Infrared technology isn’t new. FLIR, the company that produces the camera that we use at F.P.D., has been making quality cameras since 1978. Infrared technology is used by law enforcement during surveillance, the Coast Guard during search and rescue, airport authorities attempting disease control, and home inspectors looking for a variety of issues in homes both new and old.
Thermal infrared radiation (IR) is the heat that all objects radiate. Although we can’t see it, it’s part of the electromagnetic light spectrum; just to the right of the visible light that we can see and to the left of microwaves and radar.
Home inspectors who are trained and certified to use an IR camera are recognized as infrared thermographers. Like any tool a home inspector uses, IR technology has both positive applications and limitations. Most home inspectors are using IR cameras that will take two photos simultaneously. FLIR calls this their MSX technology. One photo captures the IR and assigns different temperatures different colors. The second photo is a standard visible light digital image. These two photographs are combined to show clearly where the anomalies are.
What is a thermal anomaly? A thermal anomaly is something that deviates from what is standard, normal, or expected. To the residential thermographer, it’s something that is warmer or cooler than expected and a variation to the surrounding similar material. It’s the clue that the inspector uses to draw him in for a closer evaluation to validate what the camera is indicating.
During a home inspection there are many uses for IR technology and for thermography. Detecting and photographing water intrusion is the most common. When I scan a room I’m used to seeing an array of colors. Inspectors have varied preferences for what color mode they scan in and set their cameras to display these. My camera is set to display cooler areas in blue and warmer areas in red. I think that fits most people’s understanding of temperature and to make my reports as clear as possible that’s what I film in. At times a room can look like a rainbow. Sunshine coming through a window and warming a wall will make that wall appear a shade of red and turning the cooler wall next to it a shade of blue. The air conditioning vent in the ceiling may be blowing much colder air turning it and the ceiling an even darker color blue. An experienced and well trained thermographer knows how to interpret all of these variations and how to interpret the occasional thermal anomaly, like a blue area at the top of the red wall, which indicates possible water intrusion. Only about half of all home inspection companies use IR on inspections. Of those most only scan wet rooms for plumbing leaks. At Florida Property Detectives, we scan the entire house with IR because water can be anywhere. It can come from a roof leak, from poorly sealed doors and windows, from plumbing and from the HVAC system.
Energy efficiency issues are also often found by an IR equipped home inspector. The lack of insulation in the ceiling might be seen from the attic, however the lack of insulation in walls is something that’s almost impossible to find without IR. This often happens when insulation collapses in older homes leaving gaps in the upper wall without insulation. Even in brand new homes builders will occasionally neglect to insulate a wall entirely. These issues show up as thermal anomalies that are red in the summer (hotter than the rest of the wall) and in colder climates, blue in the winter (colder than the rest of the wall). Regardless of the climate and the color, the problem is the same: the home is using more energy than it should, costing the home owner additional money.
The electrical service panel can also be evaluated with an infrared camera. Overloaded circuits and breakers are easy to identify during an IR scan.
Infrared cameras do have limitations. They can only measure surface temperature, they cannot see through objects. They also need a temperature difference to identify a thermal anomaly. An example of this is if the outside and the inside temperature are both 72 degrees, the temperature of the wall, weather insulated of not, won’t be different so the infrared camera won’t detect any missing insulation.
IR technology on home inspections is here to stay. You’ll still occasionally find an inspector who will try to convince anyone who will listen that IR is a waste of time. I think what they’re doing is justifying not spending the thousands of dollars it takes to buy a quality camera and to get the appropriate training. The best inspectors will always use the best tools available to provide the best inspection possible. This includes infrared technology. Insist on it.