# US 10,371,393 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 10,371,393 B2 - Document ID: US10371393B2 - Status: Granted - Kind: B2 - Application number: 14/500,993 - Filed: 2014-09-29 - Published: 2015-04-02 - Granted: 2019-08-06 - Earliest claimed: 2013-09-30 - Assignees: Daikin Industries, Ltd. - Applicants: Daikin Industries, Ltd. - Inventors: Masakazu Okamoto; Michio Moriwaki; Hiroshi Yoh - Web page: https://patentgrep.com/patent/US10371393B2 ## CPC - F24D 19/1087: {system using a heat pump} - F24D 5/02: operating with discharge of hot air into the space or area to be heated - F24D 5/12: using heat pumps - F24H 15/144: Measuring or calculating energy consumption - F24H 15/156: Reducing the quantity of energy consumed; Increasing efficiency - F24H 15/16: Reducing cost using the price of energy, e.g. choosing or switching between different energy sources - F24H 15/231: at the evaporator - F24H 15/254: Room temperature - F24H 15/258: Outdoor temperature - F24H 15/345: Control of fans, e.g. on-off control (control of fans of heat pump units F24H15/375) - F24H 15/36: of burners - F24H 15/375: Control of heat pumps - F24H 15/38: Control of compressors of heat pumps - F24D 2200/04: Gas or oil fired boiler - F24D 2200/123: Compression type heat pumps - F24H 15/176: Improving or maintaining comfort of users - F24H 15/281: Input from user - F24H 15/395: Information to users, e.g. alarms - F24H 15/429: for selecting operation modes - Y02B 30/13: Hot air central heating systems using heat pumps - F24D: DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR (using steam or condensate extracted or exhausted from steam engine plants for heating purposes F01K17/02) - F24H: FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL (steam generation F22) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract An air conditioning system includes a heat pump having a refrigerant radiator, a gas furnace unit having a heating section to heat passing air, a blower generating air flow through the radiator and the heating section, and a controller controlling operation of the heat pump unit, the gas furnace unit, and the blower. The controller has a first operating mode in which the gas furnace unit operates alone as a heat source unit, a second operating mode in which the heat pump unit operates alone as a heat source unit, and a third operating mode in which the gas furnace unit and the heat pump unit operate at the same time as a heat source unit. The controller is configured to select the operating modes based on a parameter relating to outside air temperature that is the temperature of outside air. ## Claims ### Claim 1 An air conditioning system comprising: a heat pump unit that includes a refrigerant radiator; a gas furnace unit that includes a heating section configured to heat air passing through the heating section; a blower configured to generate an air flow that passes through the radiator and the heating section; a controller configured to control operation of the heat pump unit, the gas furnace unit, and the blower; and a first temperature sensor arranged and configured to detect the outside air temperature, the controller having operating modes including a first operating mode in which the controller causes the gas furnace unit to operate alone as a heat source unit, a second operating mode in which the controller causes the heat pump unit to operate alone as a heat source unit, and a third operating mode in which the controller causes the gas furnace unit and the heat pump unit to operate at the same time as a heat source unit, the controller being configured to select the operating modes based on a parameter relating to outside air temperature that is the temperature of outside air, the controller being further configured to select the first operating mode when the outside air temperature is less than a first standard value, the second operating mode when the outside air temperature is equal to or greater than a second standard value that is a higher temperature than the first standard value, and the third operating mode when the outside air temperature is equal to or greater than the first standard value and less than the second standard value, and the controller being further configured to calculate a total load of the heat source unit, in the third operating mode, an operating capacity of the gas furnace unit being set to be larger than an operating capacity of the heat pump unit when the total load of the heat source unit is larger than a predetermined value, and the operating capacity of the heat pump unit being set to be larger than the operating capacity of the gas furnace unit when the total load of the heat source unit is not larger than the predetermined value. ### Claim 2 (depends on 1) The air conditioning system according to claim 1, further comprising a second temperature sensor arranged and configured to detect an evaporation temperature of refrigerant in the heat pump unit, the controller being configured to select the first operating mode when the evaporation temperature is less than a third standard value, the second operating mode when the evaporation temperature is equal to or greater than a fourth standard value that is a higher temperature than the third standard value, and the third operating mode when the evaporation temperature is equal to or greater than the third standard value and less than the fourth standard value. ### Claim 3 (depends on 1) The air conditioning system according to claim 1, further comprising a third temperature sensor installed in a room and arranged and configured to detect an indoor temperature that is the temperature in the room, in the third operating mode the controller being configured to calculate a first load that is a heat load processed by the gas furnace unit among the total load of the heat source unit and a second load that is a heat load processed by the heat pump unit among the total load of the heat source unit based on the outside air temperature, the indoor temperature, and a preset temperature, and adjust operating capacities of the gas furnace unit and the heat pump unit based on the first load and the second load. ### Claim 4 (depends on 3) The air conditioning system according to claim 3, wherein the heat pump unit further includes a compressor configured to compress refrigerant, a rotating speed of the compressor is variably adjustable by the controller, and in the third operating mode the controller is configured to determine the rotating speed of the compressor based on the second load. ### Claim 5 (depends on 3) The air conditioning system according to claim 3, wherein the gas furnace unit further includes a combustion unit configured to have gas combust therein, and in the third operating mode the controller is configured to determine capacity of the combustion unit based on the first load. ### Claim 6 (depends on 1) The air conditioning system according to claim 1, further comprising a third temperature sensor installed in a room and arranged and configured to detect an indoor temperature that is the temperature in the room, the gas furnace unit further including a combustion unit configured to have gas combust therein, and in the third operating mode the controller being configured to cause the combustion unit to operate in a first state when a first difference value, which is a value obtained by subtracting the indoor temperature from a preset temperature, is equal to or greater than a first threshold value, and when the first difference value is less than the first threshold value, cause the combustion unit to operate in a second state in which the capacity is lower than in the first state or stop operation of the combustion unit. ### Claim 7 (depends on 1) The air conditioning system according to claim 1, further comprising a third temperature sensor installed in a room and arranged and configured to detect an indoor temperature that is the temperature in the room, the heat pump unit further including a compressor arranged and configured to compress gas refrigerant, a rotating speed of the compressor being variably adjustable by the controller, and in the third operating mode the controller being configured to set the rotating speed of the compressor to a first speed when a second difference value, which is a value obtained by subtracting a preset temperature from the indoor temperature, is less than a second threshold value, and when the second difference value is equal to or greater than the second threshold value, set the rotating speed of the compressor to a second speed lower than the first speed or stop driving of the compressor. ### Claim 8 (depends on 1) The air conditioning system according to claim 1, wherein in the third operating mode the controller is configured to cause one of the gas furnace unit and the heat pump unit to operate as a main heat source unit and cause the other of the gas furnace unit and the heat pump unit to operate as an auxiliary heat source unit, calculate a first cost when causing the gas furnace unit to operate as the main heat source unit and a second cost when causing the heat pump unit to operate as the main heat source unit, cause the gas furnace unit to operate as the main heat source unit and cause the heat pump unit to operate as the auxiliary heat source unit when the first cost is lower than the second cost, cause the heat pump unit to operate as the main heat source unit and cause the gas furnace unit to operate as the auxiliary heat source unit when the first cost is higher than the second cost, calculate a third load that is the heat load processed by the auxiliary heat source unit, and adjust the operating capacity of the auxiliary heat source unit based on the third load. ### Claim 9 (depends on 2) The air conditioning system according to claim 2, further comprising a third temperature sensor installed in a room and arranged and configured to detect an indoor temperature that is the temperature in the room, in the third operating mode the controller being configured to calculate a first load that is the heat load processed by the gas furnace unit among the total load of the heat source unit and a second load that is the heat load processed by the heat pump unit among the total load of the heat source unit based on the outside air temperature, the indoor temperature, and a preset temperature, and adjust operating capacities of the gas furnace unit and the heat pump unit based on first load and the second load. ### Claim 10 (depends on 9) The air conditioning system according to claim 9, wherein the heat pump unit further includes a compressor arranged and configured to compress refrigerant, a rotating speed of the compressor is variably adjustable by the controller, and in the third operating mode the controller is configured to decide rotating speed of the compressor based on the second load. ### Claim 11 (depends on 4) The air conditioning system according to claim 4, wherein the gas furnace unit further includes a combustion unit arranged and configured to combust gas therein, and in the third operating mode the controller is configured to decide capacity of the combustion unit based on the first load. ### Claim 12 (depends on 2) The air conditioning system according to claim 2, further comprising a third temperature sensor installed in a room and arranged and configured to detect an indoor temperature that is the temperature in the room, the gas furnace unit further including a combustion unit arranged and configured to combust gas therein, and in the third operating mode the controller being configured to cause the combustion unit to operate in a first state when a first difference value, which is a value obtained by subtracting the indoor temperature from a preset temperature, is equal to or greater than a first threshold value, and when the first difference value is less than the first threshold value, cause the combustion unit to operate in a second state in which the capacity is lower than it is in the first state or stop operation of the combustion unit. ### Claim 13 (depends on 2) The air conditioning system according to claim 2, further comprising a third temperature sensor installed in a room and arranged and configured to detect an indoor temperature that is the temperature in the room, the heat pump unit further including a compressor arranged and configured to compress gas refrigerant, a rotating speed of the compressor being variably adjustable by the controller, and in the third operating mode the controller being configured to set the rotating speed of the compressor to a first speed when a second difference value, which is a value obtained by subtracting a preset temperature from the indoor temperature, is less than a second threshold value, and when the second difference value is equal to or greater than the second threshold value, set the rotating speed of the compressor to a second speed lower than the first speed or stop driving of the compressor. ### Claim 14 (depends on 2) The air conditioning system according to claim 2, wherein in the third operating mode the controller is configured to cause one of the gas furnace unit and the heat pump unit to operate as a main heat source unit and cause the other of the gas furnace unit and the heat pump unit to operate as an auxiliary heat source unit, calculate a first cost when causing the gas furnace unit to operate as the main heat source unit and a second cost when causing the heat pump unit to operate as the main heat source unit, cause the gas furnace unit to operate as the main heat source unit and cause the heat pump unit to operate as the auxiliary heat source unit when the first cost is lower than the second cost, cause the heat pump unit to operate as the main heat source unit and cause the gas furnace unit to operate as the auxiliary heat source unit when the first cost is higher than the second cost, calculate a third load that is the heat load processed by the auxiliary heat source unit, and adjust the operating capacity of the auxiliary heat source unit based on the third load.