the intake hole/holes should at least equal the size of the exhaust

if you were active intake you might beable to get away with a bit smaller intake but i dont know that forsure. what i know is the more fresh air the better

i would at least try an 80-100cfm fans instead of 34cfm fans
texas grass Reviewed by texas grass on . Lowering temps in cab.. couple questions! Ok guys, I have a cab 34"(h)x24"(w)x15"(d). Temps are getting up to 90-95 in my cab with the door closed. I have an oscillating fan inside the cab for airflow. The outside room temperature stays around 70-72. Right now I have 2 - 3" Dynex comp fans (80mm / 34 cfm) running as the exhaust out the top backside of the cab placed side by side, and a passive intake at the bottom which is slightly smaller. I've tried a couple diff. setups; using one fan as exhaust and the other as active intake, Rating: 5