Infrared Cameras - Can You Really See Through Walls?

Many people have heard of an infrared camera and the wonderful, amazing things that it can do, but have you taken the time to really find out the truth behind the use of one? You may have heard people claim that they can see what is in your walls or if you have mold hidden in your home; while there is some truth to this, these cameras have their limitations and can’t do all that is claimed. At the same time, they can be an extremely powerful tool, and be used in applications that you would have never have imagined!

To start off explaining an infrared camera, you must first understand a little about infrared (IR). William Herschel first discovered IR back in 1800. He used a prism to refract light onto a table. While he was measuring the temperatures of the various colors, he realized that the temperature on a thermometer sitting outside of the red light was higher than that of one inside the light. Upon further study, he concluded that there was energy above the red spectrum, therefore discovering infrared. Over 200 years later, we have now taken this knowledge and created cameras that can be used by individuals to see this energy.

Put simply, IR is the energy emitted by objects based on their temperature. The higher your temperature, the more energy you emit. Everything in the world emits this energy; however, some things emit better than others - and there are also objects in the world that act as reflectors. This is where the limitations of the camera can come into play. First, the cameras are not able to "see through" objects. However, it does show what is in your walls by way of heat on the surface of the wall. For example, the studs heat up or cool down differently than the insulation, which allows us them to show up on camera. If the insulation and the studs are the same temperature, then they can't be seen. Likewise, the camera will now show mold in the wall; however, the camera may be able to show the water that has caused the mold, because the water heats up or cools down differently than the other objects around it. Also, the camera can't see through objects such as windows, or tell the true temperature of shiny metals or other reflective objects. This is because they have a very low emittance and they would rather reflect your energy than emit theirs.

So you may be asking yourself, "If IR can’t be used to see in my walls, what good is it for my house?" Because objects in the home heat and cool at different rates, and they transfer heat differently, the camera can be used to show subtle differences in the temperatures and draw conclusions from that. Below is a simple list of some of the items that can be investigated around the home with an infrared camera:

1. Whether or not there is insulation in the walls.
If enough of a temperature difference between the interior and exterior can be created, it can be seen (200F or greater is optimum.) The insulation, studs, and voids will show up as different colors or shades, and a thermographer can draw conclusions based on this.

2. Whether or not your have air leaks.
When air movement is forced around the home, with as little as a 50F difference the camera can begin to show the temperature differences caused by this air. This can help with finding air leaks around the home.

3. Whether or not you have an effective air barrier.
While you may not know what an air barrier is, having one is important for efficiency! An air barrier stops air movement through insulation, which increases its efficiency. To get a better idea of its benefit, a leak in the air barrier is kind of a leak around your windows, but it is in the wall, and the air may never enter the living space.

4. Whether or not you have water leaks.
Water heats up and cools down at a different rate that most items in the home. Because of this, the camera can detect the temperature differences between the water and the wall or floor.

These are just a few of the items that the thermal camera can be used for around the home. Depending on the applications, the camera may be able to be used to "see" - or really detect - a variety of items. The cameras are being used in everything from building to electrical to medical. There are a variety of uses for this type of camera! If there is something in your home that you can’t see or wonder about, ask a thermographer - because we might just be able to find it for you.

Use Blinds and Shades for Your Windows

Last week, I touched on replacement of windows and how the payback is so long. This week, I will touch on a simple way to help save energy around your windows. Blinds, shades, and drapes can all help conserve energy. By closing your blinds in the summer, you can help reduce the amount of energy gained through solar radiation; by closing your drapes in the winter, you can help retain the heat in your home. Your window dressings were not made just to look good - they do serve a function, so use them! Also, the bug screen is not just for bugs. By using it you can also reduce the solar gain through the windows.