If you've ever noticed cold air leaks while plugging something in, it might be time to insulate outlets in your home. Both electrical outlets and light switches have the potential for air leakage if not properly sealed. While the amount of air seems tiny, it can definitely add up on your energy bills.
Air gaps are energy drains
If you’ve taken off the cover plate on the outlet switch, you've probably noticed a space in the wall where you can store a power outlet. This unused space in the exterior wall lets the airflow in from the outside with or without the cover plate attached.
Foam outlet insulation
One solution to leaky outlets is to use foam gaskets. These gaskets fit underneath the cover plate and extend beyond the edges to prevent airflow. Some homeowners use spray foam insulation as an alternative to gaskets.
Whether you choose spray foam or a foam outlet gasket, this is a common and affordable way to seal the gaps.
Sealing junction boxes
While foam does make a difference, the most efficient way to prevent warm air from moving in or out of your walls is to also seal the junction box. You can do this by using spray foam inside the empty spot behind the cover plate. Make sure to use non-expanding foam, as expanding foam can be a fire hazard.
This is only a basic guide to air seal electrical boxes at home. Always turn off the power before tinkering with your outlets, and consult a licensed electrician for guidance.