we commonly find leaks at:
Rim joists
Attic top plates
Recessed lighting
HVAC penetrations
Basement sill plates
Attached garages
Pole barn roof seams
Spray foam insulation is especially effective in these areas because it expands and seals gaps.
Blower Door Testing & Energy Savings
Reducing uncontrolled air leakage can:
Lower heating costs
Reduce cooling costs
Improve comfort
Prevent condensation
Extend HVAC life
Improve indoor air quality
For homeowners in Midland, Bay City, Mount Pleasant, Lansing, and Howell, energy savings often offset insulation upgrades over time.
Why Spray Foam Performs So Well Under Blower Door Testing
Closed-cell spray foam:
Creates an air barrier
Adds structural strength
Provides vapor control
Improves R-value per inch
Open-cell spray foam:
Excellent air sealing
Great for attics and wall cavities
When paired with blower door verification, you’re not guessing — you’re measuring.
Who Needs a Blower Door Test?
You should consider blower door testing if:
Your home feels drafty
You’re finishing a basement
You’re building new construction
You’re upgrading insulation
You want lower energy bills
You’re installing spray foam
You’re preparing for code inspection
It’s especially common in new builds around Lansing, East Lansing, Brighton, Howell, and Grand Blanc.
Building Science in Simple Terms
Building science looks at how:
Heat
Air
Moisture
Materials
Interact in a structure.
Blower door testing measures air movement.
Spray foam controls air movement.
That’s why the two are closely connected.
Final Thoughts for Mid-Michigan Property Owners
If you’re in:
Owosso
Lansing
East Lansing
Flint
Grand Blanc
Fenton
Howell
Brighton
Saginaw
Midland
Bay City
Mount Pleasant
Corunna
Durand
Perry
Understanding blower door testing can help you make smarter insulation decisions.
Spray foam insulation paired with proper air sealing verification is one of the most effective ways to improve energy efficiency in Michigan’s demanding climate.