Heat distribution in upright racks?

[Tim_Cranwill]

I have several melamine racks with heat tape running up the back. I have found them to be great space and time savers. However, I find that even with the back of the rack insulated with Styrofoam, I get a pretty wide temp range from cage to cage in the same rack. I have found up to 10F difference from the top cage to the bottom cage. I know that heat rises, but this really sucks!

So, I wanted to see what other people have experienced with these racks and what, if anything, you have been able to do to remedy this situation.

Thanks! :)

[marisa]

Yes! I have this problem HUGE! No matter what I do, no matter what heat source I have used, how much insulation, I get a huge range of temps from the top to the bottom.

Bottom cage will be a nice hot spot of say 83-85 while the top hot spot ranges in around 88-94. Basically when I asked before people here said to get more circulation of air in the room the rack is in itself. I have tried this and it works to some degree but not really.

For now, I just keep some colubrids on the bottom and my Ball Pythons up top :) When I build new racks this summer I will have each section of four cages controlled on its own to hopefully avoid this problem.

Marisa

[Ron]

I think you are S.O.L., I too ran heat tape down the back of my racks and experienced the same kind of heat differences. Luckily I made them deep enough that I could even out the temp by adjusting how close they were to the back. I've since changed my design to several pieces of 11" on the back so I have control of every 2 levels. More cords but definitely worth it to have the control.

[Reptile Kings]

I absolutely hate running heat tape along the back of any of my racks, used it before, and saw big time temp. fluctuations btwn each level on the rack, even though it was well insulated and such. To put it simply, there really is no way around it, the bottom will always be at least 5-10 degrees cooler than the top.
That's why I now prefer installing heat tape on the bottom of each container of each level of the rack, works much better.
My geckos seem to like it more as well, as they're getting direct belly heat.
-Sam

[crazyboy]

you could hook every couple levels up to a dimmer and then all the dimmers to a thermomostat. the thermostat will keep the rack at a certain temp while the dimmers can adjust the temp. on every few rows so that the thermostat keeps the temps on all rows the same.

[vanderkm]

We have had a similar problem but have no shelves near the bottom (storage under the lowest shelf about 2 feet off the floor) and we split the rack so that it is heated by two separate heat ropes, each on it's own dimmer switch. There is still some variation within each level, but we have the older, larger snakes in the bottom level and the younger hatchlings that are being fed more often and need a bit more overall warmth are near the top.

If I was to build another rack, I would definately plan on having two or three separate zones, but I like the heat going up the back because it doesn't get rubbed on by the tubs going in and out.

mary v.

mary v.

[Stockwell]

For good control you need individual strips of bottom heat(flexwatt) on each level with mulitple dimmers for every 2 or 3 levels max, depending on the size of tray/spacing.
If you want to cheap out on less dimmers, try moving the pieces of heat tape further to the back of the shelf , and away from the trays at the higher levels... This is effective with ventilated or open back racks.
Even done like this temps will go up and down with ambient room temperature shifts, and line voltage changes.
The only way to get good tight control on Flexwatt heated racks is by controlling the room ambient so it is constant, or by having actual thermostatic controllers for each level that monitor the actual tray temp and either cut back on the heat by either switching it off and on, such as what happens with normal thermostats, or by phasing back the AC which is what is done with solid state proportional controls, such as Helix units

[JRQ]

Alright I'm a little ignorant in this subject. But I am planing to make a tank out of plywood would it be best to heat the tank from the bottom, the back, or the top? I would like to avoid the top. ANd would i best use a flexwatt , conscern since it is a wood tank. Also, as a last resort would i use a ceramic heat emitter for the top with a glass top or a plexiglass top? Also, this tank is for frogs and it will have an automatic misting system, the ones that use the bucket, timer, and pump. This may be a problem saince I might need to make holes in the lid for the heat to enter the tank. So tell me what you guys think. If needed I will be willing to draw up plans.

[retic]

i agree with reptile kings and stockwell, i only use belly heat on each level as well with dimmers on every 3 levels like the units i built for reptile kings and loving leos

[mykee]

Check out my gallery to see how I wire my heat tape to avoid any temp problems in my racks. Works like a charm for me. Hope it helps.

[BoidKeeper]

Rim I beat the problem with my ambiants. If I want the cool side to be 80, I heat the whole room to 80 and adjust the hot spot to what ever.
Cheers,
Trevor