How a Blower Door Test Can Help Improve Your Home Comfort and Indoor Air Quality

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Has your older Maine home been a bit drafty lately, or have you noticed an increase in dust throughout your home? Or maybe you’ve realized that your new home is costing you more than you estimated for utility costs, and your heating and cooling equipment are struggling to keep you comfortable. These are all signs that your Maine home is full of air leaks. 

Regardless of what is causing you to take notice of the air leaks in your home, you probably want to resolve the issue, and residential air leakage testing can be a great help. Blower door tests are the industry standard when it comes to whole-house air leakage tests, and they’re used to resolve home air leakage rates that are too high for optimum comfort and efficiency. Here is what you need to know about how they work and how you can benefit.

What Is a Blower Door Test and How Does it Work?

The blower door test was invented in Sweden in the ’70s and had shown up in American homes by 1979. The goal of a blower door test is to provide a reading of the total air leakage throughout a building, and this is done by attaching a large fan to an exterior door with a special pressure gauge device attached. 

A blower door is temporarily attached to a home using an airtight skirt made of a plastic material, then all other exterior doors and windows must be shut, while interior doors remain open. Once the set-up is complete, your blower door technician will turn the fan on to create a negative pressure inside the home (the fan blows the air out, not in). 

After a few adjustments to complete the pressure gauge readings, the blower door test is complete and your blower door technician will be able to assist you in understanding the findings!

Understanding Blower Door Test Measurements

When a blower door fan creates a negative pressure within your home, outside air is pulled into your living space through whatever pathways it can find. With all of your outside windows and doors shut, this only leaves tiny, hard-to-reach, and often invisible air leaks for outside air to travel through. At this point, the pressure gauge is measuring:

  • If your home is airtight enough to reach 50 pascals

  • How many times the air in your home is replaced with outside air (Air Changes per Hour, or ACH)

  • The resulting air leakage in Cubic Feet per Minute (CFM)

  • How much air infiltrates your home naturally, without the blower door

These measurements are used to understand how air moves freely into and out of your home. So, how can an experienced home performance contractor like Evergreen Home Performance use the results of your blower door test?

What Happens Next?

A blower door test is all a part of a greater home diagnostic service, called an energy audit, and the data is used to select the measures needed to increase the overall comfort and efficiency of your living space. Your Evergreen Home Performance Energy Advisor can utilize infrared thermal imaging during the test to help locate the air leakage locations. Then, when your Evergreen technician crew arrives to air seal, they seal them up until your home is as airtight as possible. This is called air sealing

Air sealing provides you with greater control over your indoor temperatures, and the blower door test data helps determine how much ventilation your home needs to keep it safe and healthy. Usually, existing home ventilation equipment (like range hoods and bathroom fans) can be optimized to do the job.

What’s more, the same infrared imaging can be used to locate areas of poor insulation. Replacing outdated or damaged insulation can increase the overall effectiveness of your home improvement project, and should be completed alongside air sealing. 

With proper air sealing  and insulation, your Maine home will be:

  • More comfortable

  • Healthier to live in

  • Less expensive to heat and cool 

  • Less drafty

Want to keep Maine’s unpredictable outside air away from your comfortable and healthy home? Schedule an energy consult with Evergreen at or get in touch here.

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I had gotten estimates from several other companies, but Evergreen was in another league entirely with their professionalism. If you want the job done correctly, I couldn't recommend this company enough.

Rayna Mayo

Freeport

My experience with Evergreen was excellent. From their thorough and thoughtful initial consultation to their detailed post-work visit, the team was professional, knowledgeable, and responsive. Their workmanship was top notch. Our home is now much warmer and more efficient. I highly recommend their services!

Douglas R.

Edgecomb

We had Evergreen redo the insulation in our roof. The team handling our project did a great job. They left the house spotless. We've already noticed the difference in how much better our house is retaining heat. I would definitely recommend and will use them for future projects.

Ffej C.

South Portland

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

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

Evergreen did a fantastic job replacing 28 windows in our house. They were friendly, courteous, and very detail oriented. Brian did a great job planning, estimating and executing the project. Our energy use has dropped significantly since the work was done.

Alex B.

Kittery

We had a fantastic experience working with Evergreen to insulate our roof this winter. Everyone was extremely friendly throughout the process - the crew at our home worked hard, were approachable with questions, and the team leader even showed me around the project to point out specific areas they were working to improve.

Joel Wentz

Evergreen did everything they said they would and more. I actually don't mind going into the basement now since they sealed it. The air quality in the house is noticeably better and it's warmer in the winter. We can even store clothing down there where before, whatever was in there would mildew. Even the spider population declined! I used to vacuum so many of them from the corners of the ceilings in the house. Not any more!

Loriel Van Dusen

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

I never leave reviews, but had a great experience with Evergreen and wanted to spread the word! In short, we worked with them to insulate our roof this winter and have noticed surprising immediate results. The constant ice dams I have wrestled with are completely gone, and the home is noticeably more comfortable. It's a little too early to tell if our oil bill is going to reduce, but I imagine we will see an impact there as well.

Joel W.

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

I was extremely pleased with the professionalism and quality of service that I received from the Evergreen team. I met Richard to discuss options for insulation. I knew immediately that I wanted to do business with them because he did not try to over-sell extra services that I did not need. Dave was the project manager. He was not only kind, but very respectful of my home. I would highly recommend this company.

Darlyann M

Bath

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

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

Evergreen completed the work at my home thoroughly and professionally. An inspector from Efficiency Maine came to inspect afterwards and described it as "state of the art" and "outstanding". The crew was very pleasant and considerate during the project. Their cleanup each day was perfect. Communications with the office were easy and reliable. I am very satisfied.

Catherine H.

South Portland

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