Ventilation and CO2 Q's....

I'm setting up my room but I dont really have access to "fresh air". I have a CO2 setup with ppm meter, do I still need fresh air coming in? I will have an exhaust for the air to leave the room through a carbon filter. I also would like to use my air cooled hoods for the lights, but is it even worth it to buy the fans if I dont have air from outside the room running through? Please help..... Thanks

where is your air coming from? recirculated hospital or prison air? jk. id say that if youre plants are growing ok, and humidity stays in check, then the air should be ok. i myself have an exhaust fan that feeds air into the room every 40 seconds from outside. but i have no CO2. i have air cooled hoods too, but im planning on attaching small duct booster fans directly to them while they travel on a light mover.

damn no one wants to help me out huh...

You should have fresh air coming in. But if you can't change that, run the hot air from your lights directly out the room. And buy a lot of oscilating fans.
Good Luck!!!

thanks dude, I'm going to see what I can do to get some air coming in.