Which one of the following is a device that uses circulating chilled water to remove heat?

A Computer Room Air Handling (CRAH) unit is a device that removes heat from a data center by using a simple heat exchange process. It contains a cooling coil and a fan. Warm air from the data center is drawn in by the fan and passed over the cooling coil, which is supplied with chilled water from a central chiller plant. The heat transfers from the air to the water. The now-cooled air is returned to the data center, and the warmed water is circulated back to the chiller to be cooled again.

B. "Computer Room Air System Unit" is not a standard industry acronym or a recognized type of cooling equipment.
C. "Air Suspension" is a term used in automotive engineering for vehicle suspension systems, not data center cooling.
D. "Air Suppression" refers to fire suppression systems that use inert gases or other agents to extinguish fires, not for cooling.

1. U.S. Department of Energy, Federal Energy Management Program (FEMP). (2016). Best Practices Guide for Energy-Efficient Data Center Design. Page 15, Section "Cooling System". The document states, "Chilled-water systems use Computer Room Air Handlers (CRAHs) that are similar to CRACs but do not have compressors. Instead, they use chilled water that is piped to them from a central chiller plant."

2. ASHRAE. (2021). Thermal Guidelines for Data Processing Environments, Fifth Edition. ASHRAE Datacom Series. Section 5.3.2, "Chilled-Water Air Handlers (CRAH)". This section details the operation of CRAH units, specifying their use of chilled water flowing through a cooling coil for heat removal.

3. Lawrence Berkeley National Laboratory (LBNL). (2012). Data Center Chilled Water System Optimization. LBNL-5873E. Page 2. The document defines the components of a typical data center cooling system, explaining that "The CRAH units are the final link in the cooling chain, transferring heat from the data center air to the chilled water loop."