ASME Code Standards for Pressure Vessels and Piping Engineering Practice Test 2026 - Free ASME Practice Questions and Study Guide

Total heat rejection is the sum of the cooling effect removed from the space and the heat added by the compressor. One ton of refrigeration (TR) equals 12,000 BTU/hr of cooling. The compressor’s power input becomes heat that is also rejected to the surroundings, and W = Qc / COP. With a typical COP around 4, the compressor adds about 3,000 BTU/hr for each 12,000 BTU/hr of cooling. So the total heat rejected is 12,000 + 3,000 = 15,000 BTU/hr, i.e., 1.25 times the cooling capacity. Hence, the total heat rejection is approximately TR multiplied by 1.25.