heat concern: 400watt hps in a closet, solutions?

i was going to use a 150 or 250 watt setup, because i cant really have an exhaust system for this closet grow. so i am worried about the heat. but i keep reading that if you dont go with at least a 400, you will be disappointed...

it is for 2 or 3 plants, and the closet is about 4' wide x 6' tall x 2' deep.

will a 400watt make this space way too hot? would a 250 be better, and throw significantly less heat? note that i may be able to have the ballast outside of the closet, to reduce some of the heat problem. is there even a very big difference in terms of how much heat a 150 or 250 watt bulb throws compared to a 400?

i can put a fan in the closet but it will have no source of fresh air - for intake or exhaust.

thanks!

it should be ok if you make sure you have air circulating(fresh air) and maybe if you keep the door open for the 12 hrs while the lights on. is this for flowering or veg.?

both probably...

Yea man, as long as you keep the door open and keep some fans in there that will be circulating the air, you should be fine. Also, keep your house/apt fairly cool, as this will help a lot.

I got a 400 watt MH in my closet grow room right now and it never gets above 82. It has reached 84 before, but this was only for a little while as I had just closed the closet door.


**update**

Oh yea, don't forget to keep the door to the room closed. I also closed most of the vents in my apt so that more cool air blows into the grow room.