Hey Starzy,
Yes to all you ask..lol.
You need intake air to cool the room AND it must exchange the entire grow chamber approx every 5 minutes.
You need to exhuast out hot, stale air.
You need to circ the air while it is in the grow chamber.
Simplified outline: Use one fan as your exhaust, but make the intake ports far away from the exhaust fan so the exhaust will pull air into the chamber, the circ fans will make it dance with your girls and eventually the exhaust fan will remove the air. Intakes are low and exhaust is high (warm air rises, cool air sinks).
Another fan is usually used stictly to pull light heat out of the chamber, but not knowing your set up this may not be true.
Hope some of this helps,
Kayuman