PURPOSE: To obtain superior comfortableness and economy in heating operation by selectively allowing refrigerant to flow to an indoor heat exchanger when temperatures of a floor and air are not higher than respective set temperatures, and allowing the refrigerant to flow in such a manner as to raise temperature of either of the floor or the air which has a greater difference between the temperature detected by sensor and the set temperature than the other when the temperatures of the two have approached the respective set temperatures.

CONSTITUTION: In heating operation, when floor and air temperatures detected by floor and room temperature sensors 201, 203 are not higher than respective set temperatures, a mechanical valve 33 is closed and an indoor mechanical valve 25 is opened to allow refrigerant to selectively flow to an indoor heat exchanger 21. And when the floor and air temperatures have approached the respective set temperatures, either of those which has greater difference between detected temperature and the set temperature, specifically, if the difference between the air temperature and the set air temperature is greater than that of the floor, the mechanical valve 33 is closed and the indoor mechanical valve 25a is opened. If the difference between the floor temperature and the set floor temperature is greater than that of the air, the indoor mechanical valve 25a is closed and the mechanical valve 33 is opened, and a circulation pump 303 is operated to circulate water, which has been subjected to heat exchange in a heat exchanger 301, to a warm water circuit 305 laid within a floor 103.