dding intake and exhaust fans is a crucial step towards effectively keeping your components cool. But intake and exhaust are just the beginning and ending points of the cooling process. To ensure that your setup effectively keeps your system cool, you must take into consideration the entire airflow path from its origins outside the cabinet, on through all the corners and turns of its passage inside, to the escape and final dissipation of the warm air back outside.

Add speed to the airflow

As much as possible, make sure there is unobstructed space in front of the intake fan. This will significantly improve the fan’s performance. By pulling the air in a straight line across an empty stretch the fan is able to give the incoming air stream a higher speed. Speed helps the incoming air overcome obstructions inside the cabinet that create resistance to the airflow. The higher velocity also increases more air turbulence inside the cabinet. To a certain extent turbulence is a good thing, because it helps flush hot air out from small nooks where it might otherwise collect.

If possible, also allow some unobstructed space on the inside part of the intake path. If the air flows in at high velocity, but is then made to immediately turn sharp corners on the inside, the result will be excessive turbulence. Too much turbulence creates “noise” and vortices in the airflow, which decreases the speed of the airflow and reduces cooling efficiency.

Use low-temperature air

The lowest temperature air possible should be directed through the air intake. If at all possible you must place the intake fan where it takes in ambient, room temperature air, and away from room heaters and the exhaust path of other equipment. The optimal place for an intake fan is somewhere in the airflow path from the A/C system.

Avoid taking air in directly from an A/C unit, however. The temperature inside the cabinet must not drop below the “dew point.” Otherwise condensation will form on your equipment, which may lead it to short circuit.