Whether they are called canister lights, down lights, pot lights, or can lights, recessed lighting fixtures have become a popular feature in many homes today. Though believed to have been invented as early as the 1930s, recessed lighting has seen a boost in popularity over the past two decades, thanks in large part to the housing boom. Manufacturers like Seagull, Lightolier, and Juno tout these styles as “clean”, “modern”, and an “efficient use of light”. But with their popularity has also come concerns over their safety and effect on the durability of other components in the home.
Recessed lighting fixtures are made up of three parts. A canister (hence the term can light) that houses the wiring components and the bulb is located behind the drywall. A trim kit, coming in various styles from low profile to “eyeball” is then installed flush with the drywall to complete the fixture. The last part, not surprisingly, is the bulb itself.
Can lights have been referred to as “down lights” because of their overall purpose. The fixtures are designed to direct the light in a specific direction, usually straight down. Think of the way a flashlight directs the light ahead in a wide “beam”. For this reason, manufacturers describe it as an “efficient use of light”. It has no effect on energy consumption, but is rather a way to illuminate a specific area effectively. In many cases, directional trim pieces can be installed to highlight wall art, furniture, or a specific portion of the floor plan.
Recessed lighting in this fashion, for all the positive aesthetics and visual appeal, also present a legitimate energy efficiency and safety hazard. The canister portion of the light fixture comes in two styles; IC and non-IC rated. IC stands for Insulation Contact and denotes whether the fixture can be installed such that insulation is in direct contact with the canister. Non-IC rated cans typically require a minimum of three inches clearance in all directions.
Traditional incandescent bulbs get very hot during operation, as anyone who has tried to change a blown bulb a little too quickly often finds out. Because halogen bulbs are popular with recessed lighting fixtures, the temperature within the canister can get even hotter. Traditional, non-IC Rated cans rely on natural conduction and convection to dissipate the heat. This means that the canister itself can get quite hot, and releases that heat to the surrounding air of the space in which it is installed. If insulation is installed directly in contact with a non-IC rated can, it can be a fire hazard. Newer, non-IC rated cans often come with a temperature sensor that turns the fixture off automatically when temperatures over a certain limit are detected. So important is the issue, that the International Association of Electrical Inspectors has issued specific guidance on inspecting these fixtures.
IC Rated cans are designed to be buried within the insulation. This style, though, are not without disadvantage as well. These cans are traditionally larger than non-IC cans making the installation in some applications unrealistic.
For those interested in energy efficiency, IC Rated cans may not be so appealing. In order to allow the fixture to be surrounded by insulation, IC Rated cans are designed with specific “vents” that allow heat to escape the can. Unfortunately, where heat escapes, so does air. And those vents are open whether the light is on or not – meaning each recessed light is a small hole in the thermal envelope of the structure. Imagine taking your favorite sweater and cutting five or six one-inch holes in it. That sweater wouldn’t perform nearly as well as it had before you cut it.
Recessed lighting that is both “air tight” and IC-Rated are available, as more and more consumers become aware of both the safety and efficiency issues surrounding these fixtures. As the country focuses on energy efficiency, and the benefits of air sealing and insulating homes becomes more published, recessed lighting has gotten a lot of attention. The Department of Energy’s resource for homeowners, energysavers.gov even has a specific section on recessed lighting and how to properly address fixtures when insulating.
For those with a budget that will not allow for the replacement of non-IC rated cans, all hope is not lost. Recommendations range from replacing the bulbs with fluorescent styles that generate far less heat to ensuring that insulation is kept away from the can housing by constructing a “box” of non-combustible material like metal or drywall. This way insulation can be installed over and around the box, helping to shore up the thermal envelope.
Regardless of the strategy, from a safety and efficiency standpoint, attention should be paid to recessed lighting fixtures. New construction and retrofit projects alike require evaluation of all aspects of the project, and how each piece will interact with the others. Fortunately, as more and more attention is paid to issues such as these, technology abounds that allows for a safe, efficient, pleasant way to light our homes.
Weatherization Assistance Program Technical Assistance Center, 2011. “Standard Curricula, Installer: Typical Weatherization Measures”, Department of Energy. January 10, 2012.
Energy Efficiency and Renewable Energy, 2010. “Tips for Sealing Air Leaks”, Department of Energy. January 10, 2012.
Margerison, Darren. “Proposed New Standard Covering Downlights” IAEI Magazine, January 7, 2008 International Association of Electrical Inspectors. January 9, 2012.
O’Boyle, Michael. “Installation Clearance Requirements for Recessed Luminaries” IAEI Magazine, July 15, 2001. International Association of Electrical Inspectors. January 9, 2012.