Selecting high-efficiency centrifugal chillers: A system approach

This discusses balancing first cost and operating costs when choosing a chiller. For the past seven years, the HVAC/R industry has been trying to transition away from CFCs by increasing usage of HCFCs, HFCs, lithium bromide and water, ammonia, and other non-CFC refrigerants. However, as of January 1, 1996, more than 82 percent of the estimated 84,000 large centrifugal chillers in the US still use CFCs. Engineers today can specify chillers that are significantly more efficient than chillers produced even five years ago. Performance as low as 0.50 kw per ton at full load (ARI conditions) is not unusual today, and integrated part-load values (IPLV) as low as 0.41 can be achieved. Even lower values can be achieved at different design conditions. However, simply specifying a maximum value for peak-load performance or for the IPLV may overlook significant opportunities for operating cost savings over the life of the chiller.