Two of the more common complaints we see from homeowners are higher heating bills and being uncomfortable. With that in mind, I wanted to 'shed some light' on a topic very few homeowners know about.
The Problem With Recessed Lighting
The nice thing about recessed lighting is it's unobtrusive, making it popular in kitchens and family rooms. Recessed lights replace ugly ceiling mounts. Sure, you’ve got a neat, uncluttered interior look, but the part you don't realize is you’ve traded a substantial amount of conditioned air leakage into your attic for that appearance. The heat is escaping like crazy – with the trade-off being that you’ve punched a hole through the building enclosure.
Here's the problem they can present. Richard Rue, Chief Engineer at EnergyWise Structures (who has engineered over 40,000 Ultra Energy-Efficient homes), says, "recessed lights that penetrate into the attic space can be the “kiss of death,” unless you’ve insulated the attic with sprayed foam. One of these seemingly innocuous little lights represents 1 square foot of uninsulated attic space, and 20 of them is equivalent to having a door open in the attic at all times".
According to tests conducted in 1992 by the Mechanical Engineering Department at Penn State University in conjunction with Juno Lighting Corporation, the air leakage path associated with a single recessed can light fixture may account for $5–$30 worth of energy loss per year. The same study went on to conclude that a single unsealed can light may serve as a conduit for the movement of about 1/3 of a gallon of water daily into a cold attic. Today’s upscale tract homes may contain anywhere from 20 to 40 or more recessed can lights. Yikes!
Suffice it to say that the air leakage associated with these fixtures is a major problem, and you are certainly justified in pursuing a solution.
Why you should avoid recessed lights to begin with
One Energy Auditor states it this way: "I hate to overstate how problematic recessed lights can be, but… they sure are a pain in the 'energy-auditor' butt. There are worse problems (wet basements), more expensive ones (insulating a complicated roof line), and more frustrating ones (the cross-purposes of energy evaluations and homeowner desires). But few elements of the house combine all three in as tidy a package as recessed light cans."
An Indicator On Your Snowy Roof
The patterns that develop as snow melts on the roof are another clue. When you see signs of snow melt, you should ask this question: Where is that heat coming from? Snow melt patterns can reveal a great deal recessed lights. They reveal where heat is escaping from your home. They point to heat-loss clues.
The Building Science Experts will tell you, not only do recessed can lights leak air, but warm light bulbs also make the situation worse, turning the holes into 'small chimneys'. The heat source accelerates the stack effect, speeding up the flow of air.
The way to fix this situation may be a little more challenging and assuming you have access to the recessed cans in the attic. Recessed light fixtures should be replaced with sealed fixtures whenever possible. Otherwise, only IC (“insulation contact”) rated fixtures should be sealed. The best way to seal these is by building sealed boxes from fire-rated materials such as sheetrock or duct board and covering the fixtures in the attic floor.
Or, you make the installation of an airtight retrofit can assembly a part of your LED retrofit.
The LED retrofits would solve 99% of any air leaks... and the insulation would be to limit heat transfer where I can. Insulating the fixtures may help with heat loss, but using the wrong type of insulation could cause problems in the event of a fire.