Ventilation 400w HPS 4x2

I plan to start a closet grow with a 400w hps in a 4x2'' closet, ive done some research and havn't got any solid info about this exact set up, i know 4x2 400w is fairly common so anyone with experience with this could help me out... I was wondering what temps i would get in the closet without any exhaust hole flowing air out of the room, because i would have to put a hole through the wall to get into the crawl space next to the room. If i could possibly still be functional with only in-room air movement? Also how much does an air cooled lighting fixture help the temperature?any other suggestions also welcomed. i would have to go through the right corner.

your gonna need a way to cool the light down. dont try to cut corners just cut holes man unless your renting?

Nah it's ours, just wanted to make sure i have it the right temperature. I was thinking using that 6'' tubing to go from the bottom of the closet, through the light and through the wall. Would that be enough? (Plus a fan or two) with a inline fan on the other side of the wall also.

Yea, your definitely going to need some type of exhaust. Especially in that small a space. The difference between a Cooling tube and not, is like night and day. I currently run a 400 watt MH for veg, in a room 6x7, and I need exhaust, or my room would be over 90 after the first two hours of an 18/6 cycle.

My space is EXACT SIZE and let me tell you it's gonna get HOT on there with no ventilation. Exhaust helps but you will need a intake as well. I use at moment 190cfm that goes from can filter thru cool tube thru fan and out then ducting runs out the window. Getting that hot air out of closet is first but IT HAS TO GET OUT OF ROOM if not you'll just make it hotter in closet. For intake I only have 100mm computer fan so that's a 4" fan with another oscillating fan inside. Before ventilation I was ranging from 94F low to 104F high!!! That took me all of an hour to see and I hauled ass to store and got my shit together. Now low is 70F (cold outside now that's bed time temps) during the day with lights on highest it gets is 84F. So helped a lot with only $100 bux but need a booster fan for intake. Those run about $25 US dollars at home Depot or anywhere like that. With the booster I should get to the 76F I want to be at. My plants seem to like my temps tho thought day it goes from 79-84 but they don't curl or anything. They seemTo enjoy it but still would like to see their behavior at consistant lower temps. Try to blow up my profile pic and you can see the basic setup. For some reason it won't upload my pics into album or threads. GL and hope it works out for you. Oh btw I don't have a 400 I have a 600 watt hps setup, well the MH in there at the moment but in another couple weeks going back to HPS. Hope that helps some.

Thanks for all the info, it really helped sort everything out. basically to sum it all up is: Get a small intake, use the cooltube and then exhaust into another area with an inline, and have a fan in the room and with that i should be getting 70-85 degrees F and booster fans help. Also: i would need to take out part of the door or another part of the wall for intake, do i need intake for this setup or can i just siphon from in the room and push through the light and out the hole *or can i just keep the door cracked while the light is on for the extra intake