Thermal Imaging of Home Energy Loss: Uses and Limitations

Sean Moss
February 25, 2016

According to a recent 24 Hours report, the City of Vancouver will be taking thermal images of thousands of older Vancouver homes as early as April 2016. The goal is to compile information from these readings to help educate respective homeowners about heat loss and the impending side affects of greenhouse gas emissions on our environment. Similar experiments have been conducted in a number of US cities with great success, so Vancouver has jumped on the bandwagon. As a point of reference, the term “thermal Imaging” can also be called “thermography” and “infrared”, which have been used throughout this piece.

Essentially, thermal imaging can be used specifically to see what the eye cannot when it comes to identifying heat loss through voids in buildings. Older homes will be targeted for this project because heat loss and energy efficiently was simply not a priority when these homes were built; nor did the impact on the environmental matter.

Technological Limitations

This technology does not come without its limitations, however. It cannot see through walls like many people have been led to believe. To be most effective, there must be a temperature difference of at least 15 degrees, especially when looking at exterior walls. They are not useful for finding problems with voids, and missing insulation during the summer and during daylight hours. This is one of the reasons why the article pointed to conducting these readings on cold nights, as the outside temperature is cool compared to the inside.

In addition, the 24 Hours report suggested that this technique was used successfully in several US cities, but does not state which cities, nor at what time of year they were taking the readings – two very important considerations for the use of this technology.

Overall, when considering the stated limitations, and used appropriately, this directive can make sense for homeowners, city planners and builders. The findings can demonstrate to how much heat Vancouver homes are actually wasting during this experiments, while solidifying the city’s resolve for lowering greenhouse gas emissions.

Thermal Imaging in Home Inspections

From the point of view of a home inspector, thermal imaging can be used to help homeowners understand where heat loss will impact them personally and financially so they can make the necessary improvements for low cost, comfortable living.

Below I have listed how home inspectors use thermal imagining during a home inspection and when the application is either effective or unnecessary.

Locating missing insulation in walls: The conditions have to be ideal for this application to tell you any meaningful information. As stated above, the temperature on the tested surfaces must be at least 15-degree difference from the inside to the outside. Home inspections are not typically done during the evenings. Further, the use of Thermographic cameras would be limited to exterior walls only. For our climate this should only be done in the winter.

Diagnosing problems with in-floor heating: If you want to test the in-floor heating in the summer, it will take several hours for the pipes to heat up. Once the floor is warm, the application can show any flaws or leaks, but the home will be uncomfortably warm until it cools down several hours later. Most people turn off the heat in the warm season; so again, I would wait for the winter before using the thermal imager.

Locating rodent activity: This is usually discovered by spotting insulation voids in the attic and is essentially the same as locating missing insulation in walls. It is best used in the winter, when rodents come into the home, and during the evening when they are most active.

Finding electrical issues: The thermographic camera can be used anytime for this to work properly, unless the power has been turned off. You will be able to see circuits or receptacles are running too hot, which is an excellent preventative measure for reducing electrical fires. This practice has and will continue to be used in large and small commercial buildings as well.

Finding air loss around doors and windows: Improperly installed windows and doors can be drafty, which costs homeowners money. As mentioned above, the outside weather should be cooler for this to be effective. However since we would be dealing with air loss, it can done in the spring or fall as well. This application is actually best when used by an energy advisor. Energy advisors conduct energy audits to show homeowners how energy efficient their homes are. They put the homes under negative pressure to pull air through gaps, thus revealing air leakage. For the camera to see this, ideally it should be set to a grayscale colour palette, or what we would see as black and white.

Locating leaks and or moisture issues: Water retains hot and cool temperatures for long periods of time, so this is one of most useful applications a home inspector can employ to pinpoint the source of internal plumbing, exterior or roof leaks. 

Should I Ask My Inspector to Use Thermal Imaging?

When considering the service of infrared scanning, the home inspector should be at minimum, a Level 1 Certified Infrared Thermographer (trained in the applications of thermal imaging, interpretation, and analysis of what the camera displays). These cameras are complicated, sensitive instruments to help your inspector properly scan the home, detail vulnerable areas, and describe what may or may not need to be addressed.

In addition, with a new focus on higher energy efficiency standards and green building practices, homeowners will be encouraged and offered rebate incentives to ensure that their homes meet or exceed these standards.

As the demand for this technology grows, the cost of acquisition will decrease, which is good news for individuals looking to harness its capabilities. Thermal imaging is quickly becoming not only standard practice, but also an integral technology for scientifically bridging the gap of understanding between the impact of heat loss, energy efficiency and environmental impact on our society for future homeowners and builders. However, as with any technology, it must be used appropriately, given the right set of circumstances and by a properly trained technician, or you could be spending your money needlessly.

Before investing in an infrared reading of your home, be sure to properly qualify your inspector, understand the limitations and know what application(s) the camera will be used for.

Sean Moss
Sean Moss is a home inspector focusing primarily on residential properties with specialized knowledge in mold and building envelope science. He has been featured in Vancouver Magazine, Richmond News and The Jewish Independent and he also shares his knowledge through articles and workshops. Call Sean on 604-729-4261, visit his website and see his rating on review website HomeStars.