Computer Room Air Conditioner Units
Computer Room Air Conditioner Units are essential inside data centers where cooling is necessary for all the computer and electrical equipment most data centers utilize. It is important to keep the equipment cool to prevent overheating for some equipment. Removing the heat is the job of CRAC units in some cases and in other cases large Data centers use large air handlers to remove the heat however CRAC Units are the commonly used HVAC equipment used in most data centers for cooling data center equipment such as computers and electrical equipment. In a typical data center heat loads include servers, ups systems, power distribution units, static and automatic transfer switches, switchgear and other electrical equipment that produces heat during normal operation.
Computer Room Air Conditioner Units - Types
Some Computer Room Air Conditioners (CRAC Units) are DX with their own refrigeration systems built in while others rely on a chilled water system to provide chilled water to a coil in the CRAC unit. Most CRAC Units that are DX systems typically are used in smaller applications like branch offices and smaller types of data center set up where there is only one or a few servers to keep cool. The systems that use chilled water typically have intensive infrastructure and redundant systems for back up in case of failure of one or more systems. The chilled water CRAC systems also usually serve several servers/computers in a giant room. These systems usually do not use duct work but rather underfloor plenums that have specially perforated tiles to discharge air in selected areas within the data center where high heat loads are expected.
Computer Room Air Conditioner Units - Components
Inside most CRAC systems are a coil and a variable speed blower fan along with some controls. Many modern CRAC systems have solid sate controls and in data center set ups are integrated with either DDC controls or PLC controls for remote monitoring and control. Maintenance for CRAC units include changing the air filters, changing the belts (if not direct drive), and making sure the condensate drain pans are clear and can properly drain.
An additional resource for Computer Room Air Conditioners can be found here.