First off the heat to light ratio is worse for cfls, and you wont get the same amount of lumens per watt. Plus they cant be air cooled. The reflector you are showing is air-coolable so you should either run a 6" duct fan through it (cheap and loud) or a centrifugal fan (more expensive and quiet). Do that and you'll be able to stick you balls against the reflector glass with no prob (wouldn't recommend this). That digi ballast will emit minimal minimal heat with a 250. As far as sticking the reflector on the top of the cab, just watch out for light leaks, and dont start a fire!! If I were to put the reflector on the top the of cab I would be sure to air cool it. Good luck and peace
BlazeIdo Reviewed by BlazeIdo on . NEEEEEED HID OPINION! Ok here is the deal.....below is a picture of my 3' tall cabinet and the 250w hps system i am considering buying...I have this idea where what i will do is cut a square in the top of the cabinet so that my HPS reflector can fit snug right over the hole....the ballast will be at the top of the closet on a shelf about 3 feet above the growbox....i have two fans 120mm computer fans already installed in the box one at the base of the plants and the other at the top of the box....not comming out the Rating: 5