# led question



## kasilofhome (Feb 10, 2005)

QUOTE=painterswife;7538082]LED lights work better in the cold and save lots of electricity.[/QUOTE]

In my search for that info.. it seems from a non bias source you are right about them working better th a cf bulbs. 

I just want to know if the inch frost I find on unheated windshield in the winter which is why I am concerned ...it is a 3 d frost.. never saw frost like that till living here.

Will the heat produced deal with that.

We, in alaska are to be gifted with 17 million in led bulbs for are streets... 

Will it really work

Temps spend weeks at minus 30s in anchorage and maybe a week at a time at minus 40s

Fairbanks is much colder.


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## JeepHammer (May 12, 2015)

I'm not connecting the dots here...
Or something is wrong with the way my phone loaded the thread...

A little background on LEDs, and other common lights...

A 60 watt indancesant bulb draws (Obviously!) 60 watts,
60 watts devided by 110 volts = 0.54 Amps
This is just energy heating a wire to a bright glowing hot,
Most of the energy is wasted as heat.
Its a better heater than it is a light.

The same thing in CF will draw about 15 to 17 Watts, depending on the voltage inverter used, for same of argument, say 17 which is common.
17 watts devided by 110 volts equals 0.15 Amps.
By driving voltage up, with an inverter, the voltage can directly excite gass in the bulb that produce more light than heat.

The deal here is, the gasses condense below room temperature and get sluggish, and don't like to work when chilled, or frozen...
Great indoors, or above about 50F degrees, but not so good as temps drop.

LEDs don't rely on heat, they work at any temp pretty much.
Converting electrical current almost directly to light from materials in a 'Solid State'.
Since they are so very efficient at producing light, they produce very little heat..
My LEDs I use outside draw about 1.5 Watts,
1.5 Watts devided by 110 volts = 0.01 Amps.

They won't melt the frost off the mayonase jar I use to protect them.

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Not saying you CAN'T use LEDs, just not white light LEDs...
Infra-Red LEDs are used to heat things in industry.

Infra Red band width light strikes an object, and changes bandwidth, heating the object.
Curing chemical coatings is common, like paint.
Large powder coating places use Infra Red lights to cure the paint,
And layered coatings in electronics without overheating the electrical components around it.

The wave length of the LED is adjusted to react almost exclusively with what ever you are trying to heat...

Same idea with Passive Solar heating,
Sunlight will pass right through a clear window,
Strike an object in a room, change wavelength from the impact, and not be able to get back out through the window...
'Green House Effect'.

A metalized coating on a window can reflect the infra red spectrum,
And only non-heating 'White' light enters the room, so things DON'T heat up.


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## kasilofhome (Feb 10, 2005)

Thanks ..Im looking at if street lights and signal lights that use LED bulbs will provide the heat, as current bulbs are doing, to keep signal lights visible for practical purposes.

A few years ago there was a change in bulbs for a store sign and LED bulbs failed to be visible under the frost... if the state switches to led...it would be wise to have a heads up.


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## farmrbrown (Jun 25, 2012)

Yes, I see what you're asking now, and you were told correctly. They don't give off the same heat as an incandescent bulb. BUT if they were smart, they would run heat tape around the traffic lights and activate it during winter. The electric savings from the LED's should more than offset the extra juice for the heat.
Maybe talk to a local traffic engineer and give him the suggestion. If it works good he might get a feather in his cap and you might have a needed ally one day.
Who knows?


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## Harry Chickpea (Dec 19, 2008)

Unusual conditions. No, the LEDs alone likely wouldn't be up to that task. Traffic signals are hooded, which eliminates a lot of problems, and I'm sure that the designs will incorporate some sort of method to prevent the signals being obscured.

I always used starter fluid sprayed on the windshield and lit to remove excess frost. As long as you stop before the thin layer of meltwater is gone it is fine.


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## JeepHammer (May 12, 2015)

I can tell you from personal experence, since I do a lot of traveling, the LEDs in overhead traffic lights won't melt the snow off themselves.

A couple of years ago during a trip through Maryland & PA we stopped at every intersection because you couldn't see a single light unless you were right on top of it,
We nearly got hit dozens of time, finally pulled off until the sun did the work of clearing the lights.

In Wisconsin, they don't have nearly the problem,
And I'm wondering if the heat the signal light housing...
I can't be sure since I only see the lights from a dozen yards away,
But it looks like there might be a 'Clear' lense spaced out from the bulb.
Insulation maybe? A lense that reacts with bulb light to produce heat?
I don't know, didnt really think about it until now...

I believe I would contact the bulb manufacturers and ask questions,
Other towns/cities around you to find out what they are doing...


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