Centrifugal chillers are used in medium- and large-sized buildings to provide comfort cooling. Many of them use the vapor compression refrigeration cycle, including centrifugal compressors and plate-and-frame or shell-and-tube heat exchangers, to produce chilled water that can be pumped to AHUs and FHUs located in different spaces. At each AHU or FCU, the chilled water passes through a cooling coil while a fan blows air over the coil to produce cool air for the enclosed space. The chilled water then returns to the chiller unit, where it is re-cooled, and the process is repeated. Like other building systems, chiller systems require regular monitoring and maintenance in order to maintain their capacity and efficiency and avoid costly breakdowns and repairs. This course introduces common chiller types and components, including their purpose and design. Special attention is given to the compressor, which increases the pressure of the refrigerant and prepares it to reject heat in the condenser. It also identifies those items that should be regularly checked for leaks or wear and replaced periodically.
