Helpful? 0

“Air-sealed” can light retrofit vs. Tenmat cover in attic?

I’m planning some air sealing work in my attic. I’ve got a bunch of recessed can lights to deal with, and I had been planning to use Tenmat rock wool light covers on the attic side. This would involve caulking (say, Tremco acoustical sealant) or foaming to seal the Tenmat cover, plus taping up any cuts to allow for electrical wires, etc. After first going into attic, pulling back existing insulation, sweeping the area clean, etc.

Now I’ve seen some LED retrofit lights that are supposed to be air-sealed, e.g., Nicor’s Maxcor DLR56. It has a solid face and a gasket on the back side of the flange. It’s basically a plug-n-play replacement for the current can light, except that it’s a) LED, b) air-sealed (?), c) white, instead of the yellowed plastic of original build. I can probably replace these in a minute, from the relative comfort of my living room, instead of working in the attic.

So, can these retrofit LED recessed down lights (90+ CRI, Cree LEDs, etc) actually eliminate the need for the attic light covers? Am I duplicating efforts to do both?

Thanks for your thoughts.

P.S. I’ve tried to go for higher temperature lights (e.g., 5000K vs. 2700K color), on the theory that anything approaching natural sunlight is better. Alas, I appear to be conditioned to prefer soft white that approximates incandescent. In your experience, is there a big difference between 2700 and 3000? Which would “old folks” likely prefer?

Asked by andrew c
Posted Sun, 06/22/2014 - 09:18
Edited Mon, 06/23/2014 - 04:30


5 Answers

Select your preferred way to display the comments and click "Save settings" to activate your changes.
Helpful? 0

P.S. The can lights are going to be replaced anyway, partly for cosmetic reasons. The real question is whether or not this eliminates (largely?) the need for air sealing from the top side.


Answered by andrew c
Posted Sun, 06/22/2014 - 09:31

Helpful? 0

I haven't use the Tenmat covers but if they're made of rock wool, how air-tight can they really be? My guess is that they're fire-resistant, have some insulating value, easy to install, and leak somewhat.

I have used LED retrofit modules on several occasions now, and as far as I'm concerned, they perform really well. Color temperature in the 3000k-or-less range is much more likely to please most folks in their homes, higher temps may be appropriate at work or in commercial spaces.

What you might do is install some of the LED modules and then use a blower door to see how they perform. If the drywall is flat and the gaskets seat tightly, you may not need to do much from above.

FWIW, there are other types of can light covers on the market. I saw some recently that were basically cardboard boxes. And, it is always possible to make your own out of plywood, drywall, rigid foam, etc.

Answered by David Meiland
Posted Sun, 06/22/2014 - 13:06

Helpful? 0

On your last question regarding LED color temperature: 2700 and no other!
I'm young enough to be enthusiastic about LEDs but old enough that I can't stand anything that doesn't mimic incandescent. (Needless to say, CFLs never entered my living space.) I've just completed a new house in 100% LED, and couldn't be happier. I think when fully blazing, I'm consuming about 300 watts. I found that the difference between 3000K and 2700K is not subtle, it is gaping. The warmer (2700K) is a very accurate copy of incandescent,, whereas even 3000K looks blue and makes everything feel like a threadbare Kmart aisle. Your impressions may vary; different brands may vary, but I scour the Big Box shelves looking for 2700, which is usually a tiny fraction of their stock.

Answered by Andy Chappell-Dick
Posted Sun, 06/22/2014 - 18:11

Helpful? 0

In my opinion, you should never install recessed can lights in an insulated ceiling. If you are going to the trouble of replacing the fixtures, you should replace them with surface-mounted fixtures (for example, track lights or pendants). Even the best recessed can light will leak air and will displace insulation, creating a hot spot in your ceiling.

I suggest that you read this article: Recessed Can Lights. The article notes that not all recessed can lights can be safely capped on the attic side.

If your fixtures are IC-rated, it is safe to install a cap like the Tenmat cap. If they are older fixtures that are not IC-rated, they lack a thermal switch, and therefore can't be capped.

Anyway, if you are pulling the fixtures, I strongly suggest that you choose to go with surface-mounted fixtures.

Answered by Martin Holladay, GBA Advisor
Posted Mon, 06/23/2014 - 05:01

Helpful? 0

Thanks to all for the useful feedback.

Martin: I’ve read all the warnings about recessed can lights, and agree that they should be avoided. I’d never accept them in a new house design. At this point, the budget probably can’t accommodate complete replacement with surface mounts (I’ve got 14 of the blasted can lights!) Since the cans are IC rated, I’m leaning toward keeping them.

I also face another common problem: we have a history of moving frequently. We’ve rarely been in one city for more than five years. (It’s jobs, not necessarily relations with the neighbors ;) ) I see opportunities to make houses more comfortable and more energy efficient, but it’s hard to make those improvements pay off, as most buyers won’t pay for them when they can’t see them. I’m willing to lose some money for increased comfort, but there’s a limit.

Again, thanks for the feedback; I value the information and advice at this website.

Answered by andrew c
Posted Mon, 06/23/2014 - 07:49

Other Questions in Energy efficiency and durability

The differences between mass and insulation

In Green products and materials | Asked by Nathaniel G | Sep 15, 14

Where Did Vestibules Go?

In General questions | Asked by Malcolm Taylor | Sep 18, 14

Air and moisture proofing.

In Energy efficiency and durability | Asked by Dave B | Sep 18, 14

Thoughts on Insulating Renovation

In Energy efficiency and durability | Asked by Dave Bentley | Sep 18, 14

Conditioning and venting a small cellar - Western NY

In General questions | Asked by flitch plate | Sep 17, 14
Register for a free account and join the conversation

Get a free account and join the conversation!
Become a GBA PRO!