HOW IT WORKS
LEAP’s professional energy auditors use blower door tests to help determine a home’s airtightness, i.e. identify air leaks. This is one of the most critical steps in learning how efficient your home is.
A blower door is a powerful fan that mounts into the frame of an exterior door. The fan pulls air out of the house, lowering the air pressure inside. The higher outside air pressure then flows in through all unsealed cracks and openings. This test determines air leakage and unintentional introduction of outside air into a building. Air leakage should be minimized to reduce dust, increase thermal comfort and reduce energy consumption. A blower door test can help establish the proper building tightness.
BENEFITS OF A BLOWER DOOR TEST
Exposes air leaks that are a major contributor to wasted energy (and, therefore, wasted money)
Exposes air leaks that may cause moisture condensation problems and mold
Exposes air leaks may cause uncomfortable drafts of cold air leaking in from the outdoors
Exposes ventilation issues that may contribute to indoor air quality problems
TECHNICAL BREAK-DOWN OF THE BLOWER DOOR
Blower doors consist of a frame and flexible panel that fit in a doorway, a variable-speed fan, a pressure gauge to measure the pressure differences inside and outside the home, and an airflow manometer and hoses for measuring airflow.
There are two types of blower doors: calibrated and uncalibrated. LEAP auditors use a calibrated door. This type of blower door has several gauges that measure the amount of air pulled out of the house by the fan. Uncalibrated blower doors can only locate leaks in homes. They provide no method for determining the overall tightness of a building. The calibrated blower door’s data allow the auditor to quantify the amount of air leakage and the effectiveness of any air-sealing job.
PREPARING FOR A BLOWER DOOR TEST
Before an auditor arrives, you can prepare your home for a blower door test:
Close windows and open interior doors
Turn down the thermostats on heaters and water heaters
Cover ashes in wood stoves and fireplaces with damp newspapers
Shut fireplace dampers, fireplace doors, and wood stove air intakes.