light equal to 120W incan in ceiling can: heat issues w/ halogen, LED

My 1966 wiring isn't rated for halogens. I cannot buy the 120W incan spot/floods anymore, but the ceiling cans in my bathrooms are designed for that. So how can I get the amount of light needed without overheating the wiring or the can?

Worst case would be to get into the attica & replace the fixture. Maybe put an LED transformer up in the rafter so the heat dissipates into free air. Maybe I can wire all 3 lights into the same xfmr...

Or maybe an integral LED fixture rated for the heat of an LED xfmr within the box itself?

These are the large diameter lights -- 5 or 6" ???

Why not a LED reteofit bezel? Instead of LED "bulbs"?

bulb or bezel -- won't they produce the same amount of heat, since a given lumens needs to draw whatever amps & convert to DC to run the LED?

AFAIK the specs for an LED refer to the DC input to the LED, which is deceptive since the actual draw is AC to the transformer which creates the DC.

Do you understand the concept of lumens/Watt?

LED replacement lamps have about 5 times the efficiency of halogen, and therefore, for a given level of light provided, will consume about 1/5 of the electric power, and produce about 1/5 of the heat.

If I did my math correctly (which is always suspect), compared to a 120w BR40, a 16watt Hyperikon should put out 11.53 watts of waste heat, whereas the incandescent should put out 115 watts of waste heat.

Get an LED bulb, I think a 20W or 30W one is equivalent (in lumens) to a 120W incandescent.

At Home Depot, the LED with the highest wattage equivalent in BR40 size has 65watts.
The PAR38, outdoor, smaller diameter, goes to 120W. But only in that Home Depot chinese brand.
The PAR38 does not extend to the lip of the can, so it becomes a very narrow spot.

brickbat said:

Do you understand the concept of lumens/Watt?

LED replacement lamps have about 5 times the efficiency of halogen, and therefore, for a given level of light provided, will consume about 1/5 of the electric power, and produce about 1/5 of the heat.

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Do you understand that a transformer puts out a lot of waste heat? You have to add that to the waste heat from the LED itself.

lumen aeternum said:

Do you understand that a transformer puts out a lot of waste heat? You have to add that to the waste heat from the LED itself.

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DC to DC transformers are usually about 75 or 80% efficient, AC/DC transformers are usually 90%+

lumen aeternum said:

Do you understand that a transformer puts out a lot of waste heat? You have to add that to the waste heat from the LED itself.

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A lot? What do you mean by "a lot of waste heat"? Please educate us...

If by "transformer" you actually are referring to the LED driver circuitry built in to the base of a LED replacement lamp, then YES, it was fully accounted for in my statement about 5x the efficiency. If you are referring to something else, you need to explain...

Enderman said:

DC to DC transformers are usually about 75 or 80% efficient, AC/DC transformers are usually 90%+

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Most AC-DC drivers for LEDs are 83-88% with some lower and some higher. Most DC-DC where the input voltage is not 1.5V are over 90% and hitting 95 is very common.

ssanasisredna said:

Most AC-DC drivers for LEDs are 83-88% with some lower and some higher. Most DC-DC where the input voltage is not 1.5V are over 90% and hitting 95 is very common.

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I'm pretty sure pure sine wave ones are 90+

lumen aeternum said:

AFAIK the specs for an LED refer to the DC input to the LED....

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If you're talking about LED replacement lamps, that is incorrect. The published power draw is at the AC mains input.

We are talking LED drivers, and except for when you get into high powered units, it is rare for the driver to be pushing >90% efficiency. AC\DC transformers for 12V halogens and the like are hitting 90% when they are rated 40W+, 72W units over 90%

So? How is that relevant to the OP's question?

lumen aeternum said:

At Home Depot, the LED with the highest wattage equivalent in BR40 size has 65watts.....

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This Br40 (below) from Home Depot (made by Lighting Science) uses 18-watts, and puts out 1,260 lumens. That's roughly the same amount of lumens as the IR halogen 70 watt BR40 bulbs made by Phillips and Sylvania. It's also roughly the same amount of lumens as a 120watt regular-old incandescent:

http://www.homedepot.com/p/EcoSmart...le-LED-Light-Bulb-2-Pack-1003013102/206702061

Ignore the 90-watt equivalent rating (I've found those ratings all over the place) and focus on the lumens.

Compared to the 120watt incandescent, the led Br40 linked to above is 70 lumens per watt, vs. 10.5 low for the 120watt incandescent. With the theoretical max at 370 lpw, that means the led BR40 puts off 14.6 watts if waste heat (I think my logic is correct) vs. 116.6 for the 120 watt incandescent. So not only is the LED using a lot less electricity, it's giving off a lot less heat.

BTW: the 18watt rating for the LED bulb is for the entire bulb, led chips, built-in transformer, other electronics, everything.