Tim Gould
Many homes these days have recessed lights that are contributing to significant heat loss in the winter months. Recessed lights are lighting fixtures that are embedded in a ceiling with the face of the light flush with the ceiling. The great majority have holes in the fixtures to allow for air to flow through. Heat loss typically goes unnoticed by the homeowner because heated air is going one way — out of the house. However, sometimes a drafty condition is noticeable. One homeowner for whom I conducted an energy audit complained that it was so drafty that her newspaper was blowing when she sat reading in the middle of her single-story living room — which contained 28 recessed lights.
Recessed lights contribute to significant heat loss because they are often at the top of the house, typically in an attic that is converted to living space. As described in previous articles, the stack effect dictates that as it gets colder outside, heated air is forcing its way out at the top of the house at a greater rate. Holes in recessed lighting fixtures make for little chimneys, easily allowing heated air to escape. Even a few can make a significant contribution to higher energy bills, but when there are many recessed lights, it can add up to hundreds of square inches of area open to the outside. One home that I recently audited had more than 40 recessed lights. A total of $613 per year in energy costs was ascribed to air leakage, of which a significant portion was attributed to the recessed lights.
Recessed lights can be either replaced with air-tight fixtures or they can be sealed. Replacing with air-tight and Insulation Contact fixtures not only prevents air leakage, but allows insulation to be in contact with the back side of the fixture. Additionally, there are now air-tight inserts or trim that fit into some recessed lighting fixtures so that the fixture, or can, does not have to be replaced. It is important with any air-tight fixture to seal between the trim and the ceiling surface with a gasket provided by the manufacturer.
When recessed lights are open to an unconditioned attic, it becomes an option to seal non-airtight fixtures rather than replace them. If the fixtures are not IC, then most building codes require that any insulation be more than 3 inches from the can. A box made from non-combustible material can be built and placed over each light, then sealed so that it is airtight. Insulation can be placed over the box.
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Tim Gould is director of Energy Egghead, an Amesbury-based company that can be found at www.energyegghead.com, and provides professional energy audit and conservation services.
