Halogen vs incandescent for heat

[Joma]

Bought a flood for heat at my local hardware store. It’s a 75w halogen flood. It’s temps are working well. But I wondered about halogen VS incandescent. Anything I should know? @Tom I think you may be able to help. Thx

An aside. For those that may remember I use the sun in the window for heat. I needed to swap this up for spring/summer as the sun’s angle in the window at this time of year does not provide adequate heat and does provide enough solar power to run higher watt bulbs. It’s a constant adjustment I’m finding.

 

[Tom]

@Markw84 is much more knowledgable about lighting details than I am. I believe he said that halogen bulbs are more desiccating than standard incandescent bulbs. Hopefully he will chime in and correct me if I'm wrong.

 

[Joma]

@Markw84 is much more knowledgable about lighting details than I am. I believe he said that halogen bulbs are more desiccating than standard incandescent bulbs. Hopefully he will chime in and correct me if I'm wrong.

Thx Tom. I will wait for more info. I hope not because it seems like incandescent anything is hard to find these days.

I’m working on his outdoor enclosure so that will help mitigate too.

 

[Markw84]

Halogen bulbs operate at a much higher temperature than a regular incandescent. The higher the temperature of the source, the more and shorter wave IR is produced. So the spectral curve of the halogen bulb shows very high amounts of very near-IR. I feel the near IR (IR-A) is the most desiccating and potentially most dangerous. Although SOME IR-A is beneficial, it is very easy to overdo it in our small enclosures using artificial light sources as our heat.

I look at sauna manufacturers and their extensive history with best and safest heat in a closed system, and we see that they all have found the longer wavelenght IR is the deeper heating and more gentle and less damaging. The best saunas use IR-C as their heat source and have found IR-A is too damaging and harsh.

If you look at the spectral curve of a halogen bulb you see the vast amount of energy produced is far more IR-A than even Light. Also, the IR produced is ALL IR-A, and the very short wavelength IR from 750nm - 900nm for the bulb of it. It has a very sharp peak and decline and is mostly very near-IR. Compared to natural sunlight, the peak of the curve for natural sunlight is in the middle of the visible spectrum, around 500nm. There is far more energy in light than there is in IR. Since the brightness of light is a key stimulus to basking activity, think of how much near-IR a tortoise is baking in with the same intensity of light, under a halogen vs natural sunlight. It is at least 10x more near-IR.

Halogen is actually a type of incandescent, and indeed our regular incandescent also have similar near-IR curves, although flatter and distributed further into a bit longer wavelength IR. So it is less harsh, and more importantly, we mitigate this by using low wattage basking bulbs AND - I alway use a bight LED light source near the low wattage incandescent - so I am creating a much brighter light source with a much, much reduced IR component.

 

[Joma]

Halogen bulbs operate at a much higher temperature than a regular incandescent. The higher the temperature of the source, the more and shorter wave IR is produced. So the spectral curve of the halogen bulb shows very high amounts of very near-IR. I feel the near IR (IR-A) is the most desiccating and potentially most dangerous. Although SOME IR-A is beneficial, it is very easy to overdo it in our small enclosures using artificial light sources as our heat.

I look at sauna manufacturers and their extensive history with best and safest heat in a closed system, and we see that they all have found the longer wavelenght IR is the deeper heating and more gentle and less damaging. The best saunas use IR-C as their heat source and have found IR-A is too damaging and harsh.

If you look at the spectral curve of a halogen bulb you see the vast amount of energy produced is far more IR-A than even Light. Also, the IR produced is ALL IR-A, and the very short wavelength IR from 750nm - 900nm for the bulb of it. It has a very sharp peak and decline and is mostly very near-IR. Compared to natural sunlight, the peak of the curve for natural sunlight is in the middle of the visible spectrum, around 500nm. There is far more energy in light than there is in IR. Since the brightness of light is a key stimulus to basking activity, think of how much near-IR a tortoise is baking in with the same intensity of light, under a halogen vs natural sunlight. It is at least 10x more near-IR.

Halogen is actually a type of incandescent, and indeed our regular incandescent also have similar near-IR curves, although flatter and distributed further into a bit longer wavelength IR. So it is less harsh, and more importantly, we mitigate this by using low wattage basking bulbs AND - I alway use a bight LED light source near the low wattage incandescent - so I am creating a much brighter light source with a much, much reduced IR component.

View attachment 271801

View attachment 271802

Thank you. Couple more questions.

1) what wattage incandescent do you use?

2) is it a flood?

3) would you recommend using it in a reflective dome or not (ie does that intensify the IR too much)

 

[Markw84]

Thank you. Couple more questions.

1) what wattage incandescent do you use?

2) is it a flood?

3) would you recommend using it in a reflective dome or not (ie does that intensify the IR too much)

I personally use 65 watt and definitely flood (BR) type bulbs, not spot (PAR). Those are simply easy for me to find in bulk. A lower wattage would be fine - your thermometer and height you wish to mount is your guide. The same would be true of whether or not to use a reflective dome. I do, as I like the area it creates for a basking zone, and that it shields my eyes from the light while viewing the tortoises. My belief is that the lower wattage, combined with the brightness of the LEDs creates the zone I want with birght light and more acceptable level of IR. Not the IR totally outweighing the light. Where you are and in your application, I would think the very efficient and low wattage LEDs would be a great advantage.

 

[Joma]

I personally use 65 watt and definitely flood (BR) type bulbs, not spot (PAR). Those are simply easy for me to find in bulk. A lower wattage would be fine - your thermometer and height you wish to mount is your guide. The same would be true of whether or not to use a reflective dome. I do, as I like the area it creates for a basking zone, and that it shields my eyes from the light while viewing the tortoises. My belief is that the lower wattage, combined with the brightness of the LEDs creates the zone I want with birght light and more acceptable level of IR. Not the IR totally outweighing the light. Where you are and in your application, I would think the very efficient and low wattage LEDs would be a great advantage.

I just got a 65w incandescent flood. I will switch out my halogen and figure out the new height. Hoping to get him outside part time soon as well.

During the times of year the sun comes more directly into his enclosure and he has to be inside - usually between about September and March - I simply use the sun from the windows for heat. It works very efficiently and avoids the problem of burning, drying and uneven heat distribution.

Thank you again. Jo