# US 2018/0023866 A1 · Ultrahigh-Performance Radiative Cooler > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0023866 A1 - Document ID: US20180023866A1 - Status: Published application - Kind: A1 - Application number: 15/651,595 - Filed: 2017-07-17 - Published: 2018-01-25 - Earliest claimed: 2016-07-19 - Assignees: The Board of Trustees of the Leland Stanford Junior University - Applicants: The Board of Trustees of the Leland Stanford Junior University - Inventors: Zhen Chen; Linxiao Zhu; Aaswath Raman; Eli A. Goldstein; Shanhui Fan - Web page: https://patentgrep.com/patent/US20180023866A1 ## CPC - F25B 23/003: {using selective radiation effect} - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS ## Abstract A radiative cooler is provided having a thermally insulated vacuum chamber housing that is configured to support a vacuum level of at least 10-5 Torr, an infared-transparent window that is sealably disposed on top of the thermally insulated vacuum chamber and is transparet in the range of 8-13 μm, a selective emitter disposed inside the chamber, a mirror cone on the infared-transparent window, a selective emitter inside the chamber and is configured to passively dissipate heat from the earth into outer space through the infared-transparent window and is thermally decoupled from ambient air and solar irradiation but coupled to outer space, a heat exchanger with inlet and outlet pipes disposed below the selective emitter to cool water flowing through the pipe, a sun shade disposed vertically outside the chamber to minimize direct solar irradiation, and a mirror cone to minimize downward atmospheric radiation. ## Claims ### Claim 1 1) A radiative cooler, comprising: a) a thermally insulated vacuum chamber housing, wherein said thermally insulated vacuum chamber housing is configured to support a vacuum level of at least 10-5 Torr; b) an infared-transparent window, wherein said infared-transparent window is sealably disposed on top of said thermally insulated vacuum chamber, wherein said infared-transparent window has a transparency in the range of 8-13 μm; c) a selective emitter, wherein said selective emitter is disposed inside said thermally insulated vacuum chamber housing; d) a mirror cone, wherein said mirror cone comprises an open bottom, wherein said open bottom of said mirror cone is disposed on said infared-transparent window and surrounds said infared-transparent window, wherein said mirror cone is configured to reduce downward atmospheric radiation bombarding on said selective emitter; e) a selective emitter, wherein said selective emitter is disposed proximal to said infared-transparent window inside said thermally insulated vacuum chamber housing, wherein said a selective emitter is configured to passively dissipate heat from the earth into outer space through said infared-transparent window, wherein said selective emitter is thermally decoupled from ambient air and solar irradiation but coupled to outer space; f) radiation shields and ceramic support pegs, wherein each said radiation shield comprises holes for receiving said ceramic support pegs, wherein said radiation shields are disposed in a stack on said ceramic support pegs, wherein each said radiation shields are separated by ceramic washers, wherein said radiation shields are disposed below said selective emitter inside said thermally insulated vacuum chamber housing; and g) a sun shade, wherein said sun shade is disposed vertically outside said thermally insulated housing and said mirror cone, wherein said sun shade is configured to minimize direct solar irradiation. ### Claim 2 (depends on 1) 2) The radiative cooler according to claim 1, wherein said infared-transparent window comprises a ZnSe window. ### Claim 3 (depends on 1) 3) The radiative cooler according to claim 1, wherein said infared-transparent window comprises a double-side antireflection coating. ### Claim 4 (depends on 1) 4) The radiative cooler according to claim 1, wherein said selective emitter comprises layers of silicon nitride (Si3N4), silicon (Si), and aluminum (Al) disposed on a substrate. ### Claim 5 (depends on 1) 5) The radiative cooler according to claim 1, wherein said selective emitter comprises a backside reflection coating. ### Claim 6 6) A radiative cooler, comprising: a) a thermally insulated housing, wherein said thermally insulated housing comprises hollow walls, wherein said hollow walls are configured to support a vacuum level of at least 10-5 Torr; b) an infared-transparent window, wherein said infared-transparent window is sealably disposed on top of said thermally insulated housing, wherein said infared-transparent window has a transparency in the range of 8-13 μm; c) a mirror cone, wherein said mirror cone comprises an open bottom, wherein said open bottom of said mirror cone is disposed on said infared-transparent window and surrounds said infared-transparent window, wherein said mirror cone is configured to reduce downward atmospheric radiation bombarding on said selective emitter; d) a selective emitter, wherein a top side of said selective emitter is disposed proximal to said infared-transparent window inside said thermally insulated vacuum chamber housing, wherein said a selective emitter is configured to passively dissipate heat from the earth into outer space through said infared-transparent window, wherein said selective emitter is thermally decoupled from ambient air and solar irradiation but coupled to outer space; e) ceramic support pegs, wherein said ceramic support pegs are disposed on an inner bottom surface of said thermally insulated vacuum chamber housing and configured to support said selective emitter; and f) a sun shade, wherein said sun shade is disposed vertically outside said thermally insulated chamber housing and said mirror cone, wherein said sun shade is configured to minimize direct solar irradiation. ### Claim 7 (depends on 6) 7) The radiative cooler according to claim 6, wherein said infared-transparent window comprises a polyethylene thin film. ### Claim 8 (depends on 6) 8) The radiative cooler according to claim 6, wherein said selective emitter comprises layers of silicon nitride (Si3N4), silicon (Si), and aluminum (Al) disposed on a substrate. ### Claim 9 (depends on 6) 9) The radiative cooler according to claim 6, wherein said selective emitter comprises a backside reflection coating. ### Claim 10 10) A radiative cooler, comprising: a) a thermally insulated housing, wherein said thermally insulated housing comprises hollow walls, wherein said hollow walls are configured to support a vacuum level of at least 10-5 Torr; b) an infared-transparent window, wherein said infared-transparent window is sealably disposed on top of said thermally insulated housing, wherein said infared-transparent window has a transparency in the range of 8-13 μm; c) a mirror cone, wherein said mirror cone comprises an open bottom, wherein said open bottom of said mirror cone is disposed on said infared-transparent window and surrounds said infared-transparent window, wherein said mirror cone is configured to reduce downward atmospheric radiation bombarding on said selective emitter; d) a selective emitter, wherein a top side of said selective emitter is disposed proximal to said infared-transparent window inside said thermally insulated housing, wherein said a selective emitter is configured to passively dissipate heat from the earth into outer space through said infared-transparent window, wherein said selective emitter is thermally decoupled from ambient air and solar irradiation but coupled to outer space; e) a plate heat exchanger, wherein said plate heat exchanger is in contact with a bottom side of said selective emitter, wherein said plate heat exchanger comprises an inlet pipe and an outlet pipe, wherein said inlet pipe and said outlet pipe are configured to pass and cool a fluid into said inlet pipe and out of said outlet pipe; and f) a sun shade, wherein said sun shade is disposed vertically outside said thermally insulated housing and said mirror cone, wherein said sun shade is configured to minimize direct solar irradiation. ### Claim 11 (depends on 10) 11) The radiative cooler according to claim 10, wherein said infared-transparent window comprises a polyethylene thin film. ### Claim 12 (depends on 10) 12) The radiative cooler according to claim 10, wherein said selective emitter comprises layers of silicon nitride (Si3N4), silicon (Si), and aluminum (Al) disposed on a substrate. ### Claim 13 (depends on 10) 13) The radiative cooler according to claim 10, wherein said selective emitter comprises a backside reflection coating.