# US 2019/0376733 A1 · Heat source unit and air conditioner having the heat source unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0376733 A1 - Document ID: US20190376733A1 - Status: Published application - Kind: A1 - Application number: 16/481,265 - Filed: 2018-02-09 - Published: 2019-12-12 - Earliest claimed: 2017-02-10 - Assignees: Daikin Industries, Ltd.; Daikin Europe N.V. - Applicants: Daikin Industries, Ltd.; Daikin Europe N.V. - Inventors: Pieter Pirmez; Satoshi Kawano; Akiharu Kojima - Web page: https://patentgrep.com/patent/US20190376733A1 ## CPC - F25B 49/02: for compression type machines, plants or systems - F24F 1/18: characterised by their shape - F24F 1/24: Cooling of electric components - F24F 1/46: Component arrangements in separate outdoor units - F24F 11/84: using valves - F25B 13/00: Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) - F25B 31/006: {Cooling of compressor or motor} - F25B 41/24: Arrangement of shut-off valves for disconnecting a part of the refrigerant cycle, e.g. an outdoor part - F25B 49/022: {Compressor control arrangements} - F25B 2313/021: Indoor unit or outdoor unit with auxiliary heat exchanger not forming part of the indoor or outdoor unit - F25B 2600/0253: with variable speed - F25B 2600/2501: Bypass valves - F25B 2600/2519: On-off valves - F25B 2700/1933: Suction pressures - F25B 2700/2104: of an indoor room or compartment - F25B 2700/21173: at the outlet - 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 A heat source unit for an air conditioner that includes a refrigerant circuit, the heat source unit includes: an external housing; and a cooling heat exchanger disposed in the external housing and that is connected to the refrigerant circuit. The external housing accommodates: a compressor connected to the refrigerant circuit; a heat source heat exchanger that is connected to the refrigerant circuit and that exchanges heat between a refrigerant circulating in the refrigerant circuit and a heat source; and an electric box. The electrical box: includes a top and a plurality of side walls; accommodates electrical components that control the air conditioner; and further includes an air passage that includes an air inlet and an air outlet. An air flow is induced through the air passage from the air inlet to the air outlet for cooling at least some of the electrical components. ## Claims ### Claim 1 A heat source unit for an air conditioner that comprises a refrigerant circuit, the heat source unit comprising: an external housing that accommodates: a compressor connected to the refrigerant circuit; a heat source heat exchanger that is connected to the refrigerant circuit and that exchanges heat between a refrigerant circulating in the refrigerant circuit and a heat source; and an electric box that: includes a top and a plurality of side walls; accommodates electrical components that control the air conditioner; and further includes an air passage comprising an air inlet and an air outlet, wherein an air flow is induced through the air passage from the air inlet to the air outlet for cooling at least some of the electrical components; a cooling heat exchanger disposed in the external housing and that is connected to the refrigerant circuit, wherein the air flow flows through the cooling heat exchanger, and the cooling heat exchanger exchanges heat between the refrigerant and the air flow, and is connected to a bypass line disposed between a liquid refrigerant line and a gas suction line; a valve disposed on the bypass line upstream of the cooling heat exchanger; and a controller that controls the valve to switch between an OFF-mode in which the valve is closed and an ON-mode in which the valve is opened. ### Claim 2 (depends on 1) The heat source unit according to claim 1, further comprising a capillary disposed on the bypass line upstream of the cooling heat exchanger. ### Claim 3 (depends on 1) The heat source unit according to claim 1, wherein the controller allows manual setting of the OFF-mode. ### Claim 4 (depends on 1) The heat source unit according to claim 1, wherein the controller switches between the OFF-mode and the ON-mode based on operation conditions of the air conditioner. ### Claim 5 (depends on 4) The heat source unit according to claim 4, wherein the controller switches the valve to the OFF-mode when a required cooling capacity of the air conditioner exceeds a predetermined threshold. ### Claim 6 (depends on 4) The heat source unit according to claim 4, wherein the controller switches the valve to the OFF-mode during special control modes of the air conditioner, wherein the special control modes include a start-up of the air conditioner and oil return operations. ### Claim 7 (depends on 1) The heat source unit according to claim 1, further comprising: a temperature sensor disposed within the external housing, wherein the controller switches between the ON-mode and the OFF-mode of the valve based on a temperature measured by the temperature sensor. ### Claim 8 (depends on 7) The heat source unit according to claim 7, wherein the controller switches to the ON-mode when the temperature measured by the temperature sensor is higher than a predetermined temperature. ### Claim 9 (depends on 1) The heat source unit according to claim 1, further comprising: a third temperature sensor disposed at an exit line between an exit of the cooling heat exchanger and a connection of the bypass line to the gas suction line, wherein the controller: determines a superheat degree of the refrigerant in the exit line based on a temperature detected by the third temperature sensor, and switches between the ON-mode and the OFF-mode of the valve based on the determined superheat degree. ### Claim 10 (depends on 9) The heat source unit according to claim 9, wherein the controller switches to the OFF-mode of the valve when the superheat degree falls below a predetermined value for a predetermined period of time. ### Claim 11 (depends on 1) The heat source unit according to claim 1, wherein the external housing comprises vents. ### Claim 12 An air conditioner comprising: a refrigerant circuit; and a heat source unit that comprises: an external housing that accommodates: a compressor connected to the refrigerant circuit; a heat source heat exchanger that is connected to the refrigerant circuit and that exchanges heat between a refrigerant circulating in the refrigerant circuit and a heat source; and an electric box that: includes a top and a plurality of side walls; accommodates electrical components that control the air conditioner; and further includes an air passage comprising an air inlet and an air outlet, wherein an air flow is induced through the air passage from the air inlet to the air outlet for cooling at least some of the electrical components; a cooling heat exchanger disposed in the external housing and that is connected to the refrigerant circuit, wherein the air flow flows through the cooling heat exchanger, and the cooling heat exchanger exchanges heat between the refrigerant and the air flow, and is connected to a bypass line disposed between a liquid refrigerant line and a gas suction line; a valve disposed on the bypass line upstream of the cooling heat exchanger; and a controller that controls the valve to switch between an OFF-mode in which the valve is closed and an ON-mode in which the valve is opened, wherein the heat source unit is connected to at least one indoor unit that comprises an indoor heat exchanger that forms the refrigerant circuit. ### Claim 13 (depends on 12) The air conditioner according to claim 12, wherein the heat source unit is disposed in an installation space. ### Claim 14 (depends on 13) The air conditioner according to claim 13, further comprising: a temperature sensor disposed in the installation space, wherein the controller switches to the ON-mode depending on a delta between the temperature measured by the temperature sensor and a predetermined temperature. ### Claim 15 (depends on 12) The air conditioner according to claim 12, wherein the controller switches: to the ON-mode when a difference between a first heat transfer capacity of the air conditioner at an indoor unit side and a second heat transfer capacity of the air conditioner at an indoor unit side is higher than a heat transfer capacity of the cooling heat exchanger and to the OFF-mode when a difference between the first heat transfer capacity of the air conditioner and the second heat transfer capacity of the air conditioner is lower than the heat transfer capacity of the cooling heat exchanger, the first heat transfer capacity of the air conditioner is a heat transfer capacity during a first operation mode in which the compressor is driven at a first frequency, and the second heat transfer capacity of the air conditioner is a heat transfer capacity during a second operation mode in which the compressor is driven at a second frequency that is lower than the first frequency.