The Basics of CRAC Units
Computer room air conditioning in the olden days utilized shared air conditioning units – similar to what you have in your household or work. These legacy units worked adequately but there were environmental gaps in the climate in the computer rooms.As an example, in colder months the humidity levels in the computer rooms typically dropped and high levels of static electricity began to form.
In recent times, CRAC units have become the main stay in big system computer rooms. These modern air monitoring and control systems provide active HVAC quality management. Modern CRAC systems are a combination of 3 systems; air conditioner, heating unit and humidifier. All three systems work together to continue the air quality within the computer room is maintained at adequate mixtures as per the setting stated by the data center personnel. These devices also provide online alerting and monitoring. for example if trouble conditions exist, these systems are intelligent enough to communicate with the data center manager / network operations team and alert them of such conditions.
Computer Room Air Conditioners (CRAC) in modern data centers, typically force conditioned air into a raised floor cavity. The raised floor is pressurized with the air quantity emitted by these units and is vented out into the data center room via perforated floor tiles. This kind of air management is very efficient and allows the data center manager to adequately vent the conditioned air in the correct areas of the data center ecosystem.
To ensure adequate levels of air conditioning and systems redundancy, many data centers at present utilize several CRAC units functioning either in tandem or in similar configurations. One case is to condition abundant cooling quantity to acceptably cool the server infrastructure within the determined area and the other reason is to provide levels of redundancy in the event one of the CRAC units were to fail. Essentially data centers over compensate cooling accommodation to ensure the cooling infrastructure exceeds current requirements and ensures true levels of HVAC redundancy.
CRAC units have also evolved into in-row cooling units which are being seen more and more in the data center ecosystem. In-row CRAC units are smaller than the traditional units, typically the dimensions of a cabinet server rack and are placed in-row within amongst computer server racks to provide in-row cooling to the server infrastructure. These units provide localized cooling and are more popular in niche based applications.
As with all fundamentals of technology, computer room cooling technology will continue to evolve over time as more intelligence will be outfitted within these intelligent cooling systems.