Where heat and cold escape: what a thermal scan shows
In winter you pay to heat the air inside; in summer you pay to cool it. Some of that air leaks out through gaps you cannot see. A thermal camera makes those places visible, as temperature differences on walls, ceilings, windows and doors.
What the camera sees
A thermal camera shows surface temperature as a picture. On a cold day, a spot where warm air escapes, or where insulation is missing, looks different from the wall around it. On a hot day the pattern reverses: where cool air escapes from the house or hot air pushes in, the surface stands out the other way.
“Thermal imaging with an infrared camera helps identify heat and energy loss.”
“Assessors use the images to determine the location of air leaks.”
The Department of Energy guide describes the same thing in more detail: the differences show up in the image as warmer and cooler areas, along walls and roofs and around windows and doors.
Where heat and cold commonly escape
- the attic hatch and the top-floor ceiling
- around recessed lights
- gaps around pipes, ducts and the chimney
- around window and door frames
- walls where insulation is thin or has shifted
What a thermal scan cannot tell you
- It shows where heat moves, not how much a fix would save.
- It needs a temperature difference between inside and outside to work well.
- A cool patch can also be water — so a spot that looks damp is checked with a moisture meter before anyone calls it an air leak or a water leak.
A camera scan is one tool, not the whole evaluation
The DOE guide describes the infrared scan as one of the two most common techniques in a professional energy evaluation. The other is a blower door test: a powerful fan lowers the air pressure inside the house, so outside air is pulled in through unsealed gaps. When the two are done together, the guide says, air leaks show up as black streaks in the infrared image. Our thermal imaging is a camera scan only — it does not include a blower door test, and it does not cover heating and cooling equipment.
When a scan shows the most
The larger the difference between the temperature inside and outside, the clearer the picture. A scan for heat loss is most useful on a cold day with the heat on; a scan for cool air escaping, on a hot day with the air conditioning running. Conditions on the day change what the camera shows, so the date, the time and the weather are written down with the images.
What we offer
We offer thermal imaging for heat or cold loss as an add-on to a leak or moisture visit, or on its own for a building — common areas, units and the top floor. You get the images and our notes on where heat or cold appears to escape. We do not sell insulation or air sealing, and we do not estimate savings.
In a building, the same scan can compare floors and units: a top-floor ceiling, a stairwell, a row of windows on one side. What to fix — sealing a gap, adding insulation, adjusting a window — is a separate decision. The DOE guide puts it the same way: after the findings, you decide which improvements to make.
Managing a building with 4 or more units, or a commercial property? See our property program.
This guide is general information for homeowners and property managers, not an assessment of a specific building.
Sources
- NYSERDA — New York State Energy Research and Development Authority, “The Complete Guide to Home Energy Assessments”
- U.S. Department of Energy, Energy Saver, “Consumer Guide to Home Energy Assessments” (PDF)