There's only one way to really do it, Inlet fan as low as possible, exhaust fan as high as possible, the hot air needs to vent some where it wont just get sucked back in. Like its pointless to have a grow box in a sealed closet, and have a fan on the bottom and top of the box, the closet will eventually get hot and you'll be blowing hot air back into the box. Fans that just blow air around in the room dont do anything but push hot air. U need to get the hot air out, and get the cool air in however possible, its your space.