While most modern homes are designed to be airtight, over time, cracks will likely develop. But how does a homeowner determine just how airtight his or her home is? A blower door test can provide the answer.
A blower door test might help you:
- Identify where cold air is leaking in
- Keep conditioned air from leaking out, reducing energy consumption
- Prevent moisture condensation
- Determine how much mechanical ventilation is needed
How Does It Work?
A technician will mount a calibrated fan fitted to a flexible panel inside the frame of an exterior door. Once the powerful fan is turned on, the air pressure inside your house will lower as all the air rushes out. Higher pressure air from outside will then rush in through all the cracks and crevices in your home.
A manometer measures in cubic feet per minute (cfm) how much airflow is needed to achieve a specific target calibration, expressed in units of pressure called Pascal, and for blower door tests, the measurement is 50 Pascal. More airflow is needed to maintain this target in a leaky house, so this tells the technician how airtight your house is or isn’t.
Blower door results are also measured by air changes per hour (ACH). This is determined by how much air needs to be pumped at 50 Pascal during an hour to completely replace your home’s air. A new home with only average air sealing usually measures seven to 10 air changes per hour at a rate of 50 Pascal, so that’s 7-10 ACH50.
A smoke pencil helps the technician locate places where conditioned air is getting out or where unconditioned air can get in. Infrared analysis also helps locate leaks. Generally, another blower door test is administered after improvements to see if they are effective.
Contact Hansberger Refrigeration and Electric Company for more information about the blower door test, as well as other issues pertaining to your Yuma home’s comfort.
Our goal is to help educate our customers in Yuma, Arizona about energy and home comfort issues (specific to HVAC systems). For more information about blower door tests and other HVAC topics, download our free Home Comfort Resource guide.
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