Abstract: Disclosed herein is a method for operating an air conditioner which is capable of achieving the effective operation of a plurality of indoor units. The method comprises the steps of: a) receiving operating state information of the indoor units connected to one outdoor unit; b) determining whether or not the amount of refrigerant to be distributed into the indoor units needs to be regulated, based on the operating state information of the indoor units; and c) regulating the amount of the refrigerant to be distributed into the indoor units.

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 conditioner is disclosed which is capable of preventing frost from being formed on the outer surface of a refrigerant line. In order to control an air conditioner including an outdoor unit, a plurality of indoor units corresponding to the out door unit, and a plurality of refrigerant lines for connecting the indoor units to the outdoor unit, respectively, the method includes the steps of measuring respective states of the refrigerant lines using a measurement sensor, determining respective states of the refrigerant lines, based on measurement data obtained by the measurement sensor, and controlling an operation state of an operating one or operating ones of the indoor units, in accordance with the determined state of the refrigerant line associated with the operating indoor unit or each operating indoor unit.

Abstract: A control method of a multi-air conditioner in which a plurality of indoor units is connected to one outdoor unit and refrigerant flow amount is adjusted by electronic expansion valves comprises a share step in which a plurality of indoor units exchanges their operation information, a comparison and judgment step in which each above indoor unit compares and judges its operation status based on the exchanged operation information, and an adjustment step in which each above indoor unit adjusts refrigerant flow amount supplied to each indoor unit based on the compared and judged operation status.

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: A multi-unit air conditioner is disclosed. The multi-unit air conditioner includes an outdoor unit comprising at least two compressors, a plurality of indoor units connected to the outdoor unit, a plurality of oil separators each connected to an associated one of the compressors to separate oil from a refrigerant discharged from the associated compressor, an oil storage for storing the oil separated from each oil separator, a plurality of oil supplying tubes each having one end connected to the oil storage, and the other end connected to an associated one of the compressors to supply the oil stored in the oil storage to the associated compressor, and adjusters each arranged at an associated one of the oil supplying tubes to adjust an amount of oil supplied from the oil storage to an associated one of the compressors in accordance with an oil storage state of the associated compressor.

Abstract: Method for controlling a multi-type air conditioner having a plurality of indoor units each with an expansion valve, an indoor heat exchanger, and an indoor fan, some of which heat rooms, and rest of which are turned off, including the steps of (S11) defining a saturation temperature of refrigerant by using a heating cycle of the refrigerant, and Mollier chart, (S12) measuring a temperature of the refrigerant stagnant at the turned off indoor units, (S13) determining if a temperature difference of the refrigerant temperature and the saturation temperature is within a temperature range preset at a control part, (S14) opening the expansion valves of the turned off indoor units, if the temperature difference is within the temperature range preset at the control part, and (S15) closing the expansion valve of the turned off indoor units, if the temperature difference is not within the temperature range preset at the control part, whereby minimizing stagnation of refrigerant at turned off indoor units during some o

Abstract: An optical payment transceiver and an optical settlement system using the same uses a personal portable terminal incorporated with an optical transceiver as a card substitute payment unit for settlement. Here, card information is incorporated in a personal portable terminal incorporated with an optical transceiver such as a portable phone or a PDA and the optical transceiver is connected to a card inquiry machine to thereby optically transmit and receive card information. The card inquiry machine recognizes the received card information in the same manner as that of the card reader reading a magnetic card, and transmits the card information to a VAN company server or a card company server, to then request for an approval and settle transactions.