Hi, I have a 600w HPS bulb in my 140 x 140 grow tent on a dimmable ballast. In my tent I also have a very powerful 6'' exhaust fan, with carbon filter drawing the stale air out of the tent. I also have two oscillating fans in there and a 4' intake fan making the room cool. The 600 w HPS bulb however gets SO hot the temperature in the tent rarely gets below 30 degrees, and probably a little higher at exact plant level. It is so hot I have to move it very far away to get any real growth, so resort to using the 400w setting. I understand ventilation etc cools the tent down, but simply the temperature given off by the bulb is too hot. Does anyone else have this issue? How else can I cool the tent down or is it just a problem with HPS bulbs? Thanks
Everyone has that issue; they use AC units. You need to use a reflector that encases the bulb in glass which is set up on its own. I got one kicking around... no use for it since I went to LEDs. These guys show what I am talking about.
I think this is why HPS is dying out and making way for LED. If heat is a severe problem, look into getting some quantum boards. Good luck!