@ Matthebrute: Yeah didn't think about that... I'll insulate the area around the lamp with rockwool or something like that. It is hanging, it's just really close to the ceiling right now. Thanks =)
@ OPM: as I wrote, the air will be vented to the roof.
Hey,
I'm planning on starting a grow in a small space under the roof. Total usable growing area is about 1m * 0.6m, with a height of one meter from the cooltube (with 250w HPS) to the ground.
I still have to add the oscillating fan and a transformator to eliminate fan noise completely, and...