Greenlight Blower Door Testing

A blower door is a significant diagnostic tool for measuring air infiltration rates and locating air flow pathways through and within a buildings thermal envelope

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Why Blower Door Testing!

Did you know the Washington State Energy Code Requirements now require blower door testing for air leakage on new construction and many types of remodeling projects.

A blower door test measures how airtight your home is. Your home’s air tightness plays a major role in the overall energy efficiency of your home! During a blower door test, your Registered Energy Advisor will run a fan that sits in the main exterior door frame of your home. The fan draws air from the inside of your home to the outside. The air then rushes back into the home through any cracks, gaps, or leaks. As the fan is running, your energy advisor will collect data from the pressure gauge that is used to calculate the airtightness of your home.

After the blower door test has been conducted, your Registered Energy Advisor will provide you with an EnerGuide label, that indicates your home’s rating of energy efficiency. Along with the label, you’ll receive a list of recommended upgrades for your home. The list of recommended upgrades will outline how much your home could improve, should you wish to complete those renovations!

Meet Your Tester

Tamra Marlowe is a certified Blower Door Tester, serving Thurston, Gray Harbor County and surrounding areas. She thrives on finding solutions and providing guidance. She learns every day; both with her formal education and through the nuances of life. She has a positive outlook and strives to bring joy and light to the world around her. If you need answers to quantify the amount of air leakage through your enclosure, contact Tamra and let her help you.

What To Expect

The blower door seeks to answer the two questions of how much air is leaking in and out of a home, and exactly where that air is leaking out. Normally, this information is very hard or nearly impossible to find, as even fairly large leaks are difficult to identify with the naked eye. The blower door at its core is simply a large, finely calibrated fan paired with a manometer– a sensitive device that measures air pressure. A door is set up to create a tight seal over the front door of a home, and the manometer is set up to read the air pressure both inside and outside the home. All exterior doors and windows are shut, and all interior doors are opened for the test.

The fan is turned on and slowly dialed up in speed, blowing air out of the home. This causes the home to drop in pressure relative to the outside. The temporarily depressurized home sucks in air from outside through whatever cracks and leaks it has in its exterior at a rapid rate. These are the areas to be targeted for air sealing– the major problem areas of the home’s shell. During a blower door test, an auditor is able to walk around a home to identify what rooms, windows, attic spaces, or other parts of the home are the leakiest. Paired with an infrared camera, even the tiniest of cracks or temperature differences are brought out with a blower door.

In addition to these qualitative observations, the blower door gives us a quantitative measurement about the leakiness of a home. When a home levels out at a predetermined depressurization (normally 50 Pascals below the pressure of outside), the rate of air leaking into the home is equal to the rate of air being blown out of the home through the blower door fan. This rate of air, measured in cubic feet per minute, can be converted to determine the air change rate of the home.