A heat pump laundry dryer or a heat pump washing machine having a drying function, includes a control unit controlling an operation of the laundry treatment apparatus. A laundry treatment chamber treats laundry using process air circulated in a process air circuit. A heat pump system has a refrigerant loop in which refrigerant fluid is circulated through a first and a second heat exchanger. A compressor circulates the refrigerant fluid through the refrigerant loop, and a cooling fan unit cools the compressor. During the operation, a conveyance capacity of the cooling fan unit is varied. A detector unit detects an operation parameter indicating a state of at least one electronic board. A method of operation includes operating the cooling fan unit based upon the electronic board operation parameter, and controlling the compressor operation output based upon the electronic board operation parameter, wherein the compressor is a variable speed compressor.