Basement with no intake airflow?

Okay my question is this:

How worse off will I be growing in a basement that will have no fresh air coming in from outdoors? The only thing it will have is the home's built in air conditioning unit.

I'm going to have lots of fans from different angles for airflow. I'm going to have the exhuast going outdoors or to another part of the house.

I can't think of size dimensions so I'll throw out 30 ft. by 40 ft. is the basement size.

It's also going to be a fair amount of watts (so a sealed grow is out of the question because i need to exhuaust lots of heat). So if I'm able to keep the room temperature down, how much will the lack of incoming air hurt the grow?

Will you be using Co2?

iloveyou

I was hoping that to be the case fatsax. Can anyone else verify this?

No, I'm not using C02.

you'll be fine..just control the heat but if you can inject co2