the closet is behind the air handler there is a panel to access it inside my closet, if the heat or air or just the fan from the unit is on it pulls air very fast, and i can get 8 inches from top of plants with 400w hps without burning.my only question is how would i find out how much the ""FAN" function on the ac is to operate? it works almost too good could probobly lower 2 more inches sounds crazy but true!!