Blower Door Testing … what is it and why is it important?!

Blower door testing is back!  Now that the lockdown in Toronto has been lifted, we are proceeding this week with ‘pre-construction’ blower door tests for 4 of our current projects.

Blower door testing is used to measure the air tightness of a home.  Identifying and addressing leaks is a key factor in improving a home’s energy efficiency, comfort and durability.

During a blower door test, all windows and doors are closed and a fan is placed in the frame of the main door.  The fan is run to depressurize the house, drawing air through all the small holes.  The operator determines the ACH (air changes per hour) based on the readings, dimensions and volume of the home.

Locations of leaks can be determined using a ‘smoke pencil’ (though the back of your hand can do just as well)

This project, an older semi in Leslieville that underwent a major renovation and addition, was tested last year.  In this case the tesing company also used a technique where the fan was reversed, the house was filled with theatrical fog then pressurized to see where the smoke would exit the house.  Good thing we had notified the neighbours as a large hole was found on the party wall!  Compartmentalizing attached homes (sealing them off from each other) can also help with sound and odour transfer.

Unfortunately we do not have a ‘before’ reading for this project, but, judging by what was found during the reno, we expect the reading would have been 15 ACH or higher.  The first construction test got a reading of approximately 8 ACH and in the end, the house was brought down to 3.4 ACH.  This is below the level required for new home construction (for attached homes).  As we move homes toward Net Zero, we aim to achieve 1.0 ACH or less.

Questions?  Looking to improve the energy efficiency and comfort of your home?  Get in touch!  As you can see, we love this stuff!