How can LEDs be used in sealed recessed-can lighting?

I'm looking at some of the Utilitech 13.5W model 0113539 recessed lighting Lowes has:
http://www.lowes.com/pd_113539-59179-DLS02-627D-WH-F1_0__?productId=4176973

How does that even work? There's a large heatsink on back, but it's supposed to retrofit into a recessed-lighting can.
Since those recessed cans were designed for incans, they're "airtight" for fireproofing and just not intermingling attic/joist air into the room.

I thought this was a mistake, that it must be meant to mount straight in a drywall ceiling instead, without a recessed steel-can housing. But it's got an E26 light bulb screw-base as a plug to go in there- that won't go accept an in-the-wall flex cable or anything in the ceiling, that's solely for going into a recessed can's socket.

Is it realistic to be able to keep these devices cool? This seems outright absurd. The heatsink can put it into the can, but then it'll just heat up the steel can.

Were any recessed cans made that were specifically suitable for LED cooling?

Anybody have experience with these Utilitechs? Some stuff I saw online said this model is bad for flickering esp when dimmed, but I wouldn't know without wiring it onto a dimmer.

The trim also acts as a heat sink.


If you think about it, it seems kinda bizarre to offer a bulb/trim combo instead of just a plain ol' bulb. But getting recessed bulbs cool enough turned out to be a daunting task (which eventually was solved by Philips, Lighting Science, and Feit). If you think about it, heat would naturally convect upward and get trapped in the can (at least for AT-rated fixtures). So, by connecting the trim to the bulb, you can use the trim as a heat sink. In addition, the manufacturers can now crow that installing their bulb (Utilitech you linked to, CREE CR6, various Sylavnias) also makes the fixture AT-rated (air tight, which refers to air entering the attic space through the fixture).


I've shied away from these for two reasons: (1) most of my recessed lighting is Lightolier, and those type of trim kits would requiring extensive jury-rigging to fit in my fixtures, and (2) I don't like the idea of eventually having mis-matched trims when the lights eventually burn out.


I've been using these:


http://www.homedepot.com/p/Philips-...lb-DISCONTINUED-420273/203273272#.UmFBmyiQ4wE


and these:


http://www.homedepot.com/p/Unbrande...-ECS-BR40-90WE-W27-120/203914616#.UmFBGiiQ4wE


...and both had no problem surviving a Virginia summer in my Halo H7ICAT with 30WAT air-tite trims (overkill on the air-tite) covered with 20 inches of insulation.

Having the LED emitter integrated with the trim makes for a much cleaner appearance than a separate trim+bulb. And for new construction it is marginally less expensive to use the integrated style.

Some of my CR6 retrofits are approaching three years old, and are extensively (4-8 hours/day) used. Have not had a single failure yet. In general, I switched a room at a time, so no concerns about mis-matched trim. I offered the incandescent BR30s on the local freecycle, and they were gone in a day!

The funny thing is, there's a pretty big finned heatsink (doesn't show up in the pic) in back that is wholly inside the sealed can. None of this heat conducts to the bezel.

Oznog said:

The funny thing is, there's a pretty big finned heatsink (doesn't show up in the pic) in back that is wholly inside the sealed can. None of this heat conducts to the bezel.

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Cargo-cult engineering?

Here is how you install a Cree version in cans that are NOT buried in insulation:
http://www.youtube.com/watch?v=2UKP_lvzY3A
The heat from the LED goes into the room through the trim heat sink. The heat from the electronics conducts through the can into the false ceiling.

If you have IC cans buried in insulation you may have to convert the recessed light into a flush mount where the heatsink is in the room.
Here is a video of the Glimpse by Lighting Science version:
http://www.youtube.com/watch?v=hKV0prWPIco

I thought LEDs ran alot cooler than an incandecent putting out the same ammount of light. Why is heat such a big deal here? Serious question.

Longevity.
If the product cooks itself to death before it pays for itself...

I just installed 8 Sylvania 6" Led Kits in the IC Lights in my parents kitchen. I left them on for over 8 hours to see how hot they got. They were barely warm to the touch. I would imagine the LEDs are not driven very hard. Since these IC Cans were rated for the insanely hot PAR38 incan bulb....I wouldn't worry about it at all bud.

dragonballz said:

I thought LEDs ran alot cooler than an incandecent putting out the same amount of light.

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That's true. The issue is that LEDs are less tolerant of high temps than incandescent lamps...

dragonballz said:

I thought LEDs ran alot cooler than an incandecent putting out the same ammount of light. Why is heat such a big deal here? Serious question.

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An incandescent bulb runs at 2700°K (2427°C). Many can tolerate 3000°K or even 3500°K. They may burn out a little faster. At the high temperatures the heat just leaves the bulb/can via radiation.

An LED usually runs at 85°C. It can tolerate a maximum of 120°C. The capacitor in the LED driver lasts 6,000 hours at 85°C or 50,000 hours at 60°C. So the components in the LED bulb can not tolerate much heat. (60°C vs 2427°C)
LED bulbs while cooler do produce heat. The best bulbs today produce light with 1/3 of the energy used, 2/3 is heat. So a 60 watt equivalent LED at 9 to 13.5 watts produce 6 to 10 watts of heat.
JTR1962 estimated an A19 size bulb in a ventilated space can handle about 4 watts of heat while keeping the capacitor at around 60°C.
To start off a simple A19 LED bulb can not maintain 60°C at the capacitor in free air let alone in a heat trapping IC can.
The bulb manufacturing get around this by making finned heatsinks to increase heat dissipation area. XLedia took this to the extreme by keeping the heat sink away from the tube with the electronics (So the heat only conducts to the surrounding air, not to the capacitor.). The manufacturing also make the bulbs bigger. Another trick is to coat/paint the bulbs to improve heat transfer by radiation.
They also let the whole bulb, not just the LED, run at 85°C. Now this results in a dead bulb in 6000 hours if the bulb is run continuously. So they advice people to run the bulbs 3 hours per day. If you use the bulb for <1 hour in the morning and <2 hours in the evening the capacitor may be in heat damaging hot state for only the 2nd hour in the evening. This let them raise total runtime by 3X or 4X to 20,000 to 25,000 hours.

Since a bright LED bulb (60W equivalent or brighter) is actually pushing the heat tolerance of the bulbs to the limit in a ventilated enclosure, installing one in a closed can will reduce the lifetime to unacceptable levels.
If you scroll up to my last post and watch the 1st video, notice Cree tell you to remove the plate at the top of the can to let the hot air into the false ceiling above the room. Can not do that with an IC can.
Now the trim plates of the fixtures specially designed to go into recessed cans are much bigger than an A19 bulb. So those run cooler as shown by bnemmie's post.

LEDninja said:

If you scroll up to my last post and watch the 1st video, notice Cree tell you to remove the plate at the top of the can to let the hot air into the false ceiling above the room. Can not do that with an IC can.
Now the trim plates of the fixtures specially designed to go into recessed cans are much bigger than an A19 bulb. So those run cooler as shown by bnemmie's post.

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The top plate has no insulation ability. It is attached to the vertically sliding L-bracket (which locates the socket vertically within the can) and helps to laterally stabilize the socket within the can. Both my non-IC rated Junos in the basement and my ICAT Halos in my family room have the top-plate/L-bracket setup, and both the bracket and the plate need to be discarded when installing the CR6s.

The only reason to remove the plate and bracket is to get more clearance (as they explain in your video at 1:45).

Hmm, Cree's "65W equivalent" only uses 10.5W because they've got a much better lumen/W figure.

The Utilitechs are I think 63 lumens/W, and 13.5W. The temp will be higher than the Cree due to wattage alone.

MattPete said:

The only reason to remove the plate and bracket is to get more clearance (as they explain in your video at 1:45).

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Removing the plate and bracket is to get more clearance is one reason. It is not the only reason.
Having air circulation in addition to conduction through the metal of the can helps cool things down.

In the video review of Cree's 9.5W A19 bulb the electronics area was measured at 85°C and up. The reviewer then showed the capacitors spec graph. At that temperature the capacitor will last just over 5,000 hours continuous running. At 60°C the capacitor will last 50,000 hours easy. This shows Cree has not optimized their bulb for the longest possible life (like Xledia is trying to do). I ended up buying the 6W. (9.5W > 3 watts light, 6.5W heat, 6W > 2 watts light, 4W heat, same size heat sink.)

In this case removing the plate allows the electronics to run cooler extending runtime. The Cree bulb/fixture will last a reasonable time if you do not remove the plate. But it will last longer if you do. And there is enough clearance in full size cans that you do not have to take the plate out, only in short cans do you need the clearance.
Marketing people do not always tell you everything.

Wow then a 13.5W light under the same design would get up to 110C... the caps aren't likely even rated for >105C. If your cap lifespan drops by 1/2 every +10C, that'd be less than 1000 hrs.

Oznog said:

Wow then a 13.5W light under the same design would get up to 110C... the caps aren't likely even rated for >105C. If your cap lifespan drops by 1/2 every +10C, that'd be less than 1000 hrs.

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Most of the heat from a Cree A19 bulb's LEDs goes down to a fairly small heat sink which surrounds the capacitor so the capacitor is almost at the same temperature as the LEDs. BTW Cree uses 105° caps.
Many other companies use different methods to get the heat out away from the capacitor.
- The Philips 'Alien Head' has 3 U shaped channels at the top sides of the bulb connected to the LED heat sink. These channels join together at a plate at the top of the bulb. A lot of the heat goes out and up away from the capacitor.
- Toshiba or Panasonic (can't remember which) has internal fins thermally connecting the plate the LEDs sits on to the glass globe. This moves heat to the glass a lot faster than the Cree bulb.
- Some GE and Sylvania use external fins surrounding the glass to increase heat sink area. The light emitting area is similar to a regular bulb but the total bulb size is closer to a B-I-G vanity globe.
- XLedia connects the LEDs to a heat sink that does not touch the tube with the capacitor. So the capacitor is at the temperature of the surrounding air, not the LEDs.

In your case the sheer size of the heat sink/trim plate will remove a lot of heat from the LED. The sheer size of the can will remove a lot of heat from the electronics/capacitor. If you can remove the top plate of the can as shown in the Cree video you get heat removal by convection in addition to conduction through the walls of the can.