A blower door test is a big fan in a door frame that pressurizes the house and measures how leaky it is. It sounds like a nice-to-have. On some Ontario permits it is required, and on many more it saves real money.
Here is when SB-12 needs one, the targets, the right time to test, and how a good number can shrink your heat loss and your equipment.
Some compliance packages let you use proven airtightness as one of the items. If you use it, the house has to be tested and hit the target.
If your energy model assumes the house is tighter than the default, a test has to back it up.
Many energy programs require a test. Check the rules of any program you are building to.
For the SB-12 airtightness option, the targets shown on Kitchener’s energy form guide are 2.5 air changes per hour at 50 Pa for detached houses and 3.0 for attached. Confirm with your building department’s current form.
Before drywall. Air barrier done, windows in, penetrations sealed. Leaks are easy to find and easy to fix.
At the end, for the record. This is the number that counts for credits and modelling.
If the final number misses the target, you want to know what to fix before the inspection, not after.
The test report goes with your permit file and any program paperwork.
Tests are done to CGSB 149.10 or ASTM E779 by a qualified tester.
A measured air leakage number can replace the default in the CSA F280 heat loss. Tight houses often get a smaller load.
A smaller load can mean a smaller furnace or heat pump. That is real money.
On the airtightness option, a good test can help you meet SB-12. See SB-12 explained.
Fewer drafts, less dust, fewer cold spots. You also need good ventilation once it is tight. See HRV design.
We build ICF homes, and they tend to test tight because the walls are one continuous piece. The leaks are usually at the roof, the windows and the penetrations, not the walls. A mid-construction test finds them while they are still easy to seal.
If you have a test result, send it with your drawings. We use it in the heat loss.
Have a blower door number? Send it with your drawings. We use your real air leakage instead of the default.
Get Free Quote →Not always. You need one if you use the SB-12 airtightness option in a compliance package, or if your energy model assumes the house is tighter than the default. Otherwise it is optional, but it is still a good idea.
For the airtightness option, the targets shown on Kitchener’s energy form guide are 2.5 air changes per hour at 50 Pa for detached houses and 3.0 for attached. Check the current form your building department uses.
Do a mid-construction test before drywall, when you can still find and fix leaks. Then the final test for the record. Testing only at the end means finding leaks you can no longer reach.
It can. A measured air leakage number can replace the default assumption in the CSA F280 calculation. A tight house tested as tight often gets a smaller heat loss and smaller equipment.
Blower door tests in Canada are done to CGSB 149.10 or ASTM E779. Use a qualified tester and keep the report.
It varies with the house and the region. Compare it with what it can save: a credit on the energy package, a smaller heat loss, and leaks found while they are still easy to fix.
Send your drawings and your blower door report if you have one. We calculate the heat loss with your measured air leakage.