# US 8,739,855 B2 · Microchannel heat exchanger > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,739,855 B2 - Document ID: US8739855B2 - Status: Granted - Kind: B2 - Application number: 13/402,966 - Filed: 2012-02-23 - Published: 2013-08-22 - Granted: 2014-06-03 - Earliest claimed: 2012-02-17 - Assignees: Hussmann Corporation - Applicants: Steve L. Fritz; Matthew J. DeKam - Inventors: Steve L. Fritz; Matthew J. DeKam - Web page: https://patentgrep.com/patent/US8739855B2 ## CPC - F25D 17/067: {Evaporator fan units} - F28D 1/0471: {the conduits having a non-circular cross-section (F28D1/0473, F28D1/0476, F28D1/0478 take precedence)} - F28D 1/05383: {with multiple rows of conduits or with multi-channel conduits (F28D1/05391 takes precedence)} - F28F 1/022: {with multiple channels} - F28F 1/126: {consisting of zig-zag shaped fins (F28F1/105 takes precedence)} - A47F 3/0482: {Details common to both closed and open types} - F25D 2500/02: Geometry problems - F25D 2500/06: Stock management - F28D 2021/0042: {for foodstuffs} - F28F 2260/02: having microchannels - F25D: REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR (refrigerated showcases A47F3/04; thermally-insulated vessels for domestic use A47J41/00; refrigerated vehicles, see the appropriate subclasses of classes B60 - B64; containers with thermal insulation in general B65D81/38; heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants, or materials for the production of heat or cold by chemical reactions other than by combustion C09K5/00; thermally-insulated vessels for liquefied or solidified gases F17C; air-conditioning or air-humidification F24F; refrigeration machines, plants, or systems F25B; cooling of instruments or comparable apparatus without refrigeration G12B) - F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general) - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) - A47F: SPECIAL FURNITURE, FITTINGS, OR ACCESSORIES FOR SHOPS, STOREHOUSES, BARS, RESTAURANTS OR THE LIKE; PAYING COUNTERS ## Abstract A heat exchanger includes an inlet header configured to receive a cooling fluid and an outlet header configured to discharge the cooling fluid. A plurality of microchannel tubes are in fluid communication with and extend between the inlet header and the outlet header. The microchannel tubes define a first heat exchanger region and a second heat exchanger region between the inlet header and the outlet header. The first heat exchanger region has a plurality of fins defining a first fin density that is greater than a second fin density of the second heat exchanger region. ## Claims ### Claim 1 A cooling system comprising: a first flue and a second flue cooperatively defining an air passageway; a fan disposed in the air passageway to generate an airflow through the first and second flue; and an evaporator in communication with at least one of the first flue and the second flue for cooling the airflow, the evaporator comprising an inlet header configured to receive a cooling fluid; an outlet header configured to discharge the cooling fluid; and a plurality of microchannel tubes in fluid communication with and extending between the inlet header and the outlet header, the microchannel tubes defining a first side of the heat exchanger between the inlet header and the outlet header and an opposed second side of the heat exchanger between the inlet header and the outlet header, wherein the first and second flue define a bend in the air passageway, and further wherein the evaporator is positioned at the bend such that the airflow passes from the first side to the second side in a first direction and then passes from the second side to the first side in a second direction different from the first direction. ### Claim 2 (depends on 1) The system of claim 1, wherein the evaporator is defined by a first heat exchanger region that extends from one of the outlet header and the inlet header to a point between the inlet header and the outlet header and a second heat exchanger region that extends from the other of the outlet header and the inlet header to the point. ### Claim 3 (depends on 2) The system of claim 2, wherein the first heat exchanger region has a plurality of fins defining a first density and the second heat exchanger region has a plurality of fins defining a second fin density that is different from the first fin density. ### Claim 4 (depends on 3) The system of claim 3, wherein the second fin density is less than the first fin density. ### Claim 5 (depends on 3) The system of claim 3, wherein the first fin density is between about 3 fins per inch and about 24 fins per inch. ### Claim 6 (depends on 2) The system of claim 2, wherein the first heat exchanger region has a plurality of fins and the second heat exchanger region is devoid of fins. ### Claim 7 (depends on 2) The system of claim 2, wherein the evaporator is disposed within the air passageway such that the airflow generated by the fan passes through the first heat exchanger region only after passing through the second heat exchanger region. ### Claim 8 (depends on 1) The system of claim 1, wherein the plurality of microchannel tubes extends linearly between the inlet header and the outlet header.