PURPOSE: To prevent moisture-rich cool air from circulating in a room by a structure wherein a carrying pipe of heat transfer medium such as brine or the line is connected in a loop so that the cryogenic heat produced at a heat source side heat exchanger by the evaporation of water is discharged at an availing side heat exchanger in the air conditioner directly utilizing the heat of vaporization of water.

CONSTITUTION: The heat source side heat exchanger 1 and the availing side heat exchanger 2 are respectively arranged at the upper and lower parts of the air conditioner. Groups of a large number of parallel plate fins 5 and 6 are respectively arranged between end plates 3 and 4. Pipes 7 and 8, which are connected to each other so as to make a loop and within which brine is forcibly circulated, are arranged in zigzags in such a manner that the pipes 7 and 8 respectively pierce the end plates 3 and 4 and the groups of fins 5 and 6 at right angles. In addition, a water sprinkling pan 12 is seated through a water-moistened cloth 13 onto the upper part of the group of plate fins 5 and a water collecting pan 14 is connected through a pump 18 to a water tank 15 by means of a return pipe 19 in order to send back the water dropped down from the water sprinkling pan 12 into the water collecting pan 14. Owing to the structure as described above, the surfaces of the fins of the heat source side heat exchanger is wetted at all times with the water circulated as just mentioned above, which is forcibly evaporated by means of a fan 10 in order to cool the plate fins 5. On the other hand, because the cool air cooled at the heat exchanger 2 is forcibly ventilated by means of a fan 11, the agreeable conditioning in the room can be realized.