NewburyportNews.com, Newburyport, MA

February 28, 2012

Plugging heat loss caused by recessed lights

Tim Gould

I conducted two audits recently that warrant another discussion of recessed lights and the important role they have in heat loss and dollars wasted. The first was an audit in a North Shore suburban home in which the new homeowners had six recessed lights installed in the living room within months of moving in. Being a Cape, the attic is directly above the first-floor ceiling. In essence, what the new homeowners did to create a pleasant ambiance was punch six holes in their ceiling. The electrician did not serve them well, but rather installed non-air-tight and non-insulation-contact fixtures. And he had to pull the insulation away more than 3 inches from each light for code compliance with this type of fixture. Result: a total area open to the attic of about 6 square inches and heated air leaking out.

The second audit that I did at another North Shore residence, a Colonial built in 2003, had 18 recessed lights on the second floor adjacent to the attic. These were all insulation-contact-rated fixtures (a good start) and had 10 inches of Fiberglas over them, but they were not air-tight. We energy nerds are always telling folks that Fiberglas does little to stop air movement and is effective to its rated R-value only when it is enclosed on all six sides.

So, 10 inches of Fiberglas batt insulation, which is assumed to be about R-30 (and I am being generous), is effectively about R-20 (and I am being generous again). Not only is heated air being pumped through the recessed lights, but the gaps between the Fiberglas and the drywall due to strapping and the gaps between the batts and the floor joists are all causing convective air currents that help to drop the R-value like a lead balloon. Result: a total area open to the attic of about 1.5 square feet, heated air leaking out and reduced average R-value across the attic floor.

Recessed lights have traditionally been costly contributors to heat loss and, thus, deliberately avoided by utility-sponsored programs, such as MassSave. Now, however, there are solutions that did not exist even a couple of years ago that allow homeowners to have all the style of a recessed light without all the energy loss.

One solution is to install air-tight trim inserts. These can be installed by anyone who has a ladder and hands strong enough to squeeze in the spring-loaded recessed light trim. They stop the passage of air through the recessed hole. A second approach is to install new LED (Light Emitting Diode) inserts that seem to fit many larger-size recessed light fixtures. These are more expensive but have an adaptor that allows them to be plugged into any screw-in recessed light fixture. Each of these retrofit inserts will be most effective at becoming airtight when caulking is used between the edge of the trim and the ceiling drywall.

Obviously, because we are talking about lights, it must be noted that significant energy savings can be realized by replacing incandescent lights with Compact Fluorescent Lights (CFLs) or LEDs. Both LED recessed light inserts and new dimmable CFL recessed lights save about 80 percent of the cost of electricity compared to traditional incandescent recessed lights. The price is continually coming down on the LEDs, and dimmable CFLs are getting cheaper. It is important to note that if you switch to these lights, you may have to have a new dimmable switch installed.

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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 intelligent energy solutions for homeowners and businesses. Phone number is 978-388-6349.