I’m in the midst of making a colubrid hatchling rack. It’s going to be PVC and hold 30 2.7qt tubs. I was originally planning on routing a small section in the back of each level for belly heat. But then I realized how incredibly tedious that was going to get. What’s everyone’s opinion on heating for a hatchling rack?
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I have both back heat and belly heat racks, and I prefer the back heat. The little channels for belly heat make it harder to get the tubs in and out.
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I’m just curious as well as I have no experience with back heat but would you say you still get a decent temperature gradient with that? Again please excuse my ignorance. I guess my concern was that it would radiate across more of the tube and not up like the other orientation? if that makes sense.
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It works both ways. It heats up the surface it’s attached to so it heats top and bottom either way. When you look at it with a thermal camera there isn’t much difference.
As @westridge pointed out, the tubs don’t get hung up on it. After 4-5 years of tubs sliding on top of it, some of them will crinkle and it jams the tub closed when it does. Jerking it loose is surely a rude experience to the resident lol.
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Your backround temperature is going to have a big effect on your gradient temperatures with either style tape as well.
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Jamming bit definitely make sense! I haven’t used self made racks for that long to have encountered those problems yet. @saleengrinch the problems I did encounter were what you had mentioned of ambient temperature, as my racks and a couple glass enclosures I keep in one half of my basement. Which doesn’t experience as much fluctuation, but a bit cooler and I battled heat loss depending on the design of rack, if it was open sided or not, or individual dividers. Why I curious if that orientation might help me with the way the heat radiated out of the front? Will be setting another one soon will have to experiment 
Oh and @ballornothing you have looked at it with Thermal camera, that’s awesome! And great to know you didn’t see much difference. Thanks for your feed back.
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I’m an insulation contractor, building science and thermal dynamics are the foundation of my trade.
You can’t be sure of the thermal gradient in a tub with just an IR temp gun. It only tells you surface temperature, not air temperature. It takes a thermal camera to actually see the gradient in a tub and even then it’s an imperfect solution. You have to manipulate the camera’s perspective but you can get a better idea than with a temp gun.
The air temperature of the ‘cool side’ of the tub is often a few degrees or more higher or lower than the surface temperature of your substrate. Basic thermal dynamics. Heat up air, you change the pressure. Air pressures flow, meet, and mix. With an IR gun all you can see is the surface temperature which may or may not be the same as the air temperature. There are a ton of variables that dictate it. If your room is too cold, it will ‘vacuum’ the warmer higher pressure air out of your tubs. If your rack heat is really high in a warm room it will create a sort of ‘positive pressure’ condition where tub doesn’t really exchange air with the outside creating that decreased gradient I mentioned by keeping the substrate in contact with warmer air, thereby warming the substrate.
Even then the surface temperature might be acceptable at times but due to the pressure condition the air temperature could be much higher while not causing a big effect on the surface temperature.
The thermal efficiency of your substrate also plays into this. Cypress absorbs heat slower than aspen, it’s more dense. Coco husk is a middle ground. Coco fiber and soil substrates vary based on density and air flow. If the bedding is extremely humid, it will absorb temperature at a different rate than when it’s dry.
They are an invaluable tool for the hobby but they aren’t fit for actually measuring the thermal gradient within a tub. Only a percentage of your snake is contact with the substrate.
Just to scare everyone a little more, houses work exactly as I described above but due the stack effect they flow air into your home from all of the worst places, like moldy crawl floors, basements, or from the attic or within the walls. Your entire house breathes all day. The indoor air quality because of that would really disturb you if you could measure it. If you have a forced air system for heating and cooling, it creates a whole other set of pressure conditions aside from the stack effect.
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This is sort of correct. If you heat up air the pressure will change but temperature and pressure are directly proportional. So if you heat up air the pressure will change it will rise. If you cool air the pressure will decrease.
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Correct. Your point is illustrated by the stack effect I mentioned multiple times. I apologize if my oversimplifying an explanation is a problem. It was already pretty verbose.
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