250jps or 400cooltube, which is cooler?

I'm new to this, and cant seem to find an answer anywhere. I was wondering, what would keep a grow tent/closet cooler, a 250hps or a 400hps cooltube?

i would recommend a cool tube no matter what size hps or MH light you choose.
even a 250 watt will heat your tent without one
and since more is better when it comes to lighting i vote for 400 watt cool tube

400w cooltube the price is not much of a diff either .

cool,
and when venting from the cooltube, does that suck air from the grow chamber out as well? so its an exhaust also. or do i need a separate air-out line to keep the air in the grow chamber circ?

only if you dont put a hose of duct on the other side and suck air from the outside of the tent.
It's not much of an exhaust if the fan is weak.

Iv heard nothing but bad things about a cooltube, use a conventional air cooled hood with outlets and a swinging tempered glass window, you need to clean it sometimes remember, how the hell can you clean the inside of a cooltube without removing the light? Dust drops light xmission.