IR-LED as heat source


I was searching for an alternative heat-source from common IR-bulbs, and IR-Leds came to my mind. So I was searching and all I could find were threads at least 5 years old saying it was impossible due to the poor performance of IR-LEDs. But today there are cheap IR-LEDs that would put out ~700mW of 950nm IR-light. Now are these LEDs suitable as a decent heat-source?

Best regards, Jazzar

P.s. I'm also aware there are different types of heat sources and what not but I'm only interested if this is achievable with LEDs ;)

You could probably get more heat out of a cheapo resistor...


Yeah you will get naff all heat from it. It is not that wavelength of IR.

What are you wanting to heat up/keep warm?


A small fornicarium(ant-colony in a box) is my target. And LEDs mounted above would look incredibly nice :-)

Point is I only need the heat energy a 10W bulb would produce, so are there any small (IR)lamps in the lower voltage area? I know of those pilot lamps wich would also look quite nice.. A key feature would be the directional heat radiation.

Greetings, Jazzar

Sorry to smile but this is as good as it gets in the Freudian Slip department.




And I thought I was the only one who noticed. I literally laughed out loud.



Ok now I’m lost guys, what did I write thats so funny?

You meant formicarium.

Fornication is something quite different ;)


;D ;D ;D


Indeed forMicarium^^

Infrared lighting a Fornicarium? Sounds like hidden-camera porn to me..

Only a small one :wink:

Now… Anyone any suggestion for heat from the Low-voltage area? I read something about Thermofoil, but I couldn’t find any distributer…

heat from the Low-voltage area?

The problem with this is that you still have to supply the power so as the volts drop the current required increases. So at 5V you have to supply 2A to get 10W. As mentioned LEDs are not long enough wavelength for heat and you would still have to supply 10W to get 10W heat. Your best bet is a resistor.

Your best bet is a resistor.

What about peltier plates perhaps?

Not as efficient as a resistor because you loose energy doing the heat transfer from one side of the plate to the other. Great if you want to cool but inefficient if you want to heat.

I agree with Grumpy Mike . . . a resistor is the right way to go.

I have previously used a resistor and an old wall wart power supply to create a small heater for a scientific test instrument. It is relatively simple to calculate the correct size of resistor based on your target wattage and wall wart capacity.

Add a properly sized rheostat if you want to be able to vary the heat slightly . . . or go all out and create an Arduino based thermostat to accurately control the heat for your ant farm

Maybe a xenon lamp would do the trick when painted black, from my calculation they consume about 8Watt and are made to last at their maximum temperature. Now combined with a Mosfet, an Arduino and a NTC/PTC should work well as regulated heat-source. With a Socket they schould also be easier to exchange.


a xenon lamp would do the trick when painted black, from my calculation they consume about 8Watt and are made to last at their maximum temperature.

But are they when they are painted black. The paint will act as an insulator and allow the heat to build up internally in the lamp, thus pushing it beyond the limit of what it was designed for.

Am I missing something here, a resistor is the simplest possible component and the cheapest and most reliable so what is the problem?

Ok point taken, I thought a lamp might've been easier. But then how do I calculate the Resistor?

May I say:

U = R * I and
E = U * I thus:

U² / E = R

U = 5V
E = 10W

hence: R = 2.5Ohm
and:  I = 2A



It's pretty easy and efficient to make heat from electricity. As others have said a 20w wirewound resistor would be a good bet. I have personally found that LM298s make piles of heat. You do want to make sure you're using unregulated current to make your heat, otherwise 25% or more of your heat is going to be coming out of your regulator, rather than where you want it to go.