Abstract: A simultaneous heating/cooling multi air conditioner capable of performing heating and cooling simultaneously is provided. The simultaneous heating/cooling multi air conditioner includes a plurality of outdoor heat exchangers. The plurality of outdoor heat exchangers are configured to individually operate as a condenser or an evaporator depending on a heating/cooling ratio. Thus, even if the heating/cooling ratio changes, deterioration of the heating/cooling performance is prevented. When an operation mode is changed, continuous heating/cooling can be performed without stopping the system.

Abstract: A heat pump air conditioner includes an outdoor unit for heating use only for supplementing heating capacity when additional heating capacity must be provided to the heating capacity of an outdoor unit for heating and cooling in a heating mode. Since the outdoor unit for heating use only is installed independent from the outdoor units for heating and cooling use, such that the outdoor unit for heating use only can supplement the heating capacity only when the additional heating capacity is required in addition to the heating capacity of the outdoor units for heating and cooling use in the heating mode, in order to correspond to the heating load in cold climes, there is no need to install an outdoor unit having larger heating capacity than the required heating capacity. Thus, costs for installation and management are reduced.

Abstract: A multi-unit air conditioner and a method for controlling the same are disclosed which are capable of preventing continuous introduction of a refrigerant into indoor units in an OFF state where the indoor units can be independently powered on or off, thereby preventing a degradation in the cooling and heating efficiencies. The air conditioner includes a plurality of indoor units each including a power controller adapted to independently power on or off an associated one of the indoor units, an outdoor unit connected with the indoor units, the outdoor unit including a microcomputer for controlling an operation of the outdoor unit, and enabling the outdoor unit to communicate with the indoor units, and a controller for determining whether each of the indoor units is in a normal operation state or in a non-operation state, and controlling an operation of a distributor in accordance with the result of the determination.

Abstract: Disclosed herein are a multi-air conditioner and a group-unit control method thereof, wherein a plurality of indoor units can be controlled on a group basis. The method comprises the step of grouping the indoor units into a plurality of groups, the step of if an air conditioning operation condition of a specific one of the indoor units is changed, sending, by the specific indoor unit, the changed operation condition to all the other indoor units according to a predefined communication protocol, and the step of by each of the indoor units, receiving an air conditioning operation condition sent from a different one of the indoor units in the same group and performing an air conditioning operation based on the received operation condition. According to the invention, the plurality of indoor units can be more efficiently controlled on a group basis through inter-indoor unit data communication. Further, the group-unit control is not restricted by whether a controller is used or not.

Abstract: A method for controlling a multi-unit air conditioning system adapted to cool or heat room spaces while passing a refrigerant in one direction or in a reverse direction is disclosed. In the method, which is applied to a multi-unit air conditioning system including at least three compressors, when a compressor re-operation is repeatedly carried out after all of the compressors have been turned off, to turn on again at least one of the compressors, repetition of the compressor re-operation is carried out for a predetermined number of different orders in such a manner that at least one of the compressors is turned on first in an associated order of the repeated compressor re-operation.

Abstract: A refrigerant bypassing and filtering apparatus of an air conditioner is disclosed which is capable of effectively removing foreign matter such as slag produced in a refrigerant line, not only when the air conditioner is initially operated, but also during normal operation of the air conditioner. The apparatus includes at least one bypass line adapted to guide a refrigerant to bypass a main line through which the refrigerant flows between an outdoor unit and an indoor unit, a strainer arranged at the bypass line, a first valve arranged at the main line between opposite ends of the bypass line connected to the main line, and second valves arranged at the bypass line.

Abstract: An indoor unit of an air conditioner is disclosed. The air conditioner is an apparatus that cools or heats an indoor space by circulating refrigerant in one direction or another. The indoor unit of the air conditioner comprises a case spaced apart from the ceiling of a room by a predetermined distance, an indoor heat exchanger provided in the case to heat or cool the room, and a fan and fan motor provided in the case to suction and discharge air.

Abstract: Disclosed herein is a control method for a multiple heat pump. In the control method, when one of multiple indoor units operates in the heating mode and the other indoor units shut down, electronic expansion valves of the shutdown indoor units are controlled to have an opening degree higher than a standard opening degree if an outlet temperature of compressors is higher than a preset temperature, so as to permit a liquid refrigerant, remaining in the shutdown indoor units, to be more readily recovered to the compressors. This eliminates a refrigerant shortage phenomenon of the compressors and prevents deterioration of heating performance as well as reduction of life-span of the compressors.

Abstract: Disclosed herein is a control method for four-way valves of a multiple heat pump. In the control method, if even at least one of four-way valves of respective outdoor units is not switched to a desired mode upon switching of all of the four-way valves to the desired mode, the other four-way valves, switched to the desired mode, is switched to an opposite direction of the desired mode, and then all of the four-way valves are switched again to the desired mode, thereby simply and rapidly correcting switching error of the four-way valves, resulting in normal operation of the multiple heat pump.

Abstract: Disclosed is an apparatus and method for preventing liquid refrigerant accumulation in an accumulator of an outdoor unit of an air conditioner. The method includes the steps of: determining a state of a compressor; if the compressor is in standby mode or off state, turning on a four-way valve; determining whether the state of the compressor in standby mode or off state continues longer than a predetermined amount of time; and if the state of the compressor continues longer than the predetermined amount of time, closing an expansion valve. Particularly, high-pressure refrigerant flows in the closed expansion valve while low-pressure refrigerant flows in a check valve through the four-way valve.

Abstract: A system for controlling an air conditioner includes a plurality of outdoor units each having at least one compressor and an outdoor heat exchanger, an indoor unit connected to the outdoor units by a refrigerant tube, the indoor unit having an indoor heat exchanger, and a pressure regulating tube for equalizing pressure according to an operation mode. The pressure regulating tube is connected between the outdoor units.

Abstract: Provided is an air conditioner, particularly, an apparatus and method for controlling a super-heating degree in a heat pump system for preventing a liquid refrigerant from flowing into a compressor. The method includes: operating the heat pump system; receiving a present outdoor temperature, a pipe absorption temperature and a low pressure value of a compressor, respectively; computing a present absorption super-heating degree from a difference between the absorption temperature of the compressor and a saturated temperature at a low pressure side; and comparing an targeted absorption super-heating degree set in advance, with the computed present absorption super-heating degree according to the received outdoor temperature, and controlling the system so that the present absorption super-heating degree may follow the targeted absorption super-heating degree.