Temps in my rack are off

As the title says the temps in my (homemade) rack are a bit off and it bothers me a little. It's a BP rack built of plywood and it's 12 levels high.

This is what I use:

CB70 tubs from Visionproducts.
A Habistat thermostat.
Habistat Vivarium heat mats.

The thermostat probe is placed on the third level counting from the bottom, it was placed on the sixth before but I moved it to the third to see if that would solve the problem.

The problem:

The temps are more off the higher I go in the rack. In the bottom I can have 89-90 at the hotspot (measured with a Sentry tempgun) and at the higher levels it can be 95+ and sometimes more. Some of the differance is caused by the snake as I use a bedding similar to Aspen, some snakes burrow down to the plastic where it naturally is warmer and some leave it alone and get's the desired temperature. But still the differance (wich is in my opinion too big) is pretty big and I've tried everything I can think of.

Anyone got some bright ideas for me?

Thanks

Correct me if I'm wrong but, Are you saying your heating your rack with heat mats?

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Originally Posted by iCandiBallPythons

Correct me if I'm wrong but, Are you saying your heating your rack with heat mats?

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That is correct.

I would take the heat pads out and replace it with Heat tape. You are going to get a couple of degrees different from the bottem to the top no matter what you do. I would take the snake that enjoy it warmer and put them on the top and vice versa.

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Originally Posted by Henry

I would take the heat pads out and replace it with Heat tape. You are going to get a couple of degrees different from the bottem to the top no matter what you do. I would take the snake that enjoy it warmer and put them on the top and vice versa.

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And why would you do that, if I may ask? Is heat tape the superior heating device? You do understand that heat tape isn't the only way to warm an enclosure, right? And you do know (by Googling, of course) that the Habistat Vivarium Heat Mats are pretty much the same as FlexWatt? Im just saying.

Forgot to answer the question. It bothered (and still bothers) me too, you just have to accept that the temp will always vary from level to level. Best way to go about it is moving the thermostat probe around from level to level starting out from the middle and working down until you get a temp gradient that youre comfortable with.

Well it would of save you money instead of buying all those individual heat mats. It would be easier to hold accurate temps with one long piece of heat tape compared to a bunch of heat mats. Just my 2 cents. Just i think the consensus is to use heat tape.

Quote:

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Originally Posted by Henry

Well it would of save you money instead of buying all those individual heat mats. It would be easier to hold accurate temps with one long piece of heat tape compared to a bunch of heat mats. Just my 2 cents. Just i think the consensus is to use heat tape.

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The dude is in Europe, hence the Habistat products. And as for me, my rack has Flexwatt running in parallel, so it's the equivalent of having 9 separate heat mats, only difference is I wired it myself instead of buyng prewired. Same difference. Saving money is irrelevant at this point, he's already invested in the heat mats.

Like i said before just get the temps as close as you can and put the snakes that like it a little warmer and put them in the top.

My suggestion is check the insulating factor in the rack and where the probe is.. I know the further down the rack the probe is the hotter the top tub is.. so If you have it set about half way and set at sat 95 then the bottom tubs will be about 92 and the tops as much as 100+ depending on the air circulation in the area the rack is in.

Thanks for the replies.

As someone mentioned I live in Europe (Sweden) so flexwatt is not an option, I tried heat cables but that wasn't reliable, hence the heat mats.

Do you think I would get a higher temp in the lower levels if I somehow insulate the sides of the lower levels?

I know everyone does it in his/her way but for me, I don't like my hotspot going over 95...

Thanks

Hi,

I would find the shelf for the probe that puts the most tubs in the right temp gradient and fit inline dimmers for the ones that are still getting too warm at the top. :gj:


dr del

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Originally Posted by dr del

Hi,

I would find the shelf for the probe that puts the most tubs in the right temp gradient and fit inline dimmers for the ones that are still getting too warm at the top. :gj:


dr del

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Is it possible to get dimmers to work side by side with the thermostat or do I need to take the heat mats that are not as accurate as I want on dimmers and the rest on the thermostat? Sorry but I'm not a electric wiz hehe.

Hi,

No you want them all to be controlled by the thermostat to prevent overheating.

The dimmers will simply mean less power gets to the top ones when the thermostat is providing it meaning they will not get as hot.

It will take a little tweaking at first but once you work out the set point on the dimmers the whole system should regulate itself perfectly well under the control of the thermostat. :gj:

Oh and save yourself some heartache by testing the dimmer switches on a lamp first and marking the dimmer in permanent marker with which way is turning the power up and which way is down - sounds stupid but it is a real pain to try and work that out reliably on a heatmat. :rolleyes:

If you test it on a bulb you can see instantly and you then also know the dimmer works. This can save time is you wire it into the heatmat and nothing happens as you know both components work so it must be the connection between em. :D


dr del

I just drilled holes in the tubs on top to allow a little more heat to escape.

Your rack is too HIGH.

Physic 101 : Remember that hot air go up and cold air goes down.

Meaning the heat used to heat the bottom move up and heat the other tubs.

Also, I think the heat mat are less constant than the flexwatt tape. I was using heat mat when I was younger, and I always had difference in temperature when I was switching them. They tend to lose their heat capacity when they get older. But I still have inconsistent temperature on my flexwatt tape, from one end of a shelf to the other end. Not a lot, but still.

One suggestion would be to build rack horizontally instead of verticaly. Let's say, instead of having 6 rack of 12 shelves high, you build 6 rack of 2 shelves with 6 tubs per shelves. And you uses 1 thermostat for each like you would. That should help you get a consistent hot spot.

If you are using an Herpstat Thermostat for your racks, I suggest you go with a PRO version or a model II. They have 4 probes, each being on separate line, meaning that if one broke, the others are still running. And a pro cost less than 4 basic, and you have more option in them.