Abstract: An apparatus for controlling air-exchange and pressure conditions in an air-conditioned room by opening and closing ducts and operating fans. The apparatus provides required indoor air pressure, such as a positive pressure for preventing dust from entering a room, or a cyclically modulated pressure in specific modes for achieving special atmospheric effects, such as to improve the spirits of occupants or to expel insects. The rate of change of the indoor pressure relative to the outdoor pressure can be measured in order to detect the degree of airtightness of the room. A warning signal is triggered when an abnormal condition of airtightness occurs, so that users may take steps to minimize unnecessary air-exchange, reduce energy consumption, and increase efficiency for air filtering and air conditioning.

Abstract: An air conditioning apparatus having a condenser fan, an evaporator fan, a compressor, at least two motor for driving the fans and the compressor, and being responsive to vibration of the apparatus to control the speed of each motor to reduce the vibration. In its preferred embodiments, the apparatus performs a test to determine optimum speeds of the motors to minimize the vibration. The apparatus uses a microcomputer, operative during the test to change the speed of at least one of the motors to each of a plurality of different speed values within a predetermined speed range, and at least one vibration detector. The detector detects values of the vibration when the motors are operating at the different speed values. At the end of the test, the motors are controlled to operate at the speed value at which the vibration is minimized.

Abstract: An axial-flow fan-blade, with at least one profiled guide fin extending from the surface of each blade of the fan-blade, is able to control flow direction of the fluid and keep fluid flow speed stable; and, furthermore, offsets the centrifugal force (which is caused by rotation of the blade) with the centripetal force that is generated by pressure difference of the fluid flowing across both sides of each profiled guide fin. The fan blade minimizes turbulent flow, reduces noise generated by vibration of the blades, and increases rigidity of the blades.

Abstract: A ventilation device, which comprises a sensor unit, a fan and control units to control on/off operation and the strength, temperature, humidity and directions of the wind or discharged air. The device can be applied to air conditioners, and ventilators. The sensor unit, monitoring the location and existence of human bodies within the ventilating area, enables the fan and the control units to be on or off while sensing the first person who comes into the area or the last person who leaves the area; and to adjust the strength and directions of the wind based on the location of the human bodies. The sensor unit, furthermore, can follow a specific human body and actuate the control units to provide needed wind based on his/her requirement. When the fan stops operating, all the openings of the ventilation device will shut so that the dust cannot get into the ventilation device.

Abstract: An oxygen generator accompanied with an air conditioner comprises a reservoir for collecting condensed water outside the evaporator, an electrolyzer for electrolizing the water from the reservoir to produce oxygen, and a controller for controlling the operation of the electrolyzer and providing suitable amount of oxygen into the room.

Abstract: A heat-pump type cooling system is disclosed which can provide cooling immediately before the compressor begins to rotate. The system stores liquid refrigerant condensed from compressed high pressure vapor in a liquid container, and releases it, through a control valve, to an evaporator and a temporary vapor receiver, enabling the cooling power to be controlled independently of the rotation of the compressor, in accordance with the operation of the control valve and the evaporator.