CONTROL OF DEFROST IN HEAT PUMP

摘要

A defrost control for a heat pump system initiates a defrost of the outdoor coil when certain computed conditions occur. The conditions include exceeding a limit as to the difference that may be permitted between the maximum indoor coil temperature occurring since the last defrosting of the outdoor coil and the current indoor coil temperature. The limit that may not be exceeded is computed as a function of the maximum indoor coil temperature occurring since the last defrosting of the outdoor coil.