Those would heat the room; the lumen loss through an air cooled hood is minimal and the benefits of a cooler/coolable light far outweigh the slight lumen drop. Keep the lights as close as you can before seeing heat problems (upcurled leaf edges and/or pale striping between veins). I can run my air-cooled lamp about a foot closer to the canopy than my non-air-cooled one; you will have to find that sweet spot for yourself.
Your footprint should fall between 4 and 5 feet.
stinkyattic Reviewed by stinkyattic on . 1000 HPS question? Hey Guys - I have 2 1000 watts lijgthing 5 x 10 ( room is 11 x 9 though) My ilghts have glass shielding and cooling with 745 CFMs... My question is, how far away should i keep my light from my plants since this galss ruins the lumens... should i even use this glass... and how far does the footprint of a 1000 go to with using this glass... I was hoping to get at least 5 x 5 per light... but not sure with this glass blocking some lumens... would 2 "glassless" lights heat up a room Rating: 5