Abstract: An air conditioner is provided, in which some of a plurality of outdoor heat exchangers implement a defrosting operation and others implement a heating operation. The air conditioner includes a compressor to compress refrigerant, a hot gas pipe to which a part of the refrigerant compressed in the compressor is moved, a 4-way valve to which the remaining refrigerant compressed in the compressor is moved, an indoor heat exchanger in which the refrigerant, having passed through the 4-way valve, undergoes heat exchange with indoor air, and a plurality of outdoor heat exchangers, some of which implement a heating operation as the heat-exchanged refrigerant from the indoor heat exchanger is moved therethrough while others implement a defrosting operation as the refrigerant having passed through the hot gas pipe is moved therethrough.

Abstract: An air conditioner includes a compressor, a first heat exchanger, and a first pipe configured to allow refrigerant to flow from the first heat exchanger. A bypass pipe is branched off from the first pipe and is configured to expand refrigerant flowing through the bypass pipe. A second heat exchanger is configured to allow the expanded refrigerant of the bypass pipe to heat-exchange with the refrigerant flowing along the first pipe. A second pipe couples the second heat exchanger to the compressor so that the refrigerant expanded by the bypass pipe and heat-exchanged at the second heat exchanger can be introduced into the compressor.

Abstract: In a refrigerant amount determining method of an air-conditioning apparatus, when a refrigerant amount determining mode is requested to be performed, whether or not the amount of refrigerant in the air-conditioning apparatus can be automatically determined. Thus, a user can easily check whether or not the refrigerant charged in the air-conditioning apparatus is excessive or insufficient.

Abstract: An air conditioner includes a compressor, a first heat exchanger, and a first pipe configured to allow refrigerant to flow from the first heat exchanger. A bypass pipe is branched off from the first pipe and is configured to expand refrigerant flowing through the bypass pipe. A second heat exchanger is configured to allow the expanded refrigerant of the bypass pipe to heat-exchange with the refrigerant flowing along the first pipe. A second pipe couples the second heat exchanger to the compressor so that the refrigerant expanded by the bypass pipe and heat-exchanged at the second heat exchanger can be introduced into the compressor.

Abstract: An air conditioner includes a plurality of compressors, a common intake pipe, and a plurality of oil equalizing pipes that connect the compressors to the common intake pipe such that oil existing above a reference oil level in the compressors can be transferred to the common intake pipe. An oil equalizing valve provided on at least two of the oil equalizing pipes controls oil flowing through the oil equalizing pipes, where at least two of the oil equalizing valves can be opened together during performance of oil equalizing operation such that amounts of the oil in at least two compressors can be equalized.

Abstract: An air conditioner is provided, in which some of a plurality of outdoor heat exchangers implement a defrosting operation and others implement a heating operation. The air conditioner includes a compressor to compress refrigerant, a hot gas pipe to which a part of the refrigerant compressed in the compressor is moved, a 4-way valve to which the remaining refrigerant compressed in the compressor is moved, an indoor heat exchanger in which the refrigerant, having passed through the 4-way valve, undergoes heat exchange with indoor air, and a plurality of outdoor heat exchangers, some of which implement a heating operation as the heat-exchanged refrigerant from the indoor heat exchanger is moved therethrough while others implement a defrosting operation as the refrigerant having passed through the hot gas pipe is moved therethrough.

Abstract: An apparatus for controlling a refrigerant level comprises a first detecting unit installed at a lower side of the inside of a refrigerant tank, for detecting whether a refrigerant stored at a lower side of the inside of the refrigerant is a liquefied refrigerant or a gaseous refrigerant, a second detecting unit installed at an upper side of the inside of the refrigerant tank, for detecting whether a refrigerant stored at an upper side of the inside of the refrigerant tank is a liquefied refrigerant and a gaseous refrigerant, and a control unit controlling intake and discharge of the liquefied refrigerant according to a value measured by the first detecting unit and the second detecting unit.

Abstract: In a refrigerant amount determining method of an air-conditioning apparatus, when a refrigerant amount determining mode is requested to be performed, whether or not the amount of refrigerant in the air-conditioning apparatus can be automatically determined. Thus, a user can easily check whether or not the refrigerant charged in the air-conditioning apparatus is excessive or insufficient.

Abstract: An air-conditioner having a dual-refrigerant cycle includes a primary refrigerant circuit heat-exchanged with outdoor air; a secondary refrigerant circuit heat-exchanged with indoor air to perform either a cooling operation or a heating operation; and a heat exchange unit disposed between the primary refrigerant circuit and the secondary refrigerant circuit to perform heat exchange therebetween, wherein the secondary refrigerant circuit includes a compressor for compressing a refrigerant circulating in the secondary refrigerant circuit. A condensing pressure of the primary refrigerant circuit is lowered during the hating operation and an evaporation pressure of the primary refrigerant circuit is increased to thereby enhance efficiency of the air-conditioner.

Abstract: A second-refrigerant pump driving type air conditioner, including an indoor unit having an indoor heat exchanger that circulates a refrigerant containing no oil, a first circulator including a compressor that compresses and discharges a refrigerant containing oil, a first outdoor heat exchanger, a second outdoor heat exchanger, and an outdoor expander, and a second circulator including an intermediate heat exchanger connected to the indoor heat exchanger that circulates the refrigerant containing no oil and heat-exchanges the refrigerant of the first outdoor heat exchanger, a receiver, and a pump. A restriction of a length and a diameter of a connection pipe for connecting an outdoor unit and the indoor unit is decreased, and an oil shortage of the compressor is prevented.

Abstract: An air conditioning system comprises a first tank connected to an outlet side refrigerant line of an indoor unit, a second tank disposed to be lower than the first tank, middle tank installed between the first tank and the second tank, a heat source cycle for depressurizing and cooling the first refrigerant inside the first tank by circulating a second refrigerant and heating the first refrigerant of the second tank, a middle tank cooling unit for feed back connected to an inlet side refrigerant line of the second tank among refrigerant lines of the heat source cycle, a middle tank heating unit for feed back connected to a refrigerant line between the first tank and the second tank among refrigerant lines of the heat source cycle, and a controller for selectively circulating the second refrigerant of the heat source cycle to the middle tank cooling unit for feed back or the middle tank heating unit for feed back.

Abstract: A second-refrigerant pump driving type air conditioner, including an indoor unit having an indoor heat exchanger that circulates a refrigerant containing no oil, a first circulator including a compressor that compresses and discharges a refrigerant containing oil, a first outdoor heat exchanger, a second outdoor heat exchanger, and an outdoor expander, and a second circulator including an intermediate heat exchanger connected to the indoor heat exchanger that circulates the refrigerant containing no oil and heat-exchanges the refrigerant of the first outdoor heat exchanger, a receiver, and a pump. A restriction of a length and a diameter of a connection pipe for connecting an outdoor unit and the indoor unit is decreased, and an oil shortage of the compressor is prevented.

Abstract: An air conditioning system comprises an indoor unit in which a first refrigerant flows, a first tank connected to an outlet side refrigerant line of the indoor unit for sucking a first refrigerant, a second tank connected to an inlet side refrigerant line of the indoor unit and directly connected to the first tank at a position lower than the first tank for feeding back the first refrigerant stored in the first tank to the indoor unit, a connection line disposed between the first tank and the second tank, a pressure equalizing line disposed between the first tank and the second tank, a heat source cycle for cooling the first refrigerant inside the first tank by circulating a second refrigerant and heating the first refrigerant of the second tank, and a controller for controlling a plurality of switching valves installed at the connection line and the pressure equalizing line.

Abstract: An air conditioning system comprises a first tank connected to an outlet side refrigerant line of an indoor unit, a second tank disposed to be lower than the first tank, middle tank installed between the first tank and the second tank, a heat source cycle for depressurizing and cooling the first refrigerant inside the first tank by circulating a second refrigerant and heating the first refrigerant of the second tank, a middle tank cooling unit for feed back connected to an inlet side refrigerant line of the second tank among refrigerant lines of the heat source cycle, a middle tank heating unit for feed back connected to a refrigerant line between the first tank and the second tank among refrigerant lines of the heat source cycle, and a controller for selectively circulating the second refrigerant of the heat source cycle to the middle tank cooling unit for feed back or the middle tank heating unit for feed back.

Abstract: Disclosed is an air conditioner. The air conditioner includes: at least one indoor unit; an outdoor unit communicating with the indoor unit and having at least one compressor and one outdoor heat exchanger; a fluid path opening/closing valve for opening or closing a fluid path through which a refrigerant can flow to the outdoor heat exchanger; and a control unit for controlling the compressor and the fluid path opening/closing valve to perform appropriate compression and condensation of the refrigerant according to the load amount of the indoor unit. Accordingly, as the air conditioner comprises the fluid path opening/closing valve and the branch fluid path opening/closing valve which are capable of opening or closing fluid paths and a control unit for controlling the valves, a high pressure of a cycle is appropriately maintained even during small-load operation and therefore reliability in operation can be increased.

Abstract: An apparatus for controlling a refrigerant level comprises a first detecting unit installed at a lower side of the inside of a refrigerant tank, for detecting whether a refrigerant stored at a lower side of the inside of the refrigerant is a liquefied refrigerant or a gaseous refrigerant, a second detecting unit installed at an upper side of the inside of the refrigerant tank, for detecting whether a refrigerant stored at an upper side of the inside of the refrigerant tank is a liquefied refrigerant and a gaseous refrigerant, and a control unit controlling intake and discharge of the liquefied refrigerant according to a value measured by the first detecting unit and the second detecting unit.

Abstract: An air-conditioner having a dual-refrigerant cycle includes a primary refrigerant circuit heat-exchanged with outdoor air; a secondary refrigerant circuit heat-exchanged with indoor air to perform either a cooling operation or a heating operation; and a heat exchange unit disposed between the primary refrigerant circuit and the secondary refrigerant circuit to perform heat exchange therebetween, wherein the secondary refrigerant circuit includes a compressor for compressing a refrigerant circulating in the secondary refrigerant circuit. A condensing pressure of the primary refrigerant circuit is lowered during the hating operation and an evaporation pressure of the primary refrigerant circuit is increased to thereby enhance efficiency of the air-conditioner.