Abstract: Air conditioning and ventilating system including air conditioner installed on a ceiling, having air outlets for discharging air having heat heat exchanged at an indoor heat exchanger, and a device for controlling a direction of air discharged from the air outlets, a first air passage for guiding outdoor air to a room, and a second air passage for guiding room air to an outdoor. The first, and second air passages cross at a part, where a regenerative heat exchanger is provided. The deflecting plate is tilted at an angle from a ceiling surface for directing the air from the air outlet, not vertical to the ceiling surface, but at an angle from the ceiling surface.

Abstract: There is provided an air conditioning system and method for operating an air conditioner according to a user's physical response to external conditions. The air conditioning system includes: an indoor environment sensing unit/a personal characteristic value reception unit for measuring an indoor environment and the user's physical status so as to obtain information used to operate an air conditioner; a control unit including at least a microprocessor, for finding out personal characteristic values which are used to evaluate the user's physical status on the basis of information inputted from the personal characteristic value reception unit; and a driving unit controlled by the control unit, for promptly enhancing the user's physical status.