A drying machine according to the present invention includes an interface unit connected to a separate washing machine with a data communication line for receiving load information from the washing machine, a rotatable drum containing a load of wet clothes which are previously washed by the washing machine, and an air supply system coupled to the drum for supplying dry air into the drum. The machine further includes a heater coupled to the air supply system for heating the dry air, and a dryer controller generating a control signal to the heater in accordance with a set of operation values which are determined based on the load information. A method of operating a drying machine according to the present invention includes the steps of receiving load information from a separate washing machine that performs wash/dehydration cycles on a load of clothes, determining a set of optimal operation values for operating a heater on the basis of the load information where the heater heats the dry air being supplied into a drum containing the load of wet clothes, and generating a control signal to the heater in accordance with the determined optional values.