Turn your CHE into a RHP

Before i get into the actual build I wanted to show how the CHE can be regulated to a safe temperature. An unregulated CHE can run in excess of 450+ degrees f. This is way to hot to be used safely with a snake, but there is a way you can make it work inside and outside of an enclosure.
This is a picture of my 80w RHP running on full power. I use it with an on/off thermostat in my 4x2ft custom enclosure.
http://i1172.photobucket.com/albums/...psgx3au92a.jpg
As you can see at the hottest part its running about 180 degrees f. Quite warm but not burning to the touch as you can hold your hand on it.
This is the CHE i use in my following design.
http://i1172.photobucket.com/albums/...pspfkx1gdi.jpg
Once again you can see it is operating at a temperature of about 180 f. The same as the RHP pictured above.

MATERIALS:
http://i1172.photobucket.com/albums/...psv76voare.jpg

You will need

100w Ceramic heat emitter

Light fixture

3 feet of picture hanging wire, the more malleable the better

A piece of aluminium screening roughly 14 inches in diameter

A drill with metal bit

Wire cutters or tin snips

An infrared temperature gun

A lamp dimmer

A thermostat ( i used an on/ off zilla temperature controller)


The length of wire and diameter of screen will depend on the size light fixture you buy. I used an 11 in. diameter light but you could also get a 9 in or whatever else you happen to have.

1. Screw 100w heat emitter into fixture

2. Cut your aluminium screen to match the size of the light plus a little extra.
http://i1172.photobucket.com/albums/...psiewcfbhc.jpg

3. Cut your length of wire i would start with 3 1/2 ft and trim as needed.
http://i1172.photobucket.com/albums/...psnntrosdx.jpg

4. Drill holes along the bottom of the side of the heat fixture
http://i1172.photobucket.com/albums/...psdrfzm1fx.jpg

5. Fold the top part of the screen down and weave the picture wire through the holes you drilled and through the folded over screen.
http://i1172.photobucket.com/albums/...psshq7rlat.jpg

6. Once you have woven the length of the wire through all the holes twist the two ends together and shove them through a hole. You may need pliers to push the twisted wire through.

This is what the bottom looks like completed.
http://i1172.photobucket.com/albums/...psoqlbauc3.jpg

This is the wiring setup. I plugged the light fixture into the lamp dimmer set on the lowest setting and then plugged the lamp dimmer into the thermostat.
http://i1172.photobucket.com/albums/...psfnqxv5ye.jpg

This is the finish product running at around 170f.
http://i1172.photobucket.com/albums/...psbx2yoapi.jpg

You can also use this combination on top of a screen lid as well you just need the lamp dimmer and the thermostat.

Happy DIYing

I would never place a fixture like that inside a cage. Snakes have a long history of climbing on to and even inside these and coiling around them. I wouldn't want my snake to coil around such a thing.

I also do not see what problem you are solving.

Ive used CHEs a lot. Im currently using one for my new ETB. Im using it in the wire CHE fixture with the tstat probe secured to the rim of the fixture. This is of course outside the tub and working great. However, to give the hotspot I want the CHE is reading well over 500F when it is kicking out at 100%. I don't see the issue with something reaching such a high temp if the snake has no way to get to it. If I restricted the CHE to stay at a safe temp to touch it would never create the desired hotspot.

What is this project for? Maybe Im missing something.


Im also concerned with the distance between wire holes. I fear a determined snake would be able to get under and then inside the screen you added. That is if you are in fact placing this inside a cage.

The outside of the lamp fixture reads 88 f. So if the snake did decide to "coil around it" it would actually be at the appropriate temperature for prolonged contact. When operating a heat source at a max temperature of 180 f you run significantly less risk than as you said running at 500f.
As to the problem im solving its people who use ches and set them on top or inside of an enclosure running at full power. Which people do at risk to their animals. This is a much safer alternative when placed on top of a cage as it wont burn the snake.
If you place your holes close enough and you have wire thats easily malleable ( combined with the fact that the light would be hanging several feet off the floor makes it hard for me to see that happening . But you have to watch and monitor as will all things.
No one is telling you to use this. Or what to do with it. Its a DIY forum where people post things they made. Where other people can use all part or none of the idea.
Instead of trying to bring other peoples ideas down you should figure out a better one.

Quote:

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Originally Posted by Alexio

The outside of the lamp fixture reads 88 f. So if the snake did decide to "coil around it" it would actually be at the appropriate temperature for prolonged contact. When operating a heat source at a max temperature of 180 f you run significantly less risk than as you said running at 500f.
As to the problem im solving its people who use ches and set them on top or inside of an enclosure running at full power. Which people do at risk to their animals. This is a much safer alternative when placed on top of a cage as it wont burn the snake.
If you place your holes close enough and you have wire thats easily malleable ( combined with the fact that the light would be hanging several feet off the floor makes it hard for me to see that happening . But you have to watch and monitor as will all things.
No one is telling you to use this. Or what to do with it. Its a DIY forum where people post things they made. Where other people can use all part or none of the idea.
Instead of trying to bring other peoples ideas down you should figure out a better one.

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Im not trying to bring you down. Im trying to understand the purpose of the build. I just don't understand what we are fixing here. Im also trying to make sure you are doing this having thought about all possible issues. Im seriously just trying to help.

Any CHE, bulb, other heat source should be controlled. Be that with a tstat, dimmer, or distance. They should ALL be monitored and controlled. No matter if they are inside or outside.

Now what I don't understand is how the setup you created is going to provide a proper hotspot once it is set up over a cage. At only 180 the fixture is going to need to be really close to the surface it is trying to heat. If a CHE is properly placed outside of a cage and needs to run with a center temp of 500+ to create the correct hotspot on the surface of the hotspot that is just what it needs to do. It is no danger to anything when done correctly. I can assure you that regulating my CHE to a safe to touch temp will never give me what I need to heat my ETB.

I'm gonna sort of piggy back on KMG's comments. First of all, i dont want to knock your DIY spirit, but i think the problem is that even thought RHP's and CHE's both use IR to heat the cage, they work in different ways (wow, that was a lot of acronyms!) Full disclosure: I do not know how RHP achieve their heating results with such low surface temps, and i surpassed my 5 minute google limit researching (its a forum post, not a term paper, right?) But basically, and i think this is what KMG is getting at, just because a RHP heats effectively with a low surface temp doesn't mean a CHE will also heat effectively with the same low temp.

Or maybe that is not what you are getting at at all. :confusd:

Again, I'm really not trying to dump on your idea, please tell me if there is something that i am misinterpreting here.

What wattage is that CHE? My 150 watt ones gets the dome housing to 107F even lamp dimmered down to 1/4 power. I don't see how yours is only getting 88F on the dome housing. Like mentioned, I would never put a CHE and housing inside a cage. Just asking for trouble. If it works for you, more power to you but me, no way.

Quote:

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Originally Posted by dkatz4

I'm gonna sort of piggy back on KMG's comments. First of all, i dont want to knock your DIY spirit, but i think the problem is that even thought RHP's and CHE's both use IR to heat the cage, they work in different ways (wow, that was a lot of acronyms!) Full disclosure: I do not know how RHP achieve their heating results with such low surface temps, and i surpassed my 5 minute google limit researching (its a forum post, not a term paper, right?) But basically, and i think this is what KMG is getting at, just because a RHP heats effectively with a low surface temp doesn't mean a CHE will also heat effectively with the same low temp.

Or maybe that is not what you are getting at at all. :confusd:

Again, I'm really not trying to dump on your idea, please tell me if there is something that i am misinterpreting here.

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Actually, RHP's and CHE's both heat the same way. Except an RHP spreads the heat over a much larger area, and a CHE concentrates it. Either way, it's a heat coil (essentially a big resistor) that heats up; it's just a question of how much and how spread out it is. If you compare a 100w CHE with a 100w RHP, they both make about the same amount of *total* heat. If you dim the CHE until it is the same temperature on the surface as the RHP, it's only putting out a fraction of the heat because it is so small. Picking numbers for convenience, let's say you had a RHP that was about 10" x 10" (100 square inches) and 100 watts, and a CHE that is also 100w and has a surface area of around 10 square inches. If you run that CHE at 10% power, it would heat up to roughly the same surface temperature (all else being equal) as the RHP. But it's putting out a lot less total heat because it's smaller. If you set ten of them next to each other, all running at 10% power, you'd essentially end up with the same thing as one 100w RHP.
But basically, a 100w CHE running at 10% power is a 10w RHP. If your enclosure requires 100 watts' worth of heat, 10 watts isn't going to do it.

Incidentally, a UTH (or heat tape) is basically exactly the same thing but even more spread out and made to be very thin so it can fit under things. A ~20w UTH has a similar surface (actually smaller probably, but I'm rounding off to easy numbers again) area to a RHP in the ~80 watt range. In other words, power that 80w RHP down to 25% and it's basically an absurdly fat UTH. The reason a UTH does not heat the air well and also has a real possibility of overheating is that in normal usage it is insulated from below by whatever the enclosure is sitting on, and from above by the substrate. Insulation means that heat that's being produced does not escape; so the temperature can climb even with relatively little power input.

What it boils down to is that all of these heating devices basically work by making coils inside them get hot. The difference is just a question of how much surface area the wattage is spread over.