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drafty windowAs colder weather begins to set in, furnaces across the continent start firing up to keep us warm. A good furnace keeps the temperature cozy and warm throughout your home… except for the places it doesn’t. Drafts are the bane of cold weather heating efficiency, seeping away the air you’ve paid to heat and creating cold spots throughout your home.

How to Find the Source of Your Draft

Repairing drafts in your home is fairly simple. Updating insulation, sealing gaps and cracks, installing weather stripping, and updating your windows, are easy solutions for fixing costly air leaks. While most of the solutions to a drafty home are straightforward, locating the source of cold drafts is a bit more complicated.

Feeling for Drafts

Windows and doors are the most common locations of a drafty air leak. You can easily check around doors and windows for leaks when it is cold outside and the heat is on. Simply move your hand around the edges of outside doors and windows and feel for cold air.

Feeling for cold air is the simplest way to check for significant air leaks. Be aware of any cold spots as you walk through your home. Besides windows and doors, mail slots and pet doors are two other areas that should be checked for drafty air leaks.

Leaks that are located around pet doors and mail slots are tricky to fix. Often the only solution is to have the openings completely sealed.

Other Ways of Detecting Leaks

Some drafts are difficult to detect by feel alone. To detect subtle air leaks, you can use a low-tech tester for assistance. A common household candle is the simplest tool for locating the source of drafty air, and most homes have them already on hand.

First, turn off your HVAC system. Then simply light a candle and walk slowly through your home while holding the lit candle. If the flame of your candle flickers, you’ve detected a nearby air leak. Use the candle to trace the air flow to its source.

Another highly effective tool is a draft detector. Available in most hardware or home improvement stores, a draft detector emits a thin stream of odorless smoke. By observing the movement of the stream of smoke, you can find the source of moving air.

Calling in the Professionals

If you problems with serious air leaks, or if you are having difficulty pinpointing draft sources, it’s time to contact an HVAC or electrical specialist.

Thermographic Imaging

A professional technician can perform a household energy audit with high-tech thermographic imaging. With the use of handheld devices, a special technician can detect heat patterns in your home.

With this technology, cold spots will stand out on the display screen even if there isn’t any significant air movement. Drafts around vents, electrical outlets, and recessed lighting may only be detectable with thermographic imaging devices.

Blower Door Pressurization

A thorough household energy audit usually involves a blower door pressurization test. This is the most thorough way of testing your home for energy leaks.

During a blower door pressurization test, a trained technician will close the windows and doors of your home, except for the front door. A door-sized panel is sealed against the open front door, and a large fan is activated to pull the air out, depressurizing your home.

With the indoor pressure decrease, drafts become easier to detect during an interior inspection. This method is most effective for locating air leaks in attic and basement areas. These areas are the most common locations of drafty leaks, but are also the most difficult places to pinpoint drafty sources.


If you suspect your home would benefit from a professional energy audit, or if you need help locating drafty areas in your home, contact your local HVAC professionals to schedule a consultation.