In my last blog post, I described how the infrared camera I borrowed from Charles Robertson helped me see where some of Kendal’s cottages are losing their heat. That was done by photographing them from the outside.

But infrared photography can be equally useful indoors. It can show you precisely where some of your heat-loss problem areas are. In this post, I’ll share what the camera told us about our cottage.

It’s important to note that our cottage was gutted to the studs and totally refurbished before we moved in, less than two years ago. It should be (and probably is) one of the best-insulated cottages around. But it still has plenty of problems, and that suggests to me that every cottage could stand some improvement. (I’m not sure that this applies to the “new” duplex cottages, built in 2012 to LEED standards. I have not investigated them.)

We wanted to see where cold air was getting into our cottage. To do that, we turned on the exhaust fan in our bathroom and powder room, turned off our heat, and turned off the blower that circulates the air. The idea was that the exhaust fans would suck outdoor air into the cottage, and the infrared camera would show us where that was happening. (Note that not all of the heat loss from our cottage is just from outside air coming in. Almost certainly, some heat is lost from radiation of our cottage’s warm surfaces to its colder surroundings and from direct heat flow from the cement slab our cottage sits on, neither of which involves the flow of air.)

As with my outdoor investigations, we found some things we expected and some we didn’t.

Doors and windows. Of course, doors and windows were major culprits. Our cottage is a bit unusual, having been assembled from what was previously two apartments, a one-bedroom and a studio. It has both the patio that was part of the studio and the 3-season room that was part of the one-bedroom. That means we have sliding glass doors for both our patio (outside our bedroom) and our 3-season room (outside our living room/dining room). They both let in a lot of cold air. Here’s a picture of the area where the two sliding halves of our patio door meet. Although the cottage temperature is 73 degrees, and the carpet a few feet from the door is 71 degrees, the metal frame of door itself is 36 degrees. The outdoor temperature is right around 30. Clearly, a lot of heat is being lost here, and cold air is being let in.

The bottom of the sliding door to our patio.

The door to the 3-season room is also cold, but not to the same degree. At the time the patio-door photo above was taken, the metal frame of the 3-season door was about 55 degrees at the base. Not great, but a lot better than 36 degrees.

Our front door leaks too. Here’s a photo showing how the lower part on the door-handle side is quite cold. It registered about 44 degrees at the lower right-hand corner. That’s partly due to the lack of a proper seal under the storm door. We put a work order in for that over a year ago, but then the pandemic hit.

The bottom of our front door, on the door-handle side.

Some surprises. More surprising was the wall leakages we found. The photo below shows a spot where the outside wall (at the left) meets the half-wall that divides our kitchen and dining areas (at the right). The temperature there is only 49 degrees, while the cottage as a whole is 73 degrees. This is probably an example of one of the “sill leaks” that I mentioned in the previous blog post.

A cold spot along an exterior wall. It may be a leak at the sill. A sidewalk abuts the house on that side.

Another surprise was the attic hatch, which is in the ceiling of our closet. It was about 5 degrees colder than the surrounding ceiling, suggesting a lack of insulation over the hatch.

What needs to happen? It is my understanding that more emphasis has been put on heating, insulation, and air-tightness in recent years. Some areas of heat loss in the past, such as the spots where lights are set into the ceiling, are now routinely capped with an insulating dome when cottages are refurbished. Heat pumps are reducing the electricity required to heat many of our cottages. Progress is being made, but (as our cottage illustrates) much more can be done.

All the heat-loss issues noted in this blog post and the preceding one are treatable. Some are relatively easy to fix (like the storm door and attic hatch in our cottage) and some could require a lot of work (like opening a wall to fix a sill leak or removing sections of sidewalk to install insulation around the slab). Ceiling insulation, plus better windows and doors could help with the 3-season rooms.

In my opinion, these issues need to be addressed as part of our obligation to leave a livable planet for generations to come. We need a systematic process of auditing each of our cottages and central buildings, devising a plan to fix the major heat losses, making the needed repairs, and following up with testing to make sure the problems have been fixed. An architect friend tells me there are “building scientists” who specialize in this process. Perhaps it is time to bring one in.

The camera. Here is the infrared camera I used for the images in these blog posts. It is a FLIR i7 camera that I borrowed from Charles Robertson.

Infrared camera, courtesy of Charles Robertson, pointed at our 3-season room door.