Air Leakage Around Recessed Canned Lights

If you have had an APS energy audit or SRP energy audit performed on your home, the auditor probably showed you the blower door readings or thermal images of your canned lights. These are notoriously leaky, and if a smoke pen is held up to the light, you can see the smoke gets easily sucked right up into the attic through recessed light.  If your home has more than 10 of these recessed lights, it can be a significant source of air leakage in your home. The average home wastes about $5 to $30 per year, per recessed light, so it is an important cost savings consideration and health and safety concern if moisture escapes into the attic as well. Here is a little background on these lights and what you can do to stop excess air leakage in your home.

Recessed lights are typically installed in areas of high traffic areas like kitchens, hallways and family rooms. Canned lights are either IC rated, insulation contact rated, or non IC rated, which cannot come into contact with insulation. If additional insulation has ever been added to your home you may want to check that the insulation contractors put some sort of protector around the light before blowing more in. Typically in homes built before 1995, non IC canned lights were used, but I have seen plenty of newer homes with non IC rated canned lights installed. You can find out if your lights are IC rated by going in the attic and looking at the nameplate of the metal light. There is usually a label glued on top of the light that says the specifications of the light and it will say, “IC Rated”. 

Recessed lights in a two story home can also contribute to the stack effect if there are enough lights in the ceiling. The stack effect is when warm air rises and is replaced by cool air entering the home through outside penetrations and duct leakage. The stack effect and air leakage can be stopped by air sealing the home including the canned lights. To find more information on how canned lights can contribute to the stack effect in your home check out this article by the Pennsylvania Housing Research Center.

There are several ways you can effectively seal your canned lights, by either replacement or retrofit. Replacement options can be done with air tight LED lights or air tight recessed canned lights. Both replacements are very effective, the advantages of LEDs are a longer lifespan, are fully dimmable, and use less energy. Replacements done with air tight recessed lights are also very good. I recently performed an energy audit on a home built in 2006 that had the new air tight recessed lights and can verify that the leakage of the light is very low. The reading from the canned light you see on my manometer is 0.9 Pa and a typical canned light measures at 40 Pa, which is a lot of leakage.

The other option is to build energy lids with at least 3-inches of clearance between the light and the box. The energy lid can be fitted over the canned light and sealed at its edges. Warning! Do not use expanding foam to seal a canned light; the foam can drip down into the house and on the trim. The energy lids can be effective if you have non IC rated recessed lights and need to add more insulation to your attic. You can view more tips on how reduce your energy bills here.

For a guide on ways to seal up your home check out Energy Star’s publication on air leakage and air sealing your home.