# US 2016/0252284 A1 · Air conditioning system and control method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0252284 A1 - Document ID: US20160252284A1 - Status: Published application - Kind: A1 - Application number: 15/025,794 - Filed: 2014-09-26 - Published: 2016-09-01 - Earliest claimed: 2013-09-30 - Assignees: Daikin Industries, Ltd. - Applicants: Daikin Industries, Ltd. - Inventors: Kousuke KIBO; Tadafumi NISHIMURA - Web page: https://patentgrep.com/patent/US20160252284A1 ## CPC - F25B 49/02: for compression type machines, plants or systems - F24F 11/30: for purposes related to the operation of the system, e.g. for safety or monitoring - F24F 11/46: Improving electric energy efficiency or saving - F24F 11/56: Remote control - F24F 11/63: Electronic processing - F24F 11/75: for maintaining constant air flow rate or air velocity - F24F 11/77: by controlling the speed of ventilators - F24F 11/84: using valves - F24F 11/86: by controlling compressors within refrigeration or heat pump circuits - F24F 11/89: Arrangement or mounting of control or safety devices - F25B 13/00: Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) - F24F 2110/10: Temperature - F24F 2140/12: Heat-exchange fluid pressure - F24F 2140/20: Heat-exchange fluid temperature - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS - F24F: AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B15/00; vertical ducts for carrying away waste gases from buildings E04F17/02; tops for chimneys or ventilating shafts, terminals for flues F23L17/02) ## Abstract An air conditioning system includes a plurality of indoor units installed in the same indoor space, an outdoor unit and a control device. The indoor units include respective usage-side heat exchangers capable of setting set temperatures individually. The outdoor unit includes a heat-source-side heat exchanger. The control device performs temperature control using a thermo-ON condition set in advance in accordance with the set temperatures, and relaxes the thermo-ON condition of thermo-OFF indoor units when the indoor units include both those that are thermo-ON and those that are thermo-OFF and a predetermined condition is satisfied. The predetermined condition is that at least one of the plurality of indoor units continues to be thermo-ON for a first elapsed time or longer, and at least one of the plurality of indoor units continues to be thermo-OFF for a second elapsed time or longer. ## Claims ### Claim 1 An air conditioning system, comprising: a plurality of indoor units installed in a same indoor space, the indoor units including respective usage-side heat exchangers and being capable of setting set temperatures individually; an outdoor unit including a heat-source-side heat exchanger arranged and configured to conduct heat exchange with refrigerant circulating through the usage-side heat exchangers; and a control device configured to perform temperature control of the same indoor space for each indoor unit, using a thermo-ON condition set in advance in accordance with the set temperatures, and to relax the thermo-ON condition of thermo-OFF indoor units when the indoor units include both those that are thermo-ON and those that are thermo-OFF and a predetermined condition is satisfied, the predetermined condition being that at least one of the plurality of indoor units continues to be thermo-ON for a first elapsed time or longer, and at least one of the plurality of indoor units continues to be thermo-OFF for a second elapsed time or longer. ### Claim 2 (depends on 1) The air conditioning system according to claim 1, wherein the control device relaxes the thermo-ON condition without altering a thermo-OFF condition. ### Claim 3 (depends on 1) The air conditioning system according to claim 1, wherein the control device appoints an operating condition of the outdoor unit so as to satisfy a highest increase requirement of increase requirements of air-conditioning capability of the plurality of indoor units. ### Claim 4 (depends on 3) The air conditioning system according to claim 3, wherein the control device has a required temperature calculation unit configured to calculate required evaporation temperatures or required condensation temperatures of the usage-side heat exchanger for each of the indoor units, and a target value appointing unit configured to appoint a target evaporation temperature based on a minimum value of the required evaporation temperatures of the indoor units calculated in the required temperature calculation units, or a target condensation temperature based on a maximum value of the required condensation temperatures of the indoor units calculated in the required temperature calculation units. ### Claim 5 (canceled) ### Claim 6 (depends on 1) The air conditioning system according to claim 1, wherein the thermo-ON condition is a condition that the indoor units be thermo-ON when there is a predetermined temperature difference between the set temperature and a control temperature; and the control device relaxes the thermo-ON condition by reducing the predetermined temperature difference of the thermo-ON condition, ### Claim 7 (depends on 1) The air conditioning system according to claim 1, wherein a plurality of the indoor units further include respective air blowers useable to adjust airflow volumes directed to the usage-side heat exchangers; and the control device adjusts the air blowers of the indoor units to reduce the airflow volumes when air-conditioning capabilities are excessive and to increase the airflow volumes when the air-conditioning capabilities are insufficient. ### Claim 8 (depends on 1) The air conditioning system according to claim 1, wherein the indoor units further include respective expansion mechanisms capable of adjusting degrees of superheat or degrees of subcooling in the outlet sides of the usage-side heat exchangers; and the control device adjusts the opening degrees of the expansion mechanisms in the indoor units to reduce the degrees of superheat or degrees of subcooling when the air-conditioning capabilities are excessive and to increase the degrees of superheat or degrees of subcooling when the air-conditioning capabilities are insufficient. ### Claim 9 (depends on 1) The air conditioning system according to claim 1, wherein the control device is centralized controller that acquires data from the outdoor unit and a plurality of the indoor units and sends data to the outdoor unit and a plurality of the indoor units. ### Claim 10 A method for controlling an air conditioning system including: a plurality of indoor units installed in a same indoor space, the indoor units including respective usage-side heat exchangers and being capable of setting set temperatures individually, and an outdoor unit including a heat-source-side heat exchanger arranged and configured to conduct heat exchange with refrigerant circulating through the usage-side heat exchangers, the method comprising: a first step of causing temperature control of the same indoor space to be performed in each indoor unit, using a thermo-ON condition set in advance in accordance with the set temperatures; and a second step of relaxing the thermo-ON condition of thermo-OFF indoor units when the indoor units include both those that are thermo-ON and those that are thermo-OFF and a predetermined condition is satisfied, the predetermined condition being that at least one of the plurality of indoor units continues to be thermo-ON for a first elapsed time or longer, and at least one of the plurality of indoor units continues to be thermo-OFF for a second elapsed time or longer.