Heating effects of different lightbulbs

In summary, the two light bulbs, an LED and a halogen with the same power consumption, will have different radiation spectra. However, if placed in identical closets with no heat escaping, they will eventually reach the same temperature T, but one may reach equilibrium faster due to differences in heat distribution. Unfortunately, the experiment may not run for a long time as the LED lamp will fail before the halogen lamp reaches its maximum temperature.
  • #1
f todd baker
61
22
Suppose I have two light bulbs, an LED and a halogen, but both have the same power P. Their radiation spectra are different, the LED radiating much less IR. Putting them in identical closets from which no heat may escape, will the walls and air in each come to some temperature T which, although increasing, will be the same for both?
 
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  • #2
f todd baker said:
Suppose I have two light bulbs, an LED and a halogen, but both have the same power P. Their radiation spectra are different, the LED radiating much less IR. Putting them in identical closets from which no heat may escape, will the walls and air in each come to some temperature T which, although increasing, will be the same for both?

What do you think?

First can I check what you mean by "power P" ?

Is it..

a) The same power going into each light?
b) The same amount of visible light emitted by each light?
 
  • #3
both consume and radiate the same power
what do I think? I think that there would be a time when both were at the same temperature ("equilibrium" between walls and air) and that temperature would be increasing. I think it possible that one would reach that equilibrium more quickly than the other.
 
  • #4
f todd baker said:
both consume and radiate the same power

That can't be true (in the visible, the question you were asked) given your previous statement.

f todd baker said:
Their radiation spectra are different, the LED radiating much less IR.
 
  • #5
I do not understand that. A bulb which is rated at 13 W, e.g. means that perhaps 8 W is radiated as visible light, 5 W as heat (IR). Whatever, whatever the bulb consumes must equal the energy radiated or else energy will be being stored somehow in the bulb.
 
  • #6
F Todd: You are correct. Conservation of energy means all bulbs consume as much as they emit overall. That's why in b) I asked if you meant equal _visible_ output. (A 500 lumen halogen consumes more power than a 500 Lumen LED).

If the input power is the same then I would expect both boxes to behave more or less identically. However there might be minor differences. For example a halogen will be hotter than an LED so more of the power will leave the bulb by conduction/convection rather than radiation - so the temperature gradient between bulb and outside will be different (I think).
 
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  • #7
Sadly, the experiment will not run for very long as the LED lamp will overheat and fail long before the halogen lamp maxes out...
 

1. What is the difference between incandescent and LED lightbulbs in terms of heating effects?

Incandescent lightbulbs produce heat as a byproduct of light generation, while LED lightbulbs do not. This is because incandescent bulbs use a filament that heats up to produce light, while LEDs use semiconductors that convert electricity directly into light, resulting in little to no heat generated.

2. Can the heat generated by lightbulbs impact the temperature of a room?

Yes, the heat generated by lightbulbs can contribute to the overall temperature of a room, especially if multiple bulbs are being used. Incandescent bulbs produce more heat than LED bulbs, so they may contribute more to the room's temperature.

3. Are there any safety concerns related to the heating effects of lightbulbs?

Yes, incandescent bulbs can get very hot and potentially cause burns if touched. Additionally, if an incandescent bulb is used in a lamp or light fixture with a wattage that exceeds the maximum recommended, it can cause the fixture to overheat and potentially start a fire.

4. Do different types of lightbulbs produce different levels of heat?

Yes, LED bulbs produce significantly less heat than incandescent bulbs. However, there are also variations within LED bulbs themselves, such as the difference between warm and cool white LEDs. Warm white LEDs tend to produce slightly more heat than cool white LEDs.

5. How can I minimize the heating effects of lightbulbs in my home?

To minimize the heating effects of lightbulbs, you can switch to energy-efficient LED bulbs, which produce less heat. You can also opt for lower wattage bulbs or use natural lighting when possible. Additionally, keeping your light fixtures and lamps clean and dust-free can help prevent them from overheating.

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