Is this fan okay for a 4x4?

Hey. I currently have a 200cfm fan that I used to use for my 2x2 running in my 4x4.
So far no issues that I can see.
Every so often it gets into the high 80s, like 89 degrees f but that's not too bad.
My only concern is that I may not be drawing in enough fresh air for the plants to do as well as they could. Maybe I'd get higher yields with a diff fan, etc.
Is there any legit reason to buy a 400cfm fan with a controller or should i not spend the extra $70 as it's not necessary?

Thanks.

Zack

It will help you to keep heat down if you need it. I run a 6 inch 350 vortex fan with scrubber to keep at or around 80 degrees F with 450 watts of light.

Good for odor control and exchanging the heat out.