The York YD model C dualcompressor centrifugal chillers from Johnson Controls are now available with Optispeed variable-speed drives and an
expanded capacity range of 1,500 to 6,000 tons. YD chillers with Optispeed VSD perform reliably, both in low- and medium-voltage applications that include district cooling, hospitals and higher education facilities, according to the manufacturer. YD chillers use two York centrifugal compressors
operating in parallel on a common set of heat exchanger shells to obtain large chiller capacities and effi cient part load operation. Off ering a high cooling capacity per footprint, the chillers are suitable for retrofit applications, where large amounts of cooling are required in a small space.