Blow air in or vent air out?

[njohantgen]

Which method is more effective for cooling an enclosure, blowing air into the enclosure or venting (sucking) air out of the enclosure?

[omsupport1]

The main points to consider when using a fan for ventilation and cooling are:
-The airflow path should be as uninterrupted as possible. Air should flow over/under the item(s) to be cooled. The air should not be forced to try to flow through the item(s) to be cooled.
-Make sure that the air flow path is not so short that it allows any air elsewhere in the enclosure to remain stagnant.

If the above conditions are met, there is no real fundamental (theoretical) difference between blowing air in or venting air out. However, in the real world, venting air out is more effective at maintaining stable internal enclosure temperature.