Abstract: An air conditioner of the present invention includes: an outdoor unit having an outdoor heat exchanger and a compressor installed therein; a plurality of indoor units connected to the outdoor unit and having an indoor heat exchanger installed therein; a four-way valve provided on a discharge part side of the compressor; a refrigerant tube having first to third refrigerant tubes and connecting the four-way valve and the indoor heat exchanger, in which the first refrigerant tube is branched from between the four-way valve and the outdoor heat exchanger such that some of a refrigerant discharged from the compressor is fed into the indoor heat exchanger while bypassing the outdoor heat exchanger, the second refrigerant tube is connected to the four-way valve to feed all of the refrigerant discharged from the compressor into the indoor heat exchanger, and the third refrigerant tube is connected to the second refrigerant tube in parallel; and a heat pump valve provided at the third refrigerant tube to selectively c

Abstract: An air conditioner that improves efficiency of an inverter compressor by injecting an intermediate pressure refrigerant to the inverter compressor during heating or cooling and a control method thereof are provided.

Abstract: A cooling and heating control method of a multi type air conditioner in which a target pressure of a compressor is adjusted based on conditions of respective indoor units so as to reduce power consumption is provided. The cooling control method includes determining the indoor unit desired to execute power saving control, judging whether or not a difference between a temperature of a space in which the indoor unit desired to execute power saving control is located and a set temperature of the indoor unit is less than a reference value, raising a target evaporation temperature of the indoor unit upon judging that the difference is less than the reference value, comparing an evaporation temperature of the indoor unit with the raised target evaporation temperature, and raising an evaporation pressure of a compressor, when the evaporation temperature of the indoor unit is lower than the raised target evaporation temperature.

Abstract: An air conditioner having a plurality of outdoor units and a plurality of indoor units with a common piping connected via a common piping to transfer refrigerant therebetween, the air conditioner including a first outdoor unit to provide heat, a second outdoor unit to defrost a heat exchanger of the second outdoor unit, and a first refrigerant guide unit in the second outdoor unit to guide a flowing direction of the refrigerant, wherein the refrigerant discharged from the first outdoor unit is circulated through the heat exchanger of the second outdoor unit.

Abstract: The object of this invention is to provide an air conditioner with a variable capacity compressor (2) parallely connected to a fixed capacity compressor (4), and a method of controlling the operation of such an air conditioner. When it is required to start the fixed capacity compressor (4) in addition to an operation of the variable capacity compressor (2) due to an increase in the sum of the required cooling capacities of indoor units (9), an outdoor control unit (13) starts the fixed capacity compressor (4) during an unloading mode operation of the variable capacity compressor (2) where the pressure difference between the outlet side and inlet side of the variable capacity compressor is minimized. The fixed capacity compressor (4) is thus smoothly started without causing an induction of excessive starting current, and improves the operational reliability of the air conditioner.

Abstract: An air conditioner having a plurality of outdoor units and a plurality of indoor units with a common piping connected via a common piping to transfer refrigerant therebetween, the air conditioner including a first outdoor unit to provide heat, a second outdoor unit to defrost a heat exchanger of the second outdoor unit, and a first refrigerant guide unit in the second outdoor unit to guide a flowing direction of the refrigerant, wherein the refrigerant discharged from the first outdoor unit is circulated through the heat exchanger of the second outdoor unit.

Abstract: Disclosed herein is a system and method for controlling the degree of superheat of an air conditioner. The air conditioner includes a compressor controlled in a pulse width modulation manner according to duty control signals, a condenser, an electronic expansion valve and an evaporator so as to form a refrigeration cycle. An entrance temperature sensor situated at the entrance of the evaporator and an exit temperature sensor situated at the exit of the evaporator are connected to a control unit. The control unit calculates the degree of superheat of the evaporator using the difference between mean entrance and exit temperatures of the evaporator sensed by the entrance temperature sensor and the exit temperature sensor for a period of time corresponding to a duty cycle period of the compressor, and regulates the opening of the electronic expansion valve according to the calculated degree of superheat.

Abstract: An air conditioning apparatus and control method thereof includes an inverter-type compressor and a two-stage variable-capacity compressor connected in parallel with their respective capacities controlled according to indoor air conditioning loads. Thus, the present invention is cost-competitive due to a capacity of the inverter-type compressor being lower than that of the two-stage variable-capacity compressor.

Abstract: An air conditioning apparatus and control method thereof is provided, in which a pulse width modulation compressor and a two-stage variable-capacity compressor are connected in parallel with each other to control capacities of the two compressors according to indoor air conditioning loads. The air conditioning apparatus is cost-competitive because a capacity supplied by the pulse width modulation compressor is relatively low in cost, and the cost required for manufacturing the compressor is reduced in proportion to the reduced capacity. Accordingly, with the air-conditioning apparatus an effect is obtainable in which a variable-capacity compressor with small capacity and a two-stage variable-capacity compressor with large capacity are controlled as if a large-scale variable-capacity compressor with a same capacity as a total capacity of the two compressors were linearly controlled.

Abstract: The object of this invention is to provide an air conditioner with a variable capacity compressor (2) parallely connected to a fixed capacity compressor (4), and a method of controlling the operation of such an air conditioner. When it is required to start the fixed capacity compressor (4) in addition to an operation of the variable capacity compressor (2) due to an increase in the sum of the required cooling capacities of indoor units (9), an outdoor control unit (13) starts the fixed capacity compressor (4) during an unloading mode operation of the variable capacity compressor (2) where the pressure difference between the outlet side and inlet side of the variable capacity compressor is minimized. The fixed capacity compressor (4) is thus smoothly started without causing an induction of excessive starting current, and improves the operational reliability of the air conditioner.

Abstract: An air conditioning apparatus and control method thereof is provided, in which two-stage variable-capacity compressors are connected in parallel with each other to control capacities of the two stage variable-capacity compressors according to indoor air conditioning loads. A pair of two-stage variable-capacity compressors are used in the air conditioning apparatus to be cost competitive and can obtain an effect in which the pair of two-stage variable-capacity compressors are controlled as if a large-scale variable-capacity compressor with a capacity the same as a total capacity of the two compressors were linearly controlled.

Abstract: An outdoor unit includes a pulse width modulation compressor, an outdoor heat exchanger. First and second outdoor fans are positioned near to the outdoor heat exchanger. The operation modes of the first and second outdoor fans are determined in accordance with the amount of refrigerant discharged from the compressor and external conditions. An outdoor temperature sensor is electrically connected to the input port of the outdoor control unit, and first and second outdoor fan operating units for respectively operating first and second outdoor fans are connected to the output port of the outdoor control unit. The outdoor control unit operates the first and second fans in a preset operation mode by confirming outdoor temperature data input from the outdoor temperature sensor and the loading time of the compressor and controlling the first and second outdoor fan operating units.

Abstract: An air conditioning apparatus and control method thereof is provided, in which two-stage variable-capacity compressors are connected in parallel with each other to control capacities of the two stage variable-capacity compressors according to indoor air conditioning loads. A pair of two-stage variable-capacity compressors are used in the air conditioning apparatus to be cost competitive and can obtain an effect in which the pair of two-stage variable-capacity compressors are controlled as if a large-scale variable-capacity compressor with a capacity the same as a total capacity of the two compressors were linearly controlled.

Abstract: An air conditioning apparatus and control method thereof is provided, in which a pulse width modulation compressor and a two-stage variable-capacity compressor are connected in parallel with each other to control capacities of the two compressors according to indoor air conditioning loads. The air conditioning apparatus is cost-competitive because a capacity supplied by the pulse width modulation compressor is relatively low in cost, and the cost required for manufacturing the compressor is reduced in proportion to the reduced capacity. Accordingly, with the air-conditioning apparatus an effect is obtainable in which a variable-capacity compressor with small capacity and a two-stage variable-capacity compressor with large capacity are controlled as if a large-scale variable-capacity compressor with a same capacity as a total capacity of the two compressors were linearly controlled.

Abstract: An air conditioning apparatus and control method thereof includes an inverter-type compressor and a two-stage variable-capacity compressor connected in parallel with their respective capacities controlled according to indoor air conditioning loads. Thus, the present invention is cost-competitive due to a capacity of the inverter-type compressor being lower than that of the two-stage variable-capacity compressor.

Abstract: A system for controlling the starting of an air conditioner includes a compressor controlled in a pulse width modulation according to a duty cycle control signal, an electronic expansion valve for expanding refrigerant compressed in the compressor, a high pressure conduit connecting the exit side of the compressor and the inlet side of the electronic expansion valve, a low pressure conduit connecting the exit side of the electronic expansion valve and the inlet side of the compressor, a bypass conduit connected at its first end to the high pressure conduit and at its second end to the low pressure conduit, and a flow rate regulating valve mounted on the bypass conduit for regulating a flow rate of fluid flowing through the bypass conduit. A control unit controls the compressor during the starting of the compressor in such a way that the electronic expansion valve is open, the flow rate regulating valve is open and a duty control signal shorter than a duty control signal during a normal operation is generated.

Abstract: An air conditioner control system comprises an outdoor unit having a compressor controlled by pulse-width modulation, and a plurality of indoor units. Each of the plurality indoor units has an indoor control unit to calculate a respective required individual cooling capacity, and an indoor communication circuit unit through which the required individual cooling capacity calculated is transmitted. The outdoor unit has an outdoor control unit producing a duty cycle control signal in response to the required individual cooling capacity transmitted from the indoor units to control the capacity of the compressor, and an outdoor communication circuit unit to communicate the indoor communication circuit unit of respective ones of the plurality of indoor units.

Abstract: An outdoor unit includes a pulse width modulation compressor, an outdoor heat exchanger. First and second outdoor fans are positioned near to the outdoor heat exchanger. The operation modes of the first and second outdoor fans are determined in accordance with the amount of refrigerant discharged from the compressor and external conditions. An outdoor temperature sensor is electrically connected to the input port of the outdoor control unit, and first and second outdoor fan operating units for respectively operating first and second outdoor fans are connected to the output port of the outdoor control unit. The outdoor control unit operates the first and second fans in a preset operation mode by confirming outdoor temperature data input from the outdoor temperature sensor and the loading time of the compressor and controlling the first and second outdoor fan operating units.

Abstract: A system for controlling the starting of an air conditioner includes a compressor controlled in a pulse width modulation according to a duty cycle control signal, an electronic expansion valve for expanding refrigerant compressed in the compressor, a high pressure conduit connecting the exit side of the compressor and the inlet side of the electronic expansion valve, a low pressure conduit connecting the exit side of the electronic expansion valve and the inlet side of the compressor, a bypass conduit connected at its first end to the high pressure conduit and at its second end to the low pressure conduit, and a flow rate regulating valve mounted on the bypass conduit for regulating a flow rate of fluid flowing through the bypass conduit. A control unit controls the compressor during the starting of the compressor in such a way that the electronic expansion valve is open, the flow rate regulating valve is open and a duty control signal shorter than a duty control signal during a normal operation is generated.

Abstract: Disclosed herein is a system and method for controlling the degree of superheat of an air conditioner. The air conditioner includes a compressor controlled in a pulse width modulation manner according to duty control signals, a condenser, an electronic expansion valve and an evaporator so as to form a refrigeration cycle. An entrance temperature sensor situated at the entrance of the evaporator and an exit temperature sensor situated at the exit of the evaporator are connected to a control unit. The control unit calculates the degree of superheat of the evaporator using the difference between mean entrance and exit temperatures of the evaporator sensed by the entrance temperature sensor and the exit temperature sensor for a period of time corresponding to a duty cycle period of the compressor, and regulates the opening of the electronic expansion valve according to the calculated degree of superheat.