1. Rain, bugs and cold air will get in if you make a hole for your wires on the bottom like that. Plus the tortoise will have access to them and could bite the wires or rub the insulation off over time. Much better to run that up high, out of reach. I run mine under the lid and incorporate a drip loop, so when it rains the water all runs downhill and away from where my cord enters the box.
2. I build a lip around my lid to keep rain and dust out and warm air in.
3. I would not use a CHE on the floor that way. Its just a question of time until something makes contact with it. A leaf that blows in, hay, or your tortoise. It would be much safer to mount a fixture higher up on the side or ceiling. And a single CHE might not get the job done. Only your thermometer will be able to answer this question. For a warm night box al the air in there needs to be heated to a certain minimum. You don't want a "cool" side and you don't want your tortoise cooking under a CHE trying to warm up because the air is too cod in the rest of the box. This is exactly how carapace damage occurs.
You can attach fixtures to the roof of the heated box, even if it is hinged.
In this case JD uses a porcelain light fixture. With enough height, you could use a black bulb, for example. http://www.tortoiseforum.org/thread-59019.html
However, as Tom mentioned, a single small fixture might have trouble heating the whole box, so could focus too much heat on the tortoise shell, and also, JD's enclosure is in inside another shed.
That's why I think the Radiant Heat Panels are a good solution; more diffused heat. Then the mini oil filled radiator for background heat; they really are efficient.
*sighs*
Okay so hole moved.
I really want to make use of the CHE. I'll probably end up buying a Osbourne heating pad. Will that work with the CHE? If i mount the bulb to the wall near the ceiling and put the mat on the opposite side, will that work?
One thermometer for the entire box should be sufficient. Sometimes I have two remote sensors in the night box. One is a temp only sensor that I leave on the floor. The other is temperature and hygrometer that I hang from a shelf over the "sleeping area". It's the one that I pay attention to when determining thermostat settings.
I would use one thermostat to control both of your proposed heat sources. Use either a heat mat and radiant heating panel or a single mini oil filled radiator. I think that in a 4x4x2 foot box I would prefer the former and in a bigger box the latter would work best. As for the CHE, I really believe they can be more of a problem than a benefit in an outdoor box. Maybe send it to Tom for use in a closed chamber for his hatchlings. With larger torts it just creates too much of a fire danger or a shell desiccating hot spot. They are also hard to mount in a 2 foot high box that opens from the top.
+1 on the radiant heat panel. I have one in my sulcatas night box and it works very well without the worry of burning the shell or starting a fire. If you put your hand under it it feels like it is under a CHE except you can touch the panel itself and it won't burn you.
Just putting it out there.
The night may be young, but sun is long gone! I would try, but I may end up with my hand nailed to a board. Oh yeah, and I havent bought any of the wood.
It's all the rage. All the hipsters in Hollywierd are doing it. They match the multiple ear, nose and lip holes. Most add a plated precious metal hoop or post. Be a trend setter in your area, Tiffany.
Construction day has come at last!
Its a beautiful day to build.
I will be taking pictures all through the process and plan to post them when the day's work is done.