Seeing red about heat loss
Infrared cameras find heat loss in your house
Kristy Dyer - Nov 3, 2026 4–5 minutes
When I purchased my house, I paid a registered energy advisor to do an energy audit.
The report was highly accurate but, I confess, the entire time I was itching to play with the infrared camera myself. Now, in the Okanagan, you can borrow an IR camera through your local library and that’s what I spent two days recently doing. It has to be a minimum of 10 C between the outside and the inside of the house to get good contrast, so our 1 C nights and 20 C indoors was perfect.
Ideally, from an insulation perspective, your house should be a sealed box, with no windows and no doors. That would keep the cold air out and probably you as well.
Modern doors can be very energy efficient but windows are always a trade off. We love the natural light and the view but even the best windows don't insulate as well as a wall. However, that's no excuse for windows or doors that leak around the edges.
In the top figure you can see my old fashioned door with a mail slot. I recently fixed the weatherstripping so you don't see cold air leaking around the edges so, but you can see that the door is colder than the walls. The fanlight at the top is double pane and the brass mail slot might as well be open to the elements.
The second figure, however, is the killer. It is a photo taken from outside, first thing in the morning and shows heat coming from a window but much more heat emanating from the dirt-floor crawl space.
I have a house with old windows, old doors and old attic insulation but what is blowing me out of the water, and blowing up my electricity bill, is my uninsulated crawl space. The picture is horrifying and no easy fix.
I went back to my NRCan Energuide report to see what the professional told me. The weakness of doing my own inspection with an IR camera is IR images focus attention on differences, rather than absolutes.
I could have a supremely energy efficient “passive” house and the windows would still light up, even though they were triple-pane and very energy efficient. I could have a traditional Japanese house, with walls made of sliding paper screens and a thatched roof, which might look uniform—uniformly uninsulated.
The renovation upgrade report provided absolutes. My house uses 1.06 gigajoules per meter squared per year. I can compare that to a neighbour’s home to see where my house stands.
It also shows room for improvement. Currently, I’m at 72 gigajoules per year and if I follow the recommendations, I could get to as low as 26 gigajoules per year. What were the recommendations?
1. Perform air sealing.
2. Insulate foundation.
3. Insulate main walls.
4. Upgrade heating system (electric baseboard).
What did I do? I cheated. I upgraded the heating system to a cold-weather heat pump so I could have AC during the summer. I’m not alone in this. Summer heat waves are driving Canadians to heat pumps.
Then, as suggested, I set about working on air sealing. I put cute little foam cutouts behind all the electrical outlets and lightswitches on exterior walls. When we replaced the baseboard, I used caulk and spray foam to prevent air from sneaking up from the crawlspace where the floor meets the walls. I also weatherproofed the edge of one exterior door.
I’ve checked over the house with my nifty IR camera. Neither my baseboards, nor my electrical outlets show up. There are leaks around the door I didn’t weatherproof but the heat transmission through the crawl space is a killer. It’s right there, No. 2, on the list I got from the professional but it took an IR photo to drive the point home.
IR cameras can also find blocked HVAC vents, water leaks hidden in dirt or behind walls (wet places show up a cool spots) and overloaded circuits in your breaker box.
There are more photos of both my house at my blog teaspoonenergy.blogspot.com and, as a bonus, there are also IR pictures of my cats.
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