METHOD OF OPERATING A HEAT PUMP LAUNDRY DRYER AND HEAT PUMP LAUNDRY DRYER OR HEAT PUMP WASHING MACHINE HAVING DRYING FUNCTION

The invention relates to a method of operating a heat pump laundry dryer or a heat pump washing machine having drying function and to such a laundry dryer or washing machine, wherein the laundry dryer or washing machine comprises: a control unit (30) controlling the operation of the laundry dryer or washing machine, a laundry treatment chamber (18) for treating laundry using process air, a process air circuit for circulating the process air, a heat pump system (4) having a refrigerant loop, in which the refrigerant fluid is circulated through a first and a second heat exchanger (10, 12), a compressor (14) for circulating the refrigerant fluid through the refrigerant loop, and a cooling fan unit (24) for cooling the compressor (14), and wherein the method comprises: detecting or monitoring one or a plurality of input variables during a running program cycle, determining the end of a program sub-sequence by detecting or monitoring the one or the plurality of input variables, modifying or changing an operation parameter set for operating the cooling fan unit upon determining the end of the program sub-sequence.