The Design and Organization of Data Centers/Air Conditioning

Sizing
Air conditioners are rated by tonnage. One ton equals 12,000 BTU per hour.

Equipment heat output is rated in BTUs.

Conversion rates and guides can be found in the appendix.

Use this to size the cooling load! Northern Air Conditioning Orange County NY
 * Free online HVAC heat load calculator

Redundancy issues
Your air conditioner will fail. It is only a matter of when and whether you have one to back it up.

Emergency Fan ventilation
Can you ventilate into the building or the outside? What is the outside summer temperature?

Multiple air conditioners
Spare

Over-sized

Mov-n-cools

Alarm fail over

Thermostatic fail over

Differential temperature settings

Layout your air conditioners to minimize temperature variation across the room.

Humidity Control
Found in larger systems

Eliminates static problems

Requires addition of plumbing

Hot Aisles and Cold Aisles
Data centers are often separated into hot aisles and cold aisles. The back of the racks or cabinets face the hot aisle, because the hot air is blown in that direction. The fronts of 2 rows of cabinets face each other, and cold air is blown into this aisle to be forced through the front of the servers and out the back into the hot aisles.

Return air ducts are above the hot aisles, while cold air is blown up from underneath the floor into the cold aisle and sometimes into the front of the server cabinets.