INDOOR APPARATUS IN AIR-CONDITIONING SYSTEM AND METHOD FOR CONTROLLING THE APPARATUS

The present disclosure relates to an indoor apparatus of an air-conditioning system with a reduced noise level and to a method for controlling the apparatus.The apparatus includes: a heat-exchanger (110) for exchanging heat between refrigerant and indoor air; a fan (130) rotating to flow air to the heat-exchanger; an expansion valve (150) for expanding refrigerant discharged from the heat-exchanger; a first temperature sensor (161) disposed on a first conduit for supplying refrigerant to the heat-exchanger, wherein the first temperature sensor detects a first temperature of refrigerant to be fed into the heat-exchanger; a second temperature sensor (163) disposed on a second conduit for receiving refrigerant from the heat-exchanger, wherein the second temperature sensor detects a second temperature of refrigerant discharged from the heat-exchanger; and a controller (170) configured to: calculate a suctioned refrigerant superheat based on a difference between the first and second temperatures; and to control activation or deactivation of the fan and/or opening or closing of the expansion valve based on the calculated suctioned refrigerant superheat to reduce a noise level of the indoor apparatus.