Last February we had the opportunity to photograph our house with a Fluke infrared camera. For those that don’t know, the infrared spectrum is more commonly known as heat. Thus infrared cameras are very helpful to pinpoint where a building’s heat loss is coming from. The outdoor temperature on this particular day was was around 28 degrees F and the indoor temp was around 65.
Our house looks pretty good in the infrared images. As expected, the walls are uniformly reading exterior temperatures. On the left image, one can see a reading of 40.9 d.F. with a streak of heat tailing upward. This is heat loss from the bathroom vent. Overall, I am disappointed in the leakiness on the duct hoods. These are models available through EFI, which ordinarily sells higher quality insulation and building envelope products. I suspect there just aren’t better ones readily available. As to be expected, one can make out a fair bit of heat loss around the windows and doors. The windows on the left image are both triple panes from Serious. The closer one is a single hung unit, the farther a casement. The south-facing glass door in the image on the right shows a fair bit of heat loss. The picture window to the right of the door is a Serious fixed triple pane. The one to the right of the picture window is a double pane, double hung Anderson, and the two above are both Marvin; also double pane double hung. On the right image on the second floor wall one can see the intake and exhaust duct hoods for the HRV. The readings indicate we are taking in 25.4 degree air (the lower hood) and exhausting 30.3 degree air (the upper hood).
For contrast, here are a couple of infrared images of our neighbor’s home. One can see a lot of blotchiness in the house indicating heat loss. Framing members are visible, and as are under-insulated wall cavities. The window on the bottom middle of the left image is a single pane only, and is clearly conducting out a lot of heat as it reads almost 45 degrees F.
Here is an infrared shot of our Mitsubishi Ductless minisplit. The ambient temperature is around 26 degrees, meanwhile, the minisplit is at 19.1. The 7 degrees of difference represent the heat that is being used to heat our home. It is also interesting to see that the minisplit is creating a localized cold spot on the ground in front of it where the temperature reads almost 4 degrees cooler than ambient.
This is the northwest corner of our house. The house is on slab with R20 under it and R32 vertically along the foundation stem wall. The mudroom, which is sealed off from the heated part of the house. Corners are typically the cooler locations in a house.
Another corner of the house. This is the second floor south west corner.
This is one of the air supply registers from the HRV. We saw a 5 degree difference in exterior air temperatures on the HRV, and we are seeing a 13 degree difference on the interior air differences. I am having difficulty thinking about whether or not these differences are supposed to be the same.
This is a picture looking up at the cathedral ceiling of the master bedroom. This ceiling is the under side of our parallel chord trusses that are insulated with dense pack cellulose. Interestingly, this is the only place we were able to see hints of the framing. Looking carefully, one can just make out a truss where I put the 61.2 temperature marker. I wonder if the reason why we can make it out at all is due to the fact that the topside of the cellulose is exposed to the ventilation plane under the roof. It isn’t really a concern though, the camera is very sensitive, and the difference in temperature is nominal. The hot spot in the picture is one of our CO/smoke detectors.
This is a photograph of where the ceiling of the mechanical room meets the exterior wall. The ceiling is made up of 2×6 T&G floorboards that extend through the wall to a ledger attached to the exterior set of 2×4’s of the double stud wall. The mechanical room can get significantly warmer than the rest of the house due to heat radiation from the solar hot water tank and hot water pipes.