The Blower Door Test is a powerful tool used to assess the energy efficiency of a home, particularly to identify air leaks and insulation gaps that may not be visible during a visual inspection. This test is an integral part of energy audits. Furthermore, all new construction homes in Maine are required to have a blower door test completed before occupancy.

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How It Works:

1. Preparation: The Energy Advisor prepares your home for the test by ensuring all exterior doors and windows are closed, interior doors are open, and any combustion equipment (like stoves or fireplaces) is turned off.

2. Setting Up the Blower Door: The blower door, a large and powerful fan, is fitted into one of your exterior doorways in a frame. This fan pulls air out of the house, creating negative pressure inside. Depending on the situation we can also use it to pressurize the home.

3. Airflow Assessment: The negative pressure forces outside air to rush into the house through cracks, gaps, and holes in the building's exterior (also known as the "building envelope"). The blower door gauge measures how much air is leaking into the home, providing a clear picture of the level of air infiltration.

4. Infrared Camera Inspection: After the air pressure inside the home is sufficiently lowered, an infrared thermal camera is used to detect hidden leaks and insulation problems. The thermal camera can pinpoint where air is entering or escaping, even in hard-to-reach or hidden areas like behind walls. Many places in the home will easily be found with your hand.

 

Why It's Important:

• Identifies Energy Loss: Many homes, both old and new, experience significant energy loss due to air leaks. This can increase heating costs, as valuable heated air escapes during winter. In addition, without proper sealing, homes may lose conditioned air throughout the year, contributing to higher energy bills.

• Improves Comfort and Health: Sealing air leaks not only boosts energy efficiency but also improves the indoor environment by preventing drafts and creating more consistent temperatures. Moreover, too little air leakage can lead to poor indoor air quality (IAQ), trapping contaminants indoors. A properly balanced air flow promotes healthier air quality.

• Long-Term Benefits: The results from the blower door test guide energy auditors in designing effective upgrades to your home’s insulation and air sealing. With the right interventions, you can enjoy:

  • A more airtight home

  • Lower heating and cooling costs

  • Enhanced comfort

  • Better indoor air quality

 

Overall, a blower door test is a valuable diagnostic tool that can significantly improve your home's energy efficiency, comfort, and health, making it a smart investment for homeowners in Maine looking to optimize their home's performance.