hid lights

Are so hot! What do y'all do to keep em cool? Ac with a fan per light in air cooled hoods and they're still hot.

air cooled hoods

Southerner said:

air cooled hoods

Click to expand...

Air cooled hoods are a given but it seems like they don't do much if theres not freezing air going into them.

What type of fan and how many CFM? How many watt bulb?

I cool my 600w with one of those cheap inline booster fans for $30 (240CFM) and the hoods are cool to the touch.

200 CFM PER 1000 watt fixture.
Daisy chain NO more than 3 Without WATER cooling the AIRLINE.
easy way is a six inch active air inline fan per chain pushing the air . adding a air robber to the end sometimes helps with turbulence.
if your sealing the room using c02 and ac i mini split or bigger is the ONLY IMHO way to go reccharge as needed.
click on "my little grow thread" in my sig an you will see i use a 10000 watt window unit in the winter . that was so i could HEAT my basement in the winter with the off heat (not reccomended)
i have since upgraded....
YES cold air is best but running lights at night is best and ANY coldish air is fine if a AC handels the temps.... pricey but so is the meds.....

I'm a cheap ass, Grow in the winter and Outdoor in the Spring. A regular fan with a window open can keep a small 3x3 grow room well ventilated. It sounds stupid but it works, I get 2 to 3 ounces per plant under my 400W. Long as your seeds has the Genetics, Brown Hard Tiger Stripes, More Tiger stripes the better. you will have top shelf.

Thanks yall for the info.

How hot is it at plant top level?

go CMH

Get a better hood and exhaust fan.