Passive exhaust tips

I'm pretty much done building the room. It's 11' x 17 feet. For now I'm gonna run one 4x8 tray with approximately 1800-2000w. Eventually adding a second tray as I get used to my new set up.

I'm gonna be running an in wall AC unit/Fresh air intake plus Co2. My plan is to keep the exhaust system simple. I don't have to worry too much about odor so I don't think I'll need a filter.

The question is:

How big to make this hole?

2 holes?

One on each side?

Or do I just put in an exhaust fan?

I'm thinking passive because if I'm pushing in 1000cfm of fresh air I may struggle to find an exhaust fan to keep up. I sort of like the idea of just a hole and air naturally pushing out.

The room will be sealed pretty well. I don't know what the CFM rating is for these in wall units but my guess is it's near 1000 or more CFM.

Your thoughts?

what about your co2?

My buddy is setting that up. I'm new to indoor. I've helped on many grows but the finer details are going to be a learning process.

His set up is not controlled by a brain. He has it on a timer and it comes on about 15min before the lights come on. I'm sure he has some sort of calculations for all this... His yields and quality are fantastic so I really have no desire mess with the bones of it. But before he's gonna come down to where my grow is I pretty much want to have everything built out so we can just dial everything in.

i used heater vents for central heating. i think they are 6 X 14 or something. i used 2.