PRECISION COOLING

The specification, installation, and operation of IT environment cooling systems, are the most essential yet least understood of all critical IT environment processes. As the current and emerging IT hardware becomes smaller and uses the same or even more electricity than the equipment it replaced, more heat is being generated in data centers and server rooms. Precision cooling and heat rejection equipment is used to collect and transport this unwanted heat energy to the outside atmosphere.

Cassius Group provides consultation services which take away the headache of choosing the most suitable, energy and cost efficient solution for your space. The various system types and a brief description follows:

Air cooled systems (2-piece)

This type of system is often referred to as a DX system or split-type system. In an air cooled system half the components of the refrigeration cycle are in the computer room air conditioner (also known as a CRAC unit) and the rest are outdoors in the an cooled condenser.

Air cooled self-contained systems (1-piece)

Self-contained systems locate all the components of the refrigeration cycle in one enclosure that is usually found in the IT environment.

Glycol cooled systems

This type of system locates all refrigeration cycle components in one enclosure (like a self-contained system) but replaces the bulky condensing coil with a much smaller heat exchanger.

Water cooled systems

Water cooled systems are similar to glycol cooled systems in that all refrigeration cycle components are located inside the computer room air conditioner. However, there are two important differences between a glycol cooled system and a water cooled system:

·         A water (also called condenser water) loop is used instead of glycol to collect and transport heat away from the IT environment

·         Heat is rejected to the outside atmosphere via a cooling tower instead of a fluid cooler.

Chilled water systems

In a chilled water system the components of the refrigeration cycle are relocated from the computer room air conditioning systems to a device called a water chiller

Other Elements of Precision Cooling Systems

Airflow direction

Large floor mounted systems flow air in a downward direction (down-flow) or an upward direction (up-flow) and some can even flow horizontally (horizontal flow).  

·         Down-flow systems are used in a raised floor environment or in a non-raised floor environment when system is mounted on a pedestal.

·         Up-flow systems are used in an existing up-flow environment

·         Horizontal flow systems should be considered for IT consolidations and IT environment renovations using a hot/cold aisle configuration.

Fire, Smoke, and Water Detection Devices

Provide early warning and/or automatic shut off during catastrophic events.

·         Use recommended in all units. Use mandatory if required by local building codes. Best used in conjunction with IT monitoring and building management systems for quickest notification.

Humidifiers

Are commonly located inside precision cooling devices to replace water vapor lost in the cooling process and are used to prevent IT equipment downtime due to static electrical discharge.

·         Humidifiers are used in all computer room air conditioners and air handlers unless the room has a properly functioning vapor barrier and central humidification system. The room must have no current high or low humidity-related problems.

Reheat Systems

Actually add heat to conditioned cold air exiting a precision cooling device to allow the system to provide increased dehumidification of IT environment air when it’s required.

·         Reheat systems are used for rooms in warm, humid climates or in rooms with poor or non-existent vapor barriers.