Computer Room Air Conditioning

A Computer Room Air Conditioning (CRAC) unit uses its own direct-expansion (DX) refrigeration circuit — with an internal compressor — to cool and dehumidify data hall air. Unlike a CRAH, a CRAC is self-contained and does not depend on a central chilled-water plant. CRAC units are common in smaller or older facilities; they have lower efficiency than chilled-water CRAH systems at scale but offer simpler installation and resilience without a central chiller.