::1) Can a thermostat like this also be used with an under tank heater? A ceramic heater?
Yes for both, but the position of your probe is very important with an UTH. UTH's are primarily used to provide a warm surface or in some cases to heat the air of a hide box that is placed over that warm spot. Slight shifts in the position of the probe/sensor can mean a dramatic temperature shift of the actual warm spot when used with UTH's or heat tape.
For this reason I prefer to use rheostats for UTH's, whether they be made from Flex Watt or are a prefrabricated product (such as ultratherms).
I think I'm in the minority on this, though, and look forward to hearing other responses. I know thermostats are used with UTH's but the results of my testing with these combinations has not been very confidence inspiring. In fact it's scared the heck out of me when it's come to flexwatt.
There are cases, such as in Boaphile cages, where the UTH does such a major job of providing all the heat for the cage (vs. just a basking spot) that a thermostat is again appropriate.
They are ideal for ceramic heating elements and radiant heat panels. They are also useful for racks heated with heat tape. In racks it is easy to set the probe outside of a box where it won't be shifted by a snake. Even in this case you have to experiment with a probe position that provides generally stable temps in your tubs.
::2) Anyone have any advice on how much heat is lost by a ceiling mounted heater as the cage height is increased?
Quite a bit. I think providing both an UTH and a ceiling mounted heater is appropriate here. Do not put the probe in the middle, though. Better to have the basking spot the actual temp you want and let the conditions in the middle of the cage fall where they may. Should not be too bad unless your room is cold.
Think of it this way. If you set the probe 2' away from the heater and set the temp at say, 82* F, you may have a perfect basking temp up high for parts of the year. But during colder months, the heater may have to run so high to heat that middle area to 82* that the actual basking area will be over 100*. A JCP will avoid those temps. Conversely, during the warmer months, the basking area may essentially be shut off during and the no part of the cage will exceed 82*. Not exactly ideal for a JCP, even though you will likely provide a terrestrial basking area.
Probe/sensor placement is very important and requires you to monitor your cages throughout the year. A thermostat should not be purchased to "set it and forget it".
I've seen too many people dump hundreds of dollars on caging and heating elements and then wonder why their snake(s) spend all there time as far as away from the basking area as possible. All to often it's the sensor placement that is causing the heating element to run too hot.
::3) Are UTH's OK under plywood or do you have to trim the wood down real thin to get any heat through?
Neither is a good idea, IMO. If it were me I'd cut a square or rectangle out of the floor of the cage and cover the entire floor with expanded PVC. The UTH, obviously, will be placed within the cut out rectangle. This will make for an easy to clean floor but one that will also conduct heat nicely.
::4) Any rule of thumb on vents and their placement depending on cage size?
Absolutely not. Where you live, the temps in your room, and, most importantly, the species you keep determine how much ventilation is necessary. I always build my cages with excessive ventilation and then cover it as necessary. Easier to reduce ventilation in an aesthetically pleasing way than to add it when you find out you don't have enough.
For most species consider increasing frequency of mistings or providing high-humidity hides rather than reducing ventilation to the point in encourages microbrial growth.
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I currently have a Big Apple thermostat connected to a ceiling mounted heat panel in a 4x2x2 wood cage for my Florida Kingsnake. Thinking about future cage projects and I was wondering:
For example, I'm planning on building something around 4 feet tall for a Jungle Carpet Python so he has plenty of climbing room but I'm worried it won't be warm enough down on the floor of the cage. Could I run a ceiling mounted panel and a UTH on the same side of the cage into a thermostat and put the probe somewhere in the middle?
