thanks for the quick replies guys. the closet is about 3' x 3' x 9' high (possibly a little wider/longer, but from memory this is my best guess). he cut a hole in the ceiling of the closet and is putting in a fan, which extracts into the attic. the problem with ventilation is, there is no intake. i thought maybe cutting two holes, one fan blowing cool attic air in, the other blowing out...? he is set on using a HPS, but i know how hot HPS get. Could you further explain the 'cool tube' cooling idea?
BiGGj18 Reviewed by BiGGj18 on . heat differences: 250w or 400w HPS? A friend of mine is starting a small closet grow in which the ventilation issues could be a problem. ventilation will be somewhat limited, so heat is a concern. He is about to purchase a light, but is unsure which one. He is sure of a HPS system, but wondered if 250 or 400 would be better. Its a small closet so he will still have plenty of lumens with a 250w, but 400 is obviously better. Our question is, how much of a heat difference will there be between the two bulbs? Is the 400 much Rating: 5