What Does A Blower Door Test Do?

You might need a blower door test for your home. But what’s the goal of blower door testing? What does one of these tests do?

South Central Services offers certified blower door testing. We service areas like Harpers Ferry, WV, and Hagerstown, MD.

By the end of this article, you will understand:

• What blower door tests are used to quantify
• What blower door test results mean
• How blower door tests can help you
• What happens during a blower door test

Don't have time to read right now? Check out everything you need to know at a glance.

Blower Door Tests Quantify Air Leakage In A Building.

Blower door testing is a precise method of calculating air leakage. These tests quantify results as the number of air changes per hour (ACH). Essentially, how much air is exchanged between the inside and outside of the building within an hour?

If air is not exchanging mechanically (through your HVAC system) or naturally (through a door or window), then there is an air leak. Blower door tests can tell you how leaky a building is.

Blower Door Tests Determine If Buildings Are Energy Efficient.

The reason why blower door testing exists is because air leaks waste energy.

Traditionally, leaks were considered a good part of construction, because they let the house "breathe" a little. In more recent years, the role of air leakage in energy waste has been discovered.

Since energy is an expensive and precious resource, it makes sense not to needlessly waste it. The International Energy Conservation Code (IECC) has made blower door testing a requirement for new construction buildings. This requirement will help ensure that new buildings do not allow air to leak excessively between the inside and outside of the building.

Blower Door Tests Show Where Air Leakage Is Happening.

Air leakage happens within the thermal envelope of a building. The thermal envelope usually includes:

• Attic
• Basement
• Crawl space
• Exterior walls

Any gaps or cracks in these areas, which form the barrier between the building and the outside world, can result in air leakage.

If a building is leaky, you can assume there are air leaks in some of these four areas. However, a blower door test allows you to be more specific about what area of a home is compromised.

By not assuming the problem, you can directly address and resolve air leakage. Once air leakage is fixed, energy costs lower significantly.

Blower Door Tests Pressurize Or Depressurize A Building.

So, how exactly does a blower door test work?

A certified technician installs a blower door fan in the exterior door of a building. When the fan is turned on, it either blows air inside or pulls air outside. The blower door test will work whether the building is pressurized or depressurized.

The technician then uses specialized equipment to carefully measure any air that exchanges. You can visualize this like an open window. If a fan pulls out all of the air in the room, an open window will let new air back inside. The blower door test finds any cracks or gaps that let air exchange.

When the test is complete, the technician can provide an official report quantifying the ACH.

The Bottom Line About What Blower Door Testing Is

Blower door testing has become a requirement for new construction homes via the IECC. A certified technician must perform a blower door test. These tests quantify air exchanges in the building. Blower door testing aims to identify and resolve any problematic air leaks that will cause excessive energy waste over the structure's lifetime.

Now that you understand what a blower door test is, your next step is to:

• Discover how much blower door tests cost
• Request a blower door test from South Central Services