A blower door test is a diagnostic procedure used to measure the airtightness of buildings.
It can identify air leakage and help improve energy efficiency.
During the test, a blower door fan is mounted into an external doorway, and either pressurises or depressurises the building to reveal unsealed cracks and openings through which air can enter or escape (infiltrate or exfiltrate).
This process is crucial for determining how much air leaks in or out a home, which can impact heating and cooling costs, comfort levels, and indoor air quality.
Professionals use this test to recommend improvements and ensure that heating and cooling systems are properly sized. The results of a blower door test can guide homeowners in making targeted upgrades to enhance their home’s energy performance and comfort.
Here’s how it works:
- The blower door fan depressurizes the house by pulling air out, which lowers the indoor air pressure.
- The higher outdoor air pressure then flows in through all unsealed cracks and openings.
- A pressure gauge, called a manometer, measures the pressure differences inside and outside the home.
- The rate at which air infiltrates the home is recorded, often in terms of Air Changes per Hour (ACH).
- The test can also be conducted in reverse, with the fan blowing air into the house to create positive pressure. During the test, professionals may use an infrared camera or a smoke pencil to detect the specific locations of air leaks.
Blower door tests are important for several reasons:
- They help reduce energy consumption due to excess air leakage.
- They prevent moisture condensation problems and uncomfortable drafts.
- They control the entry of outdoor contaminants, pests, and odours.
- They assist in determining the proper sizing of heating and cooling equipment.
- They indicate whether mechanical ventilation is needed to maintain indoor air quality.
