Air Based Cooling
A modern datacenter features a variety of IT equipment that generate considerable heat. The enclosures that house these devices (such as servers) often employ “forced air cooling” in which a cooling effect is achieved by taking in large amounts of ambient cool air, which is freely available inside a datacenter. The advantage of an air cooling system is considerable, since a server can be moved and installed anywhere in the datacenter.
With air inlets in the lower portion, forced-air-cooled equipment could prevent the re-absorption of hot air from the hot aisle, thereby improving air conditioning efficiency.
If there is more air being forced into a system than is being pumped out (due to an imbalance in the number of fans), this is referred to as a ‘positive’ airflow, as the pressure inside the unit is higher than the pressure outside.
However a balanced, or neutral airflow is the most efficient.