Everything You Need to Know About Blower Door Testing

We all want our homes to be properly insulated, to keep us cool during the summer and warm during winter. But insulation does not only include lining the walls and roof with thick and soft materials it also includes checking how airtight your home is. Uncontrolled air infiltration as professionals call it is the air that enters your home without you having any control over it. It's not like you opened a window and a little bit of breeze came in.

These are air leaks that occur over a long period of time due to old doors, holes in the cabinet, power points and even recessed lights. Although your door is shut there can be a tiny gap through which air is entering your house. Of course, this can't be sealed hermetically however it can be corrected. But how do you uncover air gaps in your home in the first place?

Blower Door Testing Explained

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What is it?

Blower door testing is a process in which a home is tested for any air leaks by using what is called a blower door. This test is done by certified professionals and with the help of a blower door tester, a door much like any other that comes with blower door test equipment such as a fan, pressure gauge, and airflow manometer.

How it Works

1. The blower door test is done by first shutting off any devices that would have an effect on it, like bathroom fans and HVAC systems. Then the blower door tester is mounted on an external door frame and its hoses are connected. This way the outside and inside air pressure as well as in the fan assembly are all measured.

2. After that the fan in the door starts blowing air out of the home which depressurises it to set a standard in regards to the outside. As the air s pulled from your home it gets replaced by new air which is coming from the leaks in your house. The airflow through the fan is measured and run through a formula that has the dimensions and volume of your home. This then helps determine the air leakage.

Single vs Multi-Point Testing

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You can get either a single or multi-point test performed with the former allowing the operator to do a single measurement by removing pressure up to 50 pascals. With the latter, the operator is able to do a few readings at a pressure up to about 60 pascals. Multi-point blow door testing is done to identify tricky air leaks and thus it requires the use of more blower door equipment.

How to Prepare for Blower Door Testing

To get your home ready for a blower door test you need to turn off combustion appliances as otherwise, you would bring carbon monoxide in your home. This is because the test together with the blower door equipment causes them to backdraft. If you have a fireplace in your home make sure to turn it off and clean any ash left over. The operator will also expect you to do a walk-through of your home in order to point out some well known drafty areas. 

Expect the test to last about an hour. The operator (auditor) is also going to open all interior doors and close exterior doors as well as windows. Do expect the operator to set controls on all atmospheric fossil fuel appliances in your home. This is done to ensure that they do not fire while the test is taking place. They are going to be returned to their original position once the test is over.

Tips to Make Your Home Airtight

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DIY

Improving the airtightness in your home should always start from you and the first best thing to do is apply new caulking around any drafty windows. You can also use expandable caulking to seal any gaps behind a drafty baseboard. Make sure to also replace rubber sweeps at the bottom of your exterior doors to ensure a tight seal.

If your home has leaky doors, it's best that you install new weather-stripping. You should also consider placing insulating foam gaskets being switch covers and outlets to block any drafts. Experts also recommend installing a louvred vent cover on your stove vent in order to block any backward airflow coming into your home.

Professional

In case your windows are loose and old in the frames, caulking won't really help that much. You should instead consider getting installed energy-efficient windows. If your wood-burning stove or fireplace is drafty even when you have them closed you should contact a chimney repair company to come and seal the air leaks around them or replace the flue if needed.

Conclusion

A drafty home is one that is not energy efficient since a lot of the time cooling or heating appliances are working double-time to keep your home cool/warm. By keeping your home as airtight as possible you can expect to pay less on your next utility bill and ensure that no appliance gets overworked. This in turn also saves you money on getting new appliances more often.