# US 12,111,067 B2 · Air conditioning system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,111,067 B2 - Document ID: US12111067B2 - Status: Granted - Kind: B2 - Application number: 17/603,758 - Filed: 2020-04-15 - Published: 2022-06-09 - Granted: 2024-10-08 - Earliest claimed: 2019-04-15 - Assignees: Daikin Industries, Ltd. - Applicants: Daikin Industries, Ltd. - Inventors: Shuuichi Tanaka; Yoshiteru Nouchi - Web page: https://patentgrep.com/patent/US12111067B2 ## CPC - F24F 3/001: {in which the air treatment in the central station takes place by means of a heat-pump or by means of a reversible cycle (reversible cycle for humidifying and drying air F24F3/147)} - F24F 11/74: for controlling air flow rate or air velocity - F24F 3/044: Systems in which all treatment is given in the central station, i.e. all-air systems - F24F 11/77: by controlling the speed of ventilators - F24F 11/79: for controlling the direction of the supplied air - F24F 11/84: using valves - F24F 11/89: Arrangement or mounting of control or safety devices - Y02B 30/70: Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating - 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) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract An air conditioning system configured to supply a plurality of places in a building with conditioned air with use of ducts inhibits malfunction of the air conditioning system due to airflow volume through a utilization heat exchanger. A heat exchanger unit includes a utilization heat exchanger. The heat exchanger unit is connected with a plurality of ducts. A plurality of fan units sucks conditioned air from the heat exchanger unit through the plurality of ducts and supplies a plurality of blow-out ports with the conditioned air. The fan units include fan motors as a plurality of actuators configured to individually change supply air volume of the conditioned air. A main controller controls the plurality of fan motors such that airflow volume through the utilization heat exchanger satisfies a predetermined condition. ## Claims ### Claim 1 An air conditioning system comprising: a heat exchanger unit having a utilization heat exchanger and configured to generate conditioned air through heat exchange in the utilization heat exchanger and supply an air conditioning target space with the conditioned air through a plurality of distribution flow paths communicating with the heat exchanger unit, each of the plurality of distribution flow paths including a duct connected to the heat exchanger unit and provided for distribution of the conditioned air, a fan unit provided correspondingly to the duct and configured to supply the air conditioning target space with the conditioned air from the heat exchanger unit through the duct, as well as an actuator configured to individually change supply air volume of the conditioned air supplied to the air conditioning target space, and the air conditioning system further comprising a main controller configured to control actuators in the plurality of distribution flow paths such that airflow volume through the utilization heat exchanger satisfies a predetermined condition, wherein the predetermined condition is to cause the airflow volume through the utilization heat exchanger to be more than a lower limit value of airflow that causes malfunction caused by insufficient heat exchange in the utilization heat exchanger. ### Claim 2 (depends on 1) The air conditioning system according to claim 1, wherein at least either ducts or fan units each include an airflow volume sensor, and the main controller is configured to obtain a total airflow volume of airflow through the distribution flow paths by detecting the airflow volume by airflow volume sensors and controlling the actuators such that the detected total airflow volume satisfies the predetermined condition. ### Claim 3 (depends on 2) The air conditioning system according to claim 2, wherein the actuators are fan motors of the fan units, and the main controller controls a number of revolution of each of the fan motors in accordance with values of the airflow volume sensors. ### Claim 4 (depends on 3) The air conditioning system according to claim 3, wherein each of the actuators includes a motor configured to adjust an opening degree of a damper included in each of the fan units, and the main controller controls the opening degrees of the dampers using motors in accordance with values of the airflow volume sensors. ### Claim 5 (depends on 2) The air conditioning system according to claim 2, wherein each of the actuators includes a motor configured to adjust an opening degree of a damper included in each of the fan units, and the main controller controls the opening degrees of the dampers using motors in accordance with values of the airflow volume sensors. ### Claim 6 (depends on 1) The air conditioning system according to claim 1, further comprising: a heat source device connected to the utilization heat exchanger, including a compressor, and constituting a refrigerant circuit configured to achieve a vapor compression refrigeration cycle along with the utilization heat exchanger, wherein the main controller links control of the actuators with control of the refrigerant circuit. ### Claim 7 (depends on 6) The air conditioning system according to claim 6, wherein the main controller activates the fan unit being stopped when the airflow volume through the utilization heat exchanger is less than the predetermined value in accordance with a command to reduce airflow volume of the fan unit. ### Claim 8 (depends on 6) The air conditioning system according to claim 6, wherein the main controller increases airflow volume of the fan unit when the airflow volume through the utilization heat exchanger is less than the predetermined value in accordance with a command to reduce the airflow volume of the fan unit. ### Claim 9 (depends on 1) The air conditioning system according to claim 1, wherein the main controller activates the fan unit being stopped when the airflow volume through the utilization heat exchanger is less than the predetermined value in accordance with a command to reduce airflow volume of the fan unit. ### Claim 10 (depends on 1) The air conditioning system according to claim 1, wherein the main controller increases airflow volume of the fan unit when the airflow volume through the utilization heat exchanger is less than the predetermined value in accordance with a command to reduce the airflow volume of the fan unit. ### Claim 11 An air conditioning comprising: a heat exchanger unit having a utilization heat exchanger and configured to generate conditioned air through heat exchange in the utilization heat exchanger and supply an air conditioning target space with the conditioned air through a plurality of distribution flow paths communicating with the heat exchanger unit, each of the plurality of distribution flow paths including a duct connected to the heat exchanger unit and provided for distribution of the conditioned air, a fan unit provided correspondingly to the duct and configured to supply the air conditioning target space with the conditioned air from the heat exchanger unit through the duct, as well as an actuator configured to individually change supply air volume of the conditioned air supplied to the air conditioning target space, and the air conditioning system further comprising a main controller configured to control actuators in the plurality of distribution flow paths such that airflow volume through the utilization heat exchanger satisfies a predetermined condition, wherein the predetermined condition is to cause the airflow volume through the utilization heat exchanger to be a predetermined value or more, and the air conditioning system further comprising: a heat source device connected to the utilization heat exchanger including a compressor, and constituting a refrigerant circuit configured to achieve a vapor compression refrigeration cycle along with the utilization heat exchanger, wherein the main controller links control of the actuators with control of the refrigerant circuit, and the predetermined value is set to vary in accordance with a parameter of the heat source device influencing a state or circulation volume of a refrigerant circulating in the refrigerant circuit. ### Claim 12 (depends on 11) The air conditioning system according to claim 11, wherein the parameter has a value relevant to the circulation volume. ### Claim 13 (depends on 12) The air conditioning system according to claim 12, wherein the main controller activates the fan unit being stopped when the airflow volume through the utilization heat exchanger is less than the predetermined value in accordance with a command to reduce airflow volume of the fan unit. ### Claim 14 (depends on 11) The air conditioning system according to claim 11, wherein the parameter includes at least one of condensation temperature of the refrigerant circuit, evaporation temperature of the refrigerant circuit, heat exchanger temperature of the utilization heat exchanger, an operating frequency of the compressor, a degree of superheating of the refrigerant circuit, a degree of subcooling of the refrigerant circuit, combination of inlet temperature and outlet temperature of the utilization heat exchanger, and combination of inlet pressure and the outlet temperature of the utilization heat exchanger. ### Claim 15 (depends on 14) The air conditioning system according to claim 14, wherein the main controller activates the fan unit being stopped when the airflow volume through the utilization heat exchanger is less than the predetermined value in accordance with a command to reduce airflow volume of the fan unit. ### Claim 16 (depends on 11) The air conditioning system according to claim 11, wherein the main controller activates the fan unit being stopped when the airflow volume through the utilization heat exchanger is less than the predetermined value in accordance with a command to reduce airflow volume of the fan unit.