To prevent the deterioration of indoor environment by a cold draft and to reduce indoor air mixing loss simultaneously by sucking air form an inlet hole, and diffusing the air after subjecting the air to conditioning and diffusing it from an outlet hole again.
In the heating of perimeter zone P, a first inlet hole 9 is opened and a second inlet hole 10 is closed so that the indoor air is taken into a casing 2 through the first inlet hole 9 and is blown upward from the outlet hole 8 as hot air. In winter, a cold draft C is generated along a window surface 102, descends along the window surface 102 and is taken into the first inlet hole 9 so that no cold draft vortex is generated at the upper surface of the casing 2 and no cold draft reaches a floor surface 103 or an interior zone I. Therefore, the temperature of the air on the window surface is warmed to near the room temperature and through heat load is treated effectively.
KOU TETSUO
ISHIZUKA KEIICHI
