# US 2019/0170410 A1 · Heating, ventilation, air-conditioning, and refrigeration system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170410 A1 - Document ID: US20190170410A1 - Status: Published application - Kind: A1 - Application number: 15/830,919 - Filed: 2017-12-04 - Published: 2019-06-06 - Earliest claimed: 2017-12-04 - Assignees: Lennox Industries Inc. - Applicants: Lennox Industries Inc. - Inventors: Eric Berg; Austin Clay Styer; Carl T. Crawford - Web page: https://patentgrep.com/patent/US20190170410A1 ## CPC - F25B 29/003: {of the compression type system} - F25B 30/02: of the compression type - F25B 49/02: for compression type machines, plants or systems - F25B 49/022: {Compressor control arrangements} - F25B 41/39: Dispositions with two or more expansion means arranged in series, i.e. multi-stage expansion, on a refrigerant line leading to the same evaporator - F25B 2300/00: Special arrangements or features for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems - F25B 2313/029: Control issues - F25B 2400/0403: for condensers - F25B 2500/02: Increasing the heating capacity of a reversible cycle during cold outdoor conditions - F25B 2600/0253: with variable speed - F25B 2600/2501: Bypass valves - F25B 2700/19: Pressures - F25B 2700/21: Temperatures - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS ## Abstract An apparatus includes a high side heat exchanger, a second heat exchanger, a load, a variable speed compressor, and a three-way valve. The high side heat exchanger removes heat from a refrigerant. The second heat exchanger removes heat from the refrigerant. The load uses the refrigerant to remove heat from a space proximate the load. The variable speed compressor compresses the refrigerant from the load and directs the compressed refrigerant to the high side heat exchanger. The three-way valve, when operating in a first mode, directs the refrigerant from the high side heat exchanger to the load and when operating in a second mode, directs the refrigerant from the high side heat exchanger to the second heat exchanger. ## Claims ### Claim 1 An apparatus comprising: a high side heat exchanger configured to remove heat from a refrigerant; a second heat exchanger configured to remove heat from the refrigerant; a load configured to use the refrigerant to remove heat from a space proximate the load; a variable speed compressor configured to compress the refrigerant from the load and to direct the compressed refrigerant to the high side heat exchanger; and a three-way valve configured to: when operating in a first mode, direct the refrigerant from the high side heat exchanger to the load; and when operating in a second mode, direct the refrigerant from the high side heat exchanger to the second heat exchanger. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the second heat exchanger is further configured to direct the refrigerant in the second heat exchanger through a drain line to the variable speed compressor when the three-way valve is operating in the first mode. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the three-way valve is further configured to switch from operating in the first mode to the second mode when the variable speed compressor operates at a speed that is above a threshold. ### Claim 4 (depends on 1) The apparatus of claim 1, further comprising a temperature sensor configured to detect a temperature of the refrigerant, wherein the three-way valve is further configured to switch from operating in the first mode to the second mode when the detected temperature exceeds a threshold. ### Claim 5 (depends on 1) The apparatus of claim 1, further comprising a pressure sensor configured to detect a pressure of the refrigerant, wherein the three-way valve is further configured to switch from operating in the first mode to the second mode when the detected pressure exceeds a threshold. ### Claim 6 (depends on 1) The apparatus of claim 1, further comprising a first expansion valve and a second expansion valve, both the first and second expansion valves positioned between the high side heat exchanger and the load, the high side heat exchanger is a heat pump, and the three-way valve is positioned between the first expansion valve and the second expansion valve. ### Claim 7 (depends on 1) The apparatus of claim 1, further comprising a controller configured to switch the operation of the three-way valve between the first mode and the second mode. ### Claim 8 A method comprising: removing heat from a refrigerant using a high side heat exchanger; when operating in a first mode, directing the refrigerant from the high side heat exchanger to a load; when operating in a second mode: directing the refrigerant from the high side heat exchanger to a second heat exchanger; removing heat from the refrigerant using the second heat exchanger; and directing the refrigerant from the second heat exchanger to the load; using the refrigerant to remove heat from a space proximate the load; compressing the refrigerant from the load using a variable speed compressor; and directing the compressed refrigerant to the high side heat exchanger. ### Claim 9 (depends on 8) The method of claim 8, further comprising directing the refrigerant in the second heat exchanger through a drain line to the variable speed compressor when operating in the first mode. ### Claim 10 (depends on 8) The method of claim 8, further comprising switching from operating in the first mode to the second mode when the variable speed compressor operates at a speed that is above a threshold. ### Claim 11 (depends on 8) The method of claim 8, further comprising: detecting a temperature of the refrigerant; and switching from operating in the first mode to the second mode when the detected temperature exceeds a threshold. ### Claim 12 (depends on 8) The method of claim 8, further comprising: detecting a pressure of the refrigerant; and switching from operating in the first mode to the second mode when the detected pressure exceeds a threshold. ### Claim 13 (depends on 8) The method of claim 8, wherein a first expansion valve and a second expansion valve are positioned between the high side heat exchanger and the load, the high side heat exchanger is a heat pump, and a three-way valve is positioned between the first expansion valve and the second expansion valve. ### Claim 14 (depends on 8) The method of claim 8, further comprising switching between the first mode and the second mode using a controller. ### Claim 15 A system comprising: a high side heat exchanger configured to remove heat from a refrigerant; a second heat exchanger configured to remove heat from the refrigerant; a load configured to use the refrigerant to remove heat from a space proximate the load; a variable speed compressor configured to compress the refrigerant from the load and to direct the compressed refrigerant to the high side heat exchanger; a three-way valve configured to: when operating in a first mode, direct the refrigerant from the high side heat exchanger to the load; and when operating in a second mode, direct the refrigerant from the high side heat exchanger to the second heat exchanger; and a controller configured to switch the operation of the three-way valve between the first mode and the second mode. ### Claim 16 (depends on 15) The system of claim 15, wherein the second heat exchanger is further configured to direct the refrigerant in the second heat exchanger through a drain line to the variable speed compressor when the three-way valve is operating in the first mode. ### Claim 17 (depends on 15) The system of claim 15, wherein the three-way valve is further configured to switch from operating in the first mode to the second mode when the variable speed compressor operates at a speed that is above a threshold. ### Claim 18 (depends on 15) The system of claim 15, further comprising a temperature sensor configured to detect a temperature of the refrigerant, wherein the three-way valve is further configured to switch from operating in the first mode to the second mode when the detected temperature exceeds a threshold. ### Claim 19 (depends on 15) The system of claim 15, further comprising a pressure sensor configured to detect a pressure of the refrigerant, wherein the three-way valve is further configured to switch from operating in the first mode to the second mode when the detected pressure exceeds a threshold. ### Claim 20 (depends on 15) The system of claim 15, further comprising a first expansion valve and a second expansion valve, both the first and second expansion valves positioned between the high side heat exchanger and the load, the high side heat exchanger is a heat pump, and the three-way valve is positioned between the first expansion valve and the second expansion valve.