# US 8,769,969 B2 · Defrost bypass dehumidifier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,769,969 B2 - Document ID: US8769969B2 - Status: Granted - Kind: B2 - Application number: 13/659,684 - Filed: 2012-10-24 - Published: 2013-03-07 - Granted: 2014-07-08 - Earliest claimed: 2005-11-16 - Assignees: Technologies Holdings Corp. - Applicants: Technologies Holdings Corp. - Inventors: Todd DeMonte; Scott E. Sloan; Steve S. Dingle; Timothy S. O'Brien; Phillip R. Steinmetz - Web page: https://patentgrep.com/patent/US8769969B2 ## CPC - F24F 3/1405: {in which the humidity of the air is exclusively affected by contact with the evaporator of a closed-circuit cooling system or heat pump circuit} - F24F 1/04: Arrangements for portability - F24F 3/153: with subsequent heating, i.e. with the air, given the required humidity in the central station, passing a heating element to achieve the required temperature - F24F 12/006: {using an air-to-air heat exchanger (F24F12/002 takes precedence)} - Y02B 30/56: Heat recovery units - 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) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A defrost bypass dehumidifier includes an air flow path with first, second and third segments in series from upstream to downstream and passing ambient air respectively to an evaporator coil then to a condenser coil and then discharging same. The air flow path has a bypass segment passing ambient air to the evaporator coil in parallel with the noted first air flow path segment. ## Claims ### Claim 1 A dehumidifier comprising: a cabinet; a compressor in the cabinet for delivering hot compressed refrigerant; a condenser coil in the cabinet and receiving refrigerant from the compressor and condensing same; an expansion device in the cabinet and receiving refrigerant from the condenser coil and expanding same; an evaporator coil in the cabinet and receiving refrigerant from the expansion device and evaporating same, and delivering the refrigerant to the compressor; the refrigerant being circulated from the compressor to the condenser coil to the expansion device to the evaporator coil and back to the compressor in a refrigeration cycle; the cabinet having an airflow path therethrough comprising: a first segment passing ambient air through a heat exchanger to the evaporator coil, a second segment passing air from the evaporator coil to the condenser coil, a third segment discharging air from the condenser coil, a fourth segment passing ambient air to the evaporator coil; and a first bypass door selectively positionable to variably control airflow along the fourth segment. ### Claim 2 (depends on 1) The dehumidifier according to claim 1, wherein the fourth segment of airflow passes ambient air to the evaporator coil in parallel with the first segment of airflow path and bypasses the heat exchanger. ### Claim 3 (depends on 1) The dehumidifier according to claim 1, further comprising an actuator structured to move the first bypass door between an open position to allow the airflow along the fourth segment and a closed position to block the air flow along the fourth segment. ### Claim 4 (depends on 3) The dehumidifier according to claim 3, further comprising a controller configured to selectively actuate the actuator and thereby selectively move the first bypass door between the open and closed positions. ### Claim 5 (depends on 4) The dehumidifier according to claim 4, further comprising a sensor configured to sense an operational parameter of the dehumidifier and to communicate the parameter to the controller, wherein the controller is further configured to actuate the actuator based upon the sensed parameter. ### Claim 6 (depends on 5) The dehumidifier according to claim 5, wherein the controller is configured to actuate the actuator when the sensed parameter is outside of a predetermined range. ### Claim 7 (depends on 6) The dehumidifier according to claim 6, wherein the controller comprises a memory stored with the predetermined range and an operating platform that is configured to compare the sensed parameter to the predetermined range and to then actuate the actuator when the parameter is outside of the predetermined range. ### Claim 8 (depends on 7) The dehumidifier according to claim 7, wherein the controller is configured to identify an optimal first bypass door position based upon the comparison and then actuate the actuator to move the first bypass door to the optimal first bypass door position. ### Claim 9 (depends on 8) The dehumidifier according to claim 8, wherein the sensed parameter comprises the temperature of ambient air. ### Claim 10 (depends on 8) The dehumidifier according to claim 8, wherein the sensed parameter comprises the humidity of the ambient air. ### Claim 11 (depends on 8) The dehumidifier according to claim 8, wherein the sensed parameter comprises refrigerant temperature. ### Claim 12 (depends on 8) The dehumidifier according to claim 8, wherein the sensed parameter comprises temperature of air that has passed through the evaporator coil. ### Claim 13 (depends on 12) The dehumidifier according to claim 12, wherein the predetermined range has a threshold of 32 degrees Fahrenheit. ### Claim 14 (depends on 1) The dehumidifier according to claim 1, wherein said airflow path has a fifth segment passing ambient air to said condenser coil, and comprising a second bypass door selectively positionable to variably control airflow along the fifth segment. ### Claim 15 (depends on 14) The dehumidifier according to claim 14, wherein the fifth segment of the airflow path is in parallel with the second segment of the airflow path. ### Claim 16 In a dehumidifier comprising a cabinet; a compressor in the cabinet for delivering hot compressed refrigerant; a condenser coil in the cabinet and receiving refrigerant from the compressor and condensing same; an expansion device in the cabinet and receiving refrigerant from the condenser coil and expanding same; an evaporator coil in the cabinet and receiving refrigerant from the expansion device and evaporating same, and delivering the refrigerant to the compressor, the refrigerant being circulated from the compressor to the condenser coil to the expansion device to the evaporator coil and back to the compressor in a refrigeration cycle; the cabinet having an airflow path therethrough comprising a first segment passing ambient air through a heat exchanger to the evaporator coil, a second segment passing air from the evaporator coil to the condenser coil, a third segment discharging air from the condenser coil, a fourth segment passing ambient air to the evaporator coil; a method comprising the step of: selectively blocking and allowing airflow along the fourth segment to optimize operation of the dehumidifier. ### Claim 17 (depends on 16) The method according to claim 16, further comprising the step of sensing a parameter and selectively blocking and allowing the airflow along the fourth segment based upon the sensed parameter. ### Claim 18 (depends on 17) The method according to claim 17, further comprising the step of operating a bypass door to selectively block and allow the airflow along the fourth segment. ### Claim 19 (depends on 18) The method according to claim 18, further comprising the step of operating a controller to actuate the bypass door. ### Claim 20 (depends on 19) The method according to claim 19, further comprising the step of operating the controller to compare the sensed parameter to a predetermined range and then operating the bypass door to block the airflow along the fourth segment if the parameter is outside of the predetermined range. ### Claim 21 A dehumidification system comprising: a dehumidifier comprising a cabinet; a compressor in the cabinet for delivering hot compressed refrigerant; a condenser coil in the cabinet and receiving refrigerant from the compressor and condensing same; an expansion device in the cabinet and receiving refrigerant from the condenser coil and expanding same; an evaporator coil in the cabinet and receiving refrigerant from the expansion device and evaporating same, and delivering the refrigerant to the compressor; the refrigerant being circulated from the compressor to the condenser coil to the expansion device to the evaporator coil and back to the compressor in a refrigeration cycle; the cabinet having an airflow path therethrough comprising: a first segment passing ambient air through a heat exchanger to the evaporator coil, a second segment passing air from the evaporator coil to the condenser coil, a third segment discharging air from the condenser coil, a fourth segment passing ambient air to the evaporator coil; and a bypass door selectively positionable to block airflow along the fourth segment and alternately to allow airflow along the fourth segment; an actuator; and a controller configured to selectively actuate the actuator and thereby selectively move the bypass door between the open and closed positions. ### Claim 22 (depends on 21) The system according to claim 21, further comprising a sensor configured to sense a parameter and to communicate the parameter to the controller, wherein the controller is further configured to actuate the actuator based upon the sensed parameter. ### Claim 23 (depends on 22) The system according to claim 22, wherein the controller is configured to actuate the actuator when the sensed parameter is in a predetermined range. ### Claim 24 (depends on 23) The system according to claim 23, wherein the parameter is a characteristic of ambient air. ### Claim 25 (depends on 23) The system according to claim 23, wherein the parameter is a characteristic of air that has passed through the evaporator coil. ### Claim 26 (depends on 23) The system according to claim 23, wherein the parameter is an operational characteristic of the dehumidifier.