Efficiency/heat generation of Incandescent vs Halogen

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Paul1977

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#220207 31-Jul-2017 15:21

Purely academic question that I'm trying to get to the bottom of just for my own interest:

Halogen bulbs are apparently more energy efficient than incandescent bulbs, but they apparently also run hotter. How can this be the case?

If they are more energy efficient then that means that more of the energy is going into generating light, the counter of that surely being that they generate LESS heat?

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timmmay

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#1834396 31-Jul-2017 15:34

They may put out more light per watt consumed, but I don't think they can put out more light and heat. All electrical power turns into heat when used in this way at 100% efficiency. The only question is distribution.

wellygary

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#1834405 31-Jul-2017 16:10

In totality the "heat" output should be lower - more Watts are being transformed into visible light, thus there is less energy radiated as IR ( or heat)

BUT,

The lower overall heat might be more concentrated in certain parts of the lamp resulting in the maximum temperature of certain components fof the Halogen bulb being higher than the maximum temperature of the incandescent bulb- which may be radiating its IR through a larger surface area, thus having a lower maximum "temperature"..

Paul1977

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#1834408 31-Jul-2017 16:11

@wellygary:

In totality the "heat" output should be lower - more Watts are being transformed into visible light, thus there is less energy radiated as IR ( or heat)

BUT,

The lower overall heat might be more concentrated in certain parts of the lamp resulting in the maximum temperature of certain components fof the Halogen bulb being higher than the maximum temperature of the incandescent bulb- which may be radiating its IR through a larger surface area, thus having a lower maximum "temperature"..

Right, that makes sense. Thanks.

richms

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#1834485 31-Jul-2017 18:28

halogen capsules are a lot smaller than the envelope of an incandesent lamp, so the glass will be much hotter. If you have the halogen inside a normal shaped incandesent lamps, they will be marginally cooler but not a whole lot in it.

Richard rich.ms