No I was not saying that a digital ballast not good for a closet room,

What I am saying is the actuall ballast has to be placed in a cool place with good air flow. You can put it in your grow space if you have good ventalation and the temperature never goes above 80f. Also the ballast has a cooling fan and if there is any restriction in air flow it may overheat the ballast. I also don't recommend setting it on the floor exspecially carpet. Carpet is an insulator and will cause heat buildup.
The way I have mine is hanging from a screw on the side of my cabinet with 1" air space between the ballast and cabinet so air is flowing freely on all 4 sides.

As for attic growing I do not recommend using a digital ballast for this due to the extream temperature fluctuations. I don't even recommend growing up there at all.
Jerry Garcia 2007 Reviewed by Jerry Garcia 2007 on . digital ballasts? advantages? i just bought a 600w HPS "digitally ballasted" light. Unlike other HPS lights ive seen, the ballast is about 30x10x15cm and is connected directly to the light so its all one unit. does anybody know the advantages that these lights have over....not digitally ballasted lights? :hippy: Rating: 5