While many people are well aware of the energy loss that occurs around windows and doors, few recognize that electrical boxes for wall switches, outlets, phone junctions, and other devices add up to a surprisingly big energy drain. If you closely examine electrical boxes located on exterior walls or walls that face unheated spaces, you can often feel cold drafts coming through the box or around the edges of cover plates. And although you don’t feel it, these boxes are also spots where you are losing air-conditioned air to the outdoors during the cooling season.
The reason for this is simple. Even if a wall or ceiling is sufficiently insulated, the insulation may have been cut away to make room for the electrical boxes, which means these spots become conduits for air to pass through. And on walls where there is no insulation or insufficient insulation, air circulating inside the wall finds a perfect pathway into living spaces through the electrical box cutouts in the drywall or plaster. In winter, this becomes a source of indoor heat loss, and in summer, a source of heat gain from the outdoors.
Fortunately, correcting the problem isn’t difficult. It involves adding insulation where you can and sealing air gaps around electrical boxes. There are three common methods for insulating electrical boxes.
Source: The Spruce
