Chiller

<p>A chiller uses a vapour-compression or absorption refrigeration cycle to extract heat from water, producing chilled water (typically 6–12°C supply) that is pumped to computer room air handlers (CRAHs) or coolant distribution units (CDUs). Heat is rejected to the atmosphere via a cooling tower or dry cooler connected to a condenser water loop.</p><p>Chillers are the primary cooling machinery in large facilities. Their efficiency is measured by COP and kW/TR (kilowatts per ton of refrigeration). Modern high-efficiency chillers achieve COP of 6 or higher at full load in favourable conditions. Variable-speed compressors improve part-load efficiency significantly. Chiller plant design — including staging, sequencing and integration with economisers — is a major determinant of a facility's PUE.</p>