sorry I am late in responding been out working in the yard
The Orchidarium does have a piece of plexiglass or something like that between the lights and the orchids. There are two sliding doors in that you can open to regulate the amount of heat there is also a vent on the very top of the unit to allow heat to escape.
The front door is of similar material and it slides back and forth. No more wheels. It is very clear so it is hard to see on the Orchidarium website.
My unit maintains apprx. 80 to 90 % humidity and the interior temps usually 80 to 85 degrees. At night I open the front door a bit and open the top vent to allow the temp to drop the 10 to 15 degrees they need.
The orchids in there are putting out new growth as well as tons of roots and they are lovin it as much as I do
Sheridan