grow room design ideas !! help plz

my room is 11' by 7' and 7' high. i want to build a wall 4' in so the grow area is 7x7x7 and is sealed off for smell. i have a 1000 watt SunSystem switchable balast with HPS and a rectangle reflector with two 4 inch holes on the side for venting . i am not sure what kind of fan i need but something around 100-300 CFM ,if thats enough to vent the heat. i will have regular house fans blowing a little over the plant, wondering if this will be enough? or do i need air from outside the room? i will run the exaust to the top of the new wall and have a carbon filter on the other side of the wall. i live in a cold place so i know heat wont be a problem (other than the heat from the light) but i was wondering if it would be possible to just run exaust out of the room, and not having air coming from the outside into the room. the main questions i have is how much CFM i need to vent out a 1000 watt and what kind of fan/where i should get it and if a 4 inch fan is big enough?

any ideas/questions/comments would be very much appreciated.

Well when exhausting air out of a room, the room doesn't just become a vacuum. Air will naturally enter through any crevices in the wall. If you are really going to seal the room as much as possible, look into CO2 releasing devices. There are a lot of fans available and they aren't measured movement wise in their width (4"). Since you say you won't have much of a heat problem, and it doesn't sound like you will with just the one light and a cold climate, That one fan may be enough but I would suggest doing some duct work inside the room so the intake for the fan is in the middle, and add some oscillating fans around the room.

if possible sell the 4 inch hood and get a 6in or larger vented hood and get a 350 cfm or larger vortex fan. if not possible home depot has 6in to 4in reducer to vent the light. i would recommend 2 1000 lights in a 7x7 room. i have a 10x10x8 room with 4 1000 hps and 90+ ladies with a sea of green producin over 8lbs every 2.5 months. More light more weight. If you dont have central air you will need an air conditioner in the window or a portable due to radiant heat from light/s. also dont dick around with soil indoors get a flood and drain system loike a 4x6 botanicare tray and 70 gallon reservoir and 6in rockwool cubes and get a good strain. do the research and ask for samples. I use conniseuer by advanced nutrients and get better yields than anyone i know using anything else out there.

thanks for the help ya i ened up geting 2 6" vortex and have a reducer on the hood pulling out air and have the other on sucking air from the outside thru a window screen also have a speed controlar on that it work really well and also have about 400 watts of cfl and led on snake lights right now ..but selegrath how tall is flood and drain system cuz im limited on hieght and i also grow completly orgainic with lots of local soil and soil fertal;izer mix can and what woudl i use if i went flood and drain and i have mazar-i-sharrif crossed with blue goo and mazar-i-shariff crossed with bubbakush/norther lights so those are my strains for now