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

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

I used to spend winters in the bathtub because my house was so cold. This was my first winter roaming around my whole house comfortably. This even led me to decorate a little. My heating oil usage has been reduced by over a quarter: I rarely have to boost the thermostat because the temp stays at a constant. The Efficiency Maine rebates, together with the energy savings, make it affordable for me to pay for the loan I took out to finance the project. I do not worry about my pipes freezing.

Claire Helene Bevan

Camden

Awesome company. It was a few years ago that they did the audit and then we commissioned them to do the work. We subsequently sold our house and moved to South Africa, but their level of service and expertise will live on.

Odette Brown

From beginning to end – that is from the moment Justin McEdward stepped into our home to assess our energy conservation needs until the crew left – the Evergreen Home Performance process went absolutely smoothly. Justin made a thorough inspection and took pictures with an infrared camera. His proposal described the scope of work in detail, and he explained what we could expect the proposed work to accomplish. Our proposal was forthcoming within a couple of days, and Justin was available to discuss it and answer questions.

Adrienne Harkavy

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

"Working with Evergreen from start to finish was a great experience." See what our customers have to say about their experience with Evergreen Home Performance. 

Jeff L.

This team of individuals was professional at all times. They set up barriers that kept the dust at a minimum. They conducted an air flow audit and cut the draft circulation from the outside in half by sealing cracks. They hauled out the old insulation and replaced it with blown in insulation with an R - 60 Value. They also did the rebate paperwork so that I could get my $1500.00 rebate from the state of Maine. I highly recommend Evergreen Home Performance!

Daniel B.

Rockland

Thanks Evergreen Home Performance for helping to make our home more efficient. Many thanks as well to Bryan for the initial walk through and recommendations to make our home more efficient and to Dave, Roland, and Jacob for a job that was done professionally and courteous.  We were amazed at the level of efficiency and everyday they made sure to protect our floors, carpets, and furniture. We had daily discussions with Dave about progress and what was being done and where they were at in the project.

Carol Fink

Evergreen came back this year to finish insulating our house. We have been remodeling and renovating an 1850s cape for several years. Their employees are very professional and pleasant to deal with. Over several years Brian Robinson has been able to schedule us in for several small areas that needed addressing and finally turning a room we used to close off in the winter into a comfortable usable space. We primarily heat with wood and since Evergreens great work our furnace has only come on ONCE this winter. Fantastic. Really satisfied customer in Thomaston.

Chris F.

Thomaston

Thorough, smart, informative, integrated, and communicative -- that's how my experience was with Evergreen even with the covid interruption midstream. The team picked up where they left off, insulated basement and air sealed attic and knee wall in 100' temps under the eaves! This business group was a pleasure to work with.

Karen W.

Gray

Several years ago Brian Robinson evaluated the crawl space at my summer home on Islesboro where I knew moisture was becoming a problem. I had done quite a bit of work in the space many years prior with mixed results. When Brian offered some suggestions, they were ideas that incorporated work previously done, and would be a relatively low cost effort to improve the situation. He offered this advice over several phone conversations of some length, informally, and at no charge.

Cliff R.

Islesboro

I cant say enough about this company and the benefits that it created for our family. They are very professional and have effectively re-insulated our home. The heating bill proves the point.

Bob O.

Springvale

I am very pleased with my experience with Evergreen Home Performance. I met several times with Richard Burbank and he was very detailed in his explanations to all of my questions. He provided me with several options for improving the insulation to our home. The team of installers were very professional and respectful of our home. They did a great job of cleaning up every day after the days work and they were also very responsive to all my questions as well as we collaborated to get our home better insulated. It was a pleasure to work with Richard and…

Brian C.

Falmouth

Bryan, Dave and the entire Evergreen team are wonderfully professional, prompt and thorough. I enjoyed working with them and look forward to continued work as we upgrade our home! Thank you so much for your professionalism, fairness, time and diligence.

Cait

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

Portland Buy Local
Efficiency Maine
EPA Lead-Safe Certified
Building Performance Association
BPI Certified