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What is the best airtight LED retrofit for can lights?

kevin_in_denver | Posted in Green Products and Materials on

I couldn’t talk the builder out of can lights on the top floor, so I thought I could fix the problem once he’s all done.

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Replies

  1. Expert Member
    Dana Dorsett | | #1

    Bulb size/type= ?

    Best what? Best air tightness, best color rendering index, best dimming range, highest lumen output, best Wi-Fi connection range, or....?

  2. GBA Editor
    Martin Holladay | | #2

    Kevin,
    Is the builder working for you? Don't you have a say?

    Ideally, you would stop the builder in time -- and insist that the electrician install shallow electrical boxes with Philips SlimSurface LED lights. More info here: Rethinking Recessed Lighting.

  3. charlie_sullivan | | #3

    If you are really stuck doing this, the cree retrofits are high CRI, pretty good efficacy, and very reasonably priced at home depot. But I agree with Martin--if you are the one paying him, you should be able to make the decision. If he's paying you for the opportunities to put holes in your ceiling, there might be some room for negotiation, if he pays you enough ...

  4. kevin_in_denver | | #4

    Thanks for the suggestions.

    Here are my preferred specs:

    1. 60-100 watt equivalent
    2. Designed to be airtight, by caulking to ceiling drywall, or taping or whatever.
    3. Dimmable
    4. No wifi or colors or fancy features
    5. Cheapest price.

    Also I am hoping to stuff the existing can with some sort of insulation. I thought there might be a kit out there designed with energy efficiency in mind

  5. charlie_sullivan | | #5

    I don't actually know of any that are specifically advertised as offering air sealing capability. But most can be air sealed by caulking between the trim ring and the drywall.

    It's hard to know what would happen if you stuff the can with insulation. Most of the retrofit modules look like they were designed to dissipate heat into the can. I don't necessarily see a safety hazard from that heat, as most good quality LED bulbs will throttle back the current as they get too warm, and put out less light. Cheaper ones may overheat, but they'd be more likely to degrade or fail from the heat than to start a fire. However, having flammable insulation inside the can could increase the chances of a fire starting upon failure. And the insulation inside the can would presumably violate general provisions of the electrical code.

    If you decide to stuff the can with insulation anyway, I'd advise a surface-mount light designed to mount on a junction box, such as the previously mentioned Philips Slim Surface. Other brands of such things are rapidly proliferating. They would be likely to require less heat dissipation into the fixture. In order to try to make something like that meet code, with the fixture filled with insulation, I start to think of doing things like mounting a J-box inside the fixture, and running the wiring directly to the J-box instead of to the fixture, such that the fixture no longer has any electrical function, and can be safely stuffed with insulation. But at that point, why is the fixture there at all?

    As far as reporting direct experience with specific retrofit modules, I have used the Cree CR6 800 lumen, 2700K, 90 CRI units in a lower-level application where air sealing wasn't necessary. They provide 67 lm/W, which is better than a 67 lm/W bulb, because the 67 lm/W bulb efficacy would be degraded by the fixture optical efficiency whereas the module number is for the whole package. The color and dimming performance, using Lutron LED dimmers, are both excellent.

    Home Depot used to sell those for $20 each, but they have switched to a lower efficacy (50 lm/W), lower lumen (625) unit, the DRDL6, for the same price. But you can get the CR6 elsewhere, for $30. Or you can get the higher brightness, 1100 lm DRDL6 at Home Depot for $25, which has the highest efficacy of the three, 73 lm/W, and could presumably retain similar efficacy if dimmed down to 800 or 625 lm.

  6. GBA Editor
    Martin Holladay | | #6

    Kevin,
    Here is a link to an article that discusses ways to seal air leaks through recessed can lights, and discusses the question of whether it is safe to stuff a recessed can with insulation: What To Do With All That Recessed Lighting?

  7. jackofalltrades777 | | #7

    Can lights are of the devil. If your builder won't listen and still insists on installing them, then he made a pact with the devil and is one of his minions.

    In all seriousness, builders tend to be stuck in their ways and are creatures of habit and difficult to change. In the end, they work FOR YOU, not the other way around. So tell them NO and if they don't like it, find another builder.

    Sealing and insulating can lights properly is a PIA. Even then, it's always a sticking point in the energy envelope of the home. It's best NOT to create a problem and then try to come up with a solution.

    Drilling numerous holes in my roof will create issues. So why am I drilling all these holes in my roof?

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