Blower Door Testing

Blower Door Testing

Drafty Rooms. Rising Bills. Freezing Pipes in a Newer Home. What’s Really Going On?

If you’re struggling with comfort issues or high heating costs, the problem might not be what you think. You can’t always see the cracks and gaps letting outdoor air sneak in—or the warm air slip away.

That’s why we use blower door testing: a powerful diagnostic tool that helps us measure your home’s air leakage, pinpoint energy waste, and recommend upgrades that actually solve the problem.

Whether your home is brand new or 100 years old, air leaks could be costing you money and comfort. We’re here to help you find them—and fix them.

Evergreen Team Conducting A Blower Door Test
Setting-up a blower door test in a house

What Is a Blower Door Test?

A blower door test uses a powerful fan installed in an exterior doorway to lower the air pressure inside your home. This forces outside air to rush in through cracks, gaps, and holes—revealing where your home is leaking air.

While the test runs, we use an infrared thermal camera to detect hidden problem areas behind walls, around rim joists, in the attic, and more. Summer’s a great time to conduct this test, as the leaks entering your living spaces from your attic or the outdoors are colored warm or hot, while the colder air leaking up from the basement or crawlspace will show up as cool on our cameras. 

The result? A detailed picture of your home’s energy performance—one that helps us target the right upgrades for maximum comfort and savings.

How Blower Door Testing with Evergreen Works

  1. We prepare your home: closing exterior doors and windows, opening interior doors, covering ashes in wood stoves and fireplaces, and turning off all combustion equipment.
  2. We install the blower door fan in one of your exterior doorways and turn it on, depressurizing your home.
  3. We measure the amount of air coming in to determine how “leaky” your house is.
  4. We then scan with a thermal camera to reveal the exact spots where insulation and air sealing are needed.

This is part of our full energy audit we use to design smart, effective insulation and air sealing upgrades.

Evergreen Blower Door Testing
Blower Door Testing

Why Blower Door Testing Matters for Your Home

A blower door test gives us data, not guesswork. That means smarter upgrades and measurable results.

With the insights from this test, Evergreen can help you:

  • Identify and seal hidden air leaks
  • Improve your home’s comfort and consistency
  • Cut down on heating and cooling bills
  • Reduce strain on your HVAC system, especially recently installed heat pumps and mini-splits
  • Protect indoor air quality by achieving the right balance of airtightness and ventilation

Blower door testing doesn’t just reveal when your home is too leaky—it can also show if it’s too airtight. In homes that have been over-sealed without proper ventilation, indoor air quality can suffer.

We use this information to make sure your home is healthy and recommend ventilation solutions if needed to keep your indoor air fresh, safe, and clean.

Plus, blower door testing is required for Efficiency Maine insulation rebates. We’ll do a pre-project test to establish a baseline and then a final test at the end to confirm the quality of our work and to prepare the final rebate application. 

Trusted Blower Door Testing for Maine Homes

From historic homes to newer builds in Rockland all the way down to Portland, we’ve tested—and improved—thousands of homes across Coastal and Southern Maine.

You don’t have to know whether blower door testing is right for your home—we’ll help you figure that out. Let’s talk about what you’re experiencing and decide on the best next step together.

Exterior view of a Maine Home

Call 207-594-2244 or contact Evergreen online to schedule your free consult.

Uncover the hidden air leaks making your home uncomfortable and expensive to heat.

BOOK YOUR FREE CONSULT

Evergreen has insulated two homes that we've owned now and both times we experienced exceptional service and craftsmanship. Our rep, Justin, went above and beyond answering questions and the installation team was attentive to every detail, including pulling out old poorly installed insulation and redoing a bathroom fan that wasn't up to current code. They also left the place spotless every day! Our home is already so much warmer this fall and we are looking forward to using less oil this winter.

Eva G.

Falmouth

We had Evergreen come out to our tiny old (100+ year old) house to see what they would recommend for decreasing our carbon footprint, saving money, and increasing our comfort in the cold season. Richard and Bryan were great to work with, patiently answering our many questions and walking us through multiple options. We could only afford to tackle a few areas this year; we ended up replacing some windows and having them weatherize the entire house.

Alan M.

Falmouth

Our house still the most efficient home we’ve ever lived in. And we have you folks to thank for that! A special howdy to Brian Robinson please!

Bruce O’Donal and Eva Butler

Evergreen removed and replaced the insulation in my attic. They did a great job!, Crew was excellent, and the whole thing went smoothly, and the attic was NOT easy to get into or work in, so kudos to some hard work done well!

Joel A.

Portland

First we have Evergreen do a BIG project worth about $20K (windows, basement, insulate & rebuild an entire wall, a door, attics, and air sealing). They were so great we had them come back later when we decided we did want to do our other door. They are professional and do great work. They take care of your home and are trustworthy, and on top of all that friendly! I highly recommend you call them!

Garreth C Debiegun

Update 12/2018: Evergreen has completed Phase II of my house (insulating and installing air/moisture barrier on exterior walls, replacing old windows) and now that heating season is upon us, the difference is astonishing. The house is tight as a drum and so easy to keep warm. Worth every penny. Thank you all! Working with Evergreen was a positive experience from start (no charge energy audit) to finish (a MUCH more comfortable home). Brian Robinson spent a lot of time with me on the audit, explaining clearly what he was finding in my ca.

Rebekah W.

Rockport

We just finished a large project air sealing and reinsulating our 1890s basement and attic. It had been completely renovated 8 years ago, but still felt cold, and lacked proper energy assessment and corrections. We met with Justin in December and were very impressed with his knowledge, professionalism and communication skills and knew Evergreen was who we wanted to work with. Dave was our on hands project manager and was excellent. The office staff has been quick to respond and helpful as well when needed.

E Gallant

Kennebunk

We initially contacted Evergreen through Efficiency Maine for an energy audit, which was conducted promptly and professionally by Justin McEdward, one of their Energy Advisors who is BPI-certified. After a thorough inspection of our newly purchased home, Justin explained in great detail what we needed and did not need. It was agreed that Evergreen would remove all of the existing attic insulation, which was not adequate, and replace it with blown in cellulose, to a rating of R-60.

Thomas W.

Scarborough

We are thrilled with the job Evergreen did to transform our 213 year old home into a warm, draft-free, cozy space. The entire team led by Bruce was prompt, courteous, knowledgeable, and hard working. If Evergreen could transform our home in this way, we are sure they would make a comparable difference in YOUR home!

Jonathan M.

Bridgton

From start to finish, our experience was incredible. Justin was extremely helpful. The crew was fast, friendly, and efficient. And most importantly, our home is WAY warmer and our heating is less costly. I'd highly recommend evergreen to anyone looking to upgrade their home!

John S.

South Portland

We had Evergreen energy do blow-in cellulose. I was very happy with the result. They tested with blower-door before and after. House is now MUCH warmer. Also, in the time since when I've had to open walls for various access, I've been impressed with how they got the insulation packed in everywhere. I'd use them again.

Noah

Peaks Island

Great job installing windows and insulation.

Bob S.

Rockland

They were highly recommended. I found them to be very knowledgeable and so helpful, with practical ideas. Despite my not living within their service area, they were generous with their knowledge, describing the usual solutions to correct leaks in my basement, and what the result is likely to be by following path A, B or C, and why. I was discouraged. Talking with Evergreen helped me see that my basement problems are far from insurmountable and really, fairly common in 100-year old homes. There are proven solutions.

Rosalind J

Damariscotta

Our basement was the eyesore of the house. I wanted to make improvements, but first needed to make structural, insulating and moisture mitigation improvements. Evergreen was professional and competent in taking on a complex project of not only encapsulation and insulation of basement and crawlspace, but completed needed improvements to the structural integrity of the wood floor platform above a crawlspace and brought in a concrete contractor to pour where there was once a rotting, tiered wood platform - replacing that area with a more functional and tight tiered concrete area.

Duane B.

East Boothbay

The team members were very professional, worked very hard, paid very close attention to detail and cleaned up meticulously every day. I really appreciated the care they took knowing the smallest details were going to make a big difference to our heating bills. Thank you!

Pam B.

Brunswick

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