Efficiencies? Where does the power go that is not turned into light?

Okay, I'll kill the suspense - heat!

All electric heaters operate at the same level of efficiency. That is, they are all 100% efficient. You could use a toaster from 1940 or one of those new fangled oil filled electric heaters and they both produce the exact same amount of heat per unit power applied.

Doing the math, if you apply 1 Watt of electricity you get 1 Watt of heat!

"I've been wondering for some time now if infrared LEDs could be used as heaters for small rooms or vehicles... "

Just right for rooms in a small doll house and/or matching scale auto.

You can look up the voltage and current specs from various manufacturers via Google.

Don't be so creative there Mr. Stan, have you not seen the fancy "heat sinks" needed to cool these new high power LED'S? I can only imagine how hot the new auto headlight LED'S are..

Maybe this infrared LED heater needs to be invented by me... hehe

Donald

You'll have to "read between the lines" of the post by Anon. Hero. Well, maybe not quite between the lines. With the current, state-of-the-art technology regarding infrared LEDs, you're barking up the wrong tree. Do the math to find out how many LEDs you'll need to generate a few BTUs

I just reread it. The poster was speculating that you might use IR diodes as a heat source and that it might be more efficient.

My point was that regardless of the method, they are all 100% efficient. LEDs will generate less heat and more light than say Halogen lamps for equal input of power at the same spectrum of visible light, but in this case the desired output is heat, so LED IR lamps have no advantage over a standard IR lamp or even a toaster if you don't overload the elements to the point where they emit visible light.

Anon., Sorry if I was a bit confusing in my post. I was trying to explain that you had given him the right answer even if it was a bit vague and if he would do simple math as Bill did in post #9, he would see the impracticality of using LEDs to produce heat given the current state-of-the-art.

Ah, I am the one who is sorry. I should have read your post twice! ;-)

Yes, I did the math right after posting, thousands are required, so not so good an idea as I thought.

Hang in there! One day it might be a great idea. Cheers!

You should not confused light with heat, they're different concept. The heating power of the led is much smaller than a common incandescent lamp. I think you would need a large array for producing a few Watts. Honestly, I have ever heard before of such an application for heat generation... but we can try to find a forerunner

Infrared LED wavelength is about 1300-1500 nanometers (near infrared). Heat is in the range of about 10000 nanometers and longer (far infrared). There are no LEDs available in this range.

It is not a problem converting electricity efficiently to heat.

We waste a lot of heat making electricity, if you want heat burn something.

In a vehicle we waste a lot of heat making it move, taking the waste heat from the cooling water is fine. The alternative would be to take electricity from the alternator and turn it into heat. Humans produce waste heat, if you are driving one of these new fangled electric vehicles with no combustion engine, why not wear some wool clothes, trap some and keep yourself warm. This seems like a solution to a problem that doesn't exist.

Sure! LED's, whether infrared or not, consume approximately 50 mW of power. If you need 500 W to heat something, then you'll need about 10,000 LED's.

I think it best to acquiesce to #4, Campbell Lighting. He (they) might know something we don't.

cr3

Watts are watts are watts. V*I in over time gives the heat. However, I think where the poster is going with this, is that we want to use IR to make us feel warm due to the radiation as opposed to a convection heater that heats the air and then transfers the heat in the air to the objects in the room. Of course radiant heat heats the objects in the room that then transfer their heat to the air through convection. A radiant heater in a cold garage warming my body (on one side) is a lot more efficient than heating all the air in the garage just so I can change my oil in the dead of winter.

LEDs as a heater? , i will take that project , I &you could use simple diode for that

for vehicles , shut of air conditioning

small rooms ? how small

coil heaters are almost 100% efficient

are you trying to contribute to global warming

Even if IR LEDS gave off IR in the heat band, (only near) you would need thousands of them to warm up a room as their powers are very small.....

If you want to heat with electricity, then use a resistive heater as someone else mentioned, even if it came from 1940! Their post was fully correct!!

It is better to not heat with electricity. If possible, gas, oil wood are cheaper, pellets is bes or wood!! Renewable CO2.....

Who said LED's MUST be small?

I didn't recall reading the size of the LED's as a constant, anywhere in the world.

LED's can be very large and extremely powerful. They just don't last as long as the duration of the crystal is greatly degraded via increased voltages.

Yes, you can burn them very bright and extremely hot. Ask Bryan Warner from Electroled, the world's largest manufacturer of LED's. (Great guy).

He's manufacturing over 500,000 per month, last I asked. (Probably more by now...)

They just won't do it for very long, under high voltage. So, efficiency, can be gaged by the time of the energy needed to heat the area and the power consumption for the duration of the burn, vs. the life of the crystal, at maximum voltage.

They'll burn very bright, for a few seconds... what more can we ask of them? (or anyone, for that matter).

What you'll need, number four, is the self refrigerating aluminum can, for an enclosure and advanced nano-crystal formations which can handle super high voltages. You might try transparent aluminum silica dioxide crystal growth, under high pressure environments. (Might be cheaper just to use synthetic diamonds, really big ones).