its a 400watt its all the way to the roof my space is pretty small thats why its so close to the plants, at the begging the plants where miles away from the light but i under estemated how much difference these lights make compared to flouros, iv got 1 input fan just a normal bath room one run for 12 hours on when lights are on then off for the night and i have a oscallating fan aimed at the light on 24/7 seems to do pretty well for keeping the heat away from the plants. maybe not good enough. i would have a output fan but it would give away there hidding spot way to much. the temp meter has a lead in between the plants so it picks up a pretty direct temp