If you have a Fully Enclosed Server Rack, there are two factors to determine if you need a cooling fan. The first is the amount of perforation that the doors actually have. The server manufacturers like Dell, HP, and IBM require a minimum of 63% perforation on both the front and the rear doors. To calculate the door perforation of a Server Rack you should use the following method.
- (Rack Units x 1.75″) x 17.72″ x .63
Note: 17.72″ is the standard dimension between the Rack Uprights.
This formula will determine the minimum amount of perforation required by the Server Manufacturers.
To determine the amount of perforation of a specific Rack Door you should use the following method.
- Perforation = Number of Holes x Area of a single hole
If the door does not meet the minimum perforation requirements then you will need additional cooling fans.
The second factor is the airflow of your servers. Most modern servers have air intakes on the front of the servers and exhaust ports on the rear. The intake and exhaust air should never be allowed to mix. To prevent this mixture of air all empty spaces in the front of the rack should be closed off with filler panels. Once this separation of air is achieved then the room AC will accommodate the cooling. If your equipment does not have front to rear airflow but instead has intake or exhaust ports in other locations then you will need additional cooling fans.