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

Really great experience from start to finish with Evergreen. They helped us prioritize what needed to be completed first, and has made a significant difference in our hearing costs already. Plus they were really friendly and considerate to work with!

Amy W.

Kennebunk

Professional, friendly and hard-working staff. The product/approach they use for insulation is top notch. We felt the difference immediately, both from added warmth and eliminating drafts. The team and management were easily available to answer our questions or coordinate meeting times. Highly recommended.

Kevin J.

Yarmouth

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

The Evergreen crew who installed insulation in my attic were fantastic! They were very professional, worked exceedingly hard, and they did an excellent job. They were very pleasant and friendly to be around. They cleaned up beautifully after each work day, and left my home in great shape on when they walked out the door for the last time. I can't believe they were able to accomplish all that they did with heat soaring into the 80s and 90s. It was pretty unbearable up there! They have my highest praise and my gratitude.

Cynthia F.

South Portland

We had Evergreen Home Performance of Rockland come in to make our home more energy efficient, and what a TOP notch crew. Brian and his crew did an amazing job from start to finish. Very knowledgeable and professional. We would Definitely highly recommend this crew to anyone who is looking for energy efficiency in their home with a company that truly is an expert and knows how to do a quality job and truly cares about their customer.

Melissa S.

Owls Head

Very easy process, start to finish.  Friendly, professional, and really know their stuff.  They made some improvements to our condo and we were very happy with how it played out.  Would definitely recommend them.

Clayton Eames

Nothing but good things to say. The guys that came and did the actual work were extremely nice and did a great job. The energy audit was thorough and I was presented with multiple improvement options, I was even given ideas for improvement that Evergreen didn't offer. I never felt like I was being "sold".

Ryan Adams

The Evergreen Team did a fabulous job, well exceeding our expectations, In just over a week they transformed our very drafty, noisy 213 year old house into a snug, draft-free, quiet haven with warm floors! The team was prompt, did everything they said they'd do and more. We are thrilled!

Trudy M.

Bridgton

We are so pleased with the work the team from Evergreen Home Performance did in our home. The project included encapsulation of our basement with a reinforced vapor barrier, installation of a sump pump, spray foam insulation on the walls and insulation of the heating duct work. Everyone at Evergreen was friendly and professional. The project was completed on time and in budget. Our home is much cozier and warmer since the project was completed.

Linda Metzger

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

Last week, my oil company asked if we were using some other kind of fuel because our usage was so much less than they had expected We are very happy with the results; the house is much more comfortable

Steve T.

St. George

Evergreen listened and produced a thoughtful evaluation, proposal and comprehensive plan for our attic and basement. They exhibited excellent workmanship, teamwork, and came back as planned after the completion of the job to test the outcomes. Their overall performance as insulation and home improvement contractors is truly outstanding and we highly recommend them.

Susan S.

Saco

The Evergreen team was amazing from initial assessment and planning to the crew that came to complete the work. Our basement encapsulation is the best money we've spent on our house by far. The work was thorough and high quality. And what a wonderful group of people to work with. I highly recommend Evergreen!

Martha Bracy

Evergreen did a fantastic job insulating our 1930's home. The onsite team was professional, clean, and really just a joy to interact with throughout the process. A blower test at the end showed a significant decrease in air leakage. I highly recommend Evergreen.

Kristen H.

South Portland

Evergreen is the "go-to" company for improving the efficiency of your home. There are others to choose from but none so effective, honest, and capable as Evergreen. They did a great quantity of dense packing cellulose to improve our home (both for energy efficiency and for sound insulation) and it was totally successful. They are on-time, helpful, and caring. They clean up to a level that can't be over emphasized. This was the second time we employed them and we'd use them again if the opportunity came. You'll not be sorry to select Evergreen.

Dirk F.

Belfast

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Efficiency Maine
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Building Performance Association
BPI Certified