Drying control apparatus and method of washing and drying machine

A drying control method of a washing and drying machine, which controls a circulation fan for causing air in a drum to sequentially pass through a tub, a condensation duct, and a heater duct and to be introduced again into the drum, a cooling water valve for supplying cooling water to the condensation duct so that moisture contained in the air passing through the condensation duct is condensed by the cooling water, and a heater for heating the air passing through the heater duct, wherein:

• ON/OFF conditions of the circulation fan, the cooling water valve, and the heater are determined according to the input of kind, drying time, and dryness of laundry to be dried, and
• when one mode out of a rapid drying mode, a power saving mode, and a water saving mode is inputted to the washing and drying machine, the ON/OFF condition of at least one of the circulation fan, the cooling water valve, and the heater is changed according to the inputted mode.

A drying control apparatus of a washing and drying machine, in which:

• when air drying laundry passes through a condensation duct after a drying operation for drying the laundry is started, a temperature of cooling water condensing moisture contained the air and a temperature of the air dehumidified by passing through the condensation duct are measured, and
• when the drying operation is continued, the dried state of the laundry is determined by a difference temperature between a signal representing characteristics of the temperature of the cooling water and a signal representing characteristics of the temperature of the air, so as to control the drying operation.