MegaOctane makes a good point; a fan moving air around in a sealed space doesn't cool anything, it just evens out the temperature in the whole airspace. A circulation fan's motor will be adding heat to the air to boot.

Air has to be brought in from outside the grow and exhausted somewhere else, where it can not be easily re-drawn into the grow.
Al B. Fuct Reviewed by Al B. Fuct on . Keeping temp down So im going to be starting my first grow soon and im not sure if im going to have a temp problem. I live in Florida so it stays hot here and I havent ran my AC in about 2 years. I'm going to have plenty of fans on my plant ( only plan on growing one to start out with) but I was wondering if there was some cheap and easy ways to get the temp down during the high points of the day. For instances , i'm going to be using somthing like the rubbermaid box setup but with 2 big trashcans instead so im Rating: 5