new grow room vent questions/ co2

sup people, i have a few questions about setting up a new grow room. im not new to growing but new to growing in a bigger area. i have had some grows under my belt in a closet but now transferring to a new environment. now im moving into a condo and i have a room dedicated to growing. what i want is a 4x8 room for flowering (12 plant) and 4x8 for veg. im going to part the room with panda plastic and was just curious about venting. i was thinking on venting just the lights to the outside window to cool them and was thinking about using co2. do i still need fresh air intake if i ran a co2 setup? i am going to exhaust with a hefty carbon scrubber with the vent going outside also. do you think if i directly vent out side of the window that there still will be an odor coming out?

oh and if stinky is watching can you remove this post below? i put the same one up in a wrong category.

http://boards.cannabis.com/closet-ca...tions-co2.html

ive been reading and searching and came to a little bit more knowledge. so now my new question is, if i ran bottles of co2 in a completely sealed room do i still need to have an intake and exhaust of air or can i just have the co2 setup and just fans inside circulating it around.

From my research co2 will allow the plants to do well up to 90deg temp's. My 250w mh would get 90 deg temps air cooled and recirculated, no ventilation, sealed room. I'm going to run ducting btw the walls into my other bedroom. hopefully that will keep the temps down.