Computer Room Air Conditioning Units (CRACs)

Silent-Aire CRAC units have been deployed in some of the most sophisticated data center facilities around the globe

Computer Room Air Conditioner (CRAC) and Computer Room Air Handling Unit (CRAHU)

Silent-Aire CRAC/CRAH units have been deployed in some of the most sophisticated data center facilities around the globe. Our capabilities in designing, engineering and manufacturing innovative solutions have earned us the trust of leading edge data center owners and operators for over a decade.

General Features and Uses

Silent-Aire CRAC/CRAH Units are used to manage the environments of data centers owned by wholesalers, co-location providers and cloud service providers as well as major corporations.Our CRAC/CRAH units feature;

  • Heavy Duty Construction
  • Energy Efficient Cooling
  • Customizable to site specific needs
  • System Redundancy/Reliability
  • Ease of maintenance
  • Fully packaged for ease of installation
  • Single point electrical and water connection
  • Variable Speed Operation

Construction Details and Cooling options

As a custom manufacturer Silent-Aire Systems is capable of producing CRAC units as specified by our clients. Our standard construction features the following;

  • 18 gauge steel outercasing with satin finish (heavier gauges are available)
  • High Efficiency MERV13 Filters
  • Doors with gas shock supports for ease of maintenance
  • High quality door hardware
  • Full on-board controls
  • Compact high efficiency air foil plenum fans on VFD
  • Evaporative pad thickness b/w 4 and 12 inches available.

Cooling Options

Silent-Aire Systems is able to provide our clients with a variety of cooling options including

Free Cooling

Free cooling CRAC control systems analyze the outdoor air conditions and will use outdoor air when outside temp and humidity conditions permit. When free cooling is engaged all other cooling is turned off; only unit fans are active. Most geographic locations’ climate conditions permit the use of free cooling during most off-peak temperature and humidity conditions to maximize energy efficiency.

Chilled Water

In using a chilled water option, air is cooled by passing through a chilled water coil within the CRAC unit that utilizes the Data Center owners central chilled water plant. This allows for full recirculation of data center air during peak outdoor humidity and temperature air conditions where evaporative air cooling is not possible. This usually occurs during peak temperature hours during the summer. Water pressure drop through Silent-Aire CRAC units is typically/roughly is half that of an equivalent off the shelf CRAC unit.

Direct Expansion (DX) Cooling

(DX) cooling is a traditional mechanical refrigerant based cooling system that is available in air cooled and water cooled systems. The water cooled systems tie into owners chilled water system. Air cooled systems utilize outdoor condensing units and are ideal when central chilled water system is unavailable. Available in a wide range of environmentally friendly HFC based refrigerants

Direct / Indirect Evaporative Cooling

Silent-Aire is the only manufacturer to incorporate direct / indirect evaporative cooling in CRAC units. In using Direct evaporative cooling, air is cooled by evaporation of water in the airstream without the need for compressorized refrigerant-based systems. Evaporative cooling requires up to 95% less energy than what is associated with traditional cooling systems. It is most effective when high temperature and low-medium humidity outdoor conditions exist. In dry climate conditions are such that entire peak design cooling load can be handled entirely by direct evaporative cooling without the need for additional mechanical cooling.

Non-Tradtional Cooling Methods

As a custom manufacturer of CRAC units Silent-Aire has the engineering and manufacturing capability to work with clients to implement non-traditional and novel cooling methods. Our in factory research and development allows for prototype testing and performance tuning.

Performance Data

Our CRAC / CRAH units are capable of cooling performance measures up to 260 tons for each mode of cooling. As a standard we achieve between 20,000 and 104,000 CFM. The CRAC / CRAH units are downflow as a standard, however, upflow and horizontal configurations are available. As a custom manufacturer we can accommodate other configurations and sizes.

Controls and Operating systems

Our control solution is based on pCO Sistema: the CAREL range of programmable logic controllers. This consists of programmable controllers, user interfaces, communication and remote management interfaces to offer HVAC/R market flexibility and easy integration with commonly-used building management systems. Supervisory communication protocols supported are: Modbus®, LonWorks®, BACnet™, and SNMP. Units can operate independently on their own control strategy or can be remotely operated by a supervisory system or master PLC. An optional Field-Bus communication port for control of RS485, CANbus, tLAN industrial devices can be added. Our control solutions can also be customized to flexibly adapt to a client’s control scheme. Further, we can implement a variety of interface terminals from alphanumerical monochrome to color HMI touchscreen. Our units can be built to any CEC, NEC or IEC electrical standards for various loads and power systems.

Commissioning and Maintenance

CRAC units are inherently low maintenance; designed for continuous worry-free operation. Most maintenance items are periodic component inspections and cleanings.

  • Inspect fans/motors for signs of wear or damage, dirt and corrosion every 3-4 months
  • Inspect foundation bolts, set screws and fasteners for tightness annually.
  • Clean coils every 2-3 months.
  • Clean evaporative cooler media and flush system every 4-6 weeks during operating season, inspect for signs of damage or wear.
  • Clean water filters weekly
  • Inspect filters regularly, replace when visibly dirty.