Now i have a plan.
I want to make a terraium with a plexiglas top, where i want to install one maybe 2 pc-fans, i have an idea about them transport the heat from my 2 18w Flouresents light in a custom hood (Color 865 - Daylight) But will this be to much heat? Can the plexi stand the heat or will it melt? And do i need more fans inside the tank to move the air around?
I will be growing orhids that need intemidate to hot!
Question: you still plan on building something about 30 cm x 30 cm x 30 cm? In that case 2 x 18 Watt might be way too much light for a lot of orchids. What kind of plants do you want to grow?
The tanks that I have that use similar (I'm assuming self-ballasted) lamps get as high as 29C without bringing air from the hood into the tank- air is circulated within the tank, but is definitely heated by the lights.
The plexi wouldn't melt, I don't think, but it may bow a little- you may want to use glass or a thick, rigid plastic.
I have my lights, 4 2' fl tubes, in a separate box above the main case. I mounted a sheet of 1/4 plexi separating the lights from the growing space. When I set it up the heat from the FL fixture was too high for my taste so I mounted two dc pc fans, one at each end of the fixture. There are doors venting the separate light box which remain open all the time. One fan pulls air thru a door and over the bulbs and the second pulls the hot air out the door at the other end. The temp with lights on remains at 72 - 75f at all times.