Yea the closed boxes are mainly for warmth. I keep them in a middle room of the shop, that only gets moderately heated- sort of a breezeway for the main heated part. I'm not sure if the lights put out much heat really, but it does seem to stay warm. I laid some foam I had saved for spacing trays up closer to the lights on top to somewhat aid in insulation perhaps.
These are my early starts, trying to keep it limited!
I think I might wait and start the rest in the greenhouse once the temps are ok.
