Our homes are leaky envelopes. We don't notice much–until we get a blast of artic chill as we had in the past few days. I took the infrared camera around the neighborhood to document where the cold air was coming in.
In the first pair of photos here, we see an uncapped air conditioner. Note that the wall of the home was about 29 degrees Fahrenheit (°F), which was close to the ambient outdoor late afternoon temperature that day.
But the porous, unsealed grill of air conditioner itself was much colder–between 14 and 5°F! Why? Wind-chill!
Air is being literally sucked into the house through this gap–literally like having a 2 x 3 foot sponge there instead of a solid wall. Time to get a step ladder, big plastic bag, and some duct tape! Seal up that entire outdoor AC unit!
Inside, starting at the front door, a common cold spot is around the door itself, which can be improved with some simple weatherstripping and door sweeps.
Another common cold spot is where doorframe meets the wall and floor. In this case, the radiator is doing its job, while the cold spot persists where cold in the wall cavity sneaks into the home.
The solution here involves air sealing and insulating the exterior wall cavities of the home with a certified contractor. The state has a good programto help you pay for this kind of home energy upgrade. But there a more spots you can fix on a DIY basis.
Windows are another place where we can make a big improvement with some simple, inexpensive measures, such as painter's tape and rope caulk. One window shown here has rope caulk and shows low reading where the frame meets the sash of 52°F. The window right next to it has not yet been caulked and shows a low of 35°F in the same location.
Another common culprit are exhaust fans. For example, the photo here shows a bathroom exhaust fan below an unheating attic. The fan vents through the roof to the outside. But notice the big cold spot between the joists to which the fan was attached. A trip to the attic revealed that insulation had been pushed aside, probably to make installing the fan easier. The solution is easy, push the insulation back in place!
Another common cool spot is often at electrical outlets on the exterior walls of a home. Simple "outlet insulation" packets are available that you install by unscrewing the face plate of the outlet and slipping between the outlet switch and the face plate. But ultimated these small chilly spots usually mean the wall cavity itself needs to be air sealed and insulated. That is project best done through a certified building performance contractor. As mentioned above, the state Energize program can be a big help is getting a free home assessment and identifying a qualified contractor.