Boosted air source heat pump
AssigneeShaw Engineering Associates, LLC
InventorsDavid N. Shaw, David S. Fishman
Life of this patent
Estimating the term…
Abstract
A heat pump system is presented having a primary compressor, a booster compressor, a multi-step thermostat, an indoor coil, an outdoor coil, a refrigerant flow conduit connecting these elements is a closed loop system, and at least one pressure sensor positioned to always sense the refrigerant system low side pressure, which is commensurate with outdoor ambient air temperature in all heating modes of operation. The pressure sensor functions as an override and safety control to prevent or permit operation of the compressors, and also other system components, depending on outside air temperature. The primary compressor is preferably a multi-capacity compressor. A defrost energy transfer fluid is used in a defrost cycle.
Claims31
A heat pump system including:
- a primary compressor;
- a booster compressor;
- a refrigerant conduit system, said primary compressor and said booster compressor being in series in said refrigerant conduit system;
- a control panel, said control panel being connected between a multi-step thermostat and said primary and booster compressors, said control panel receiving signals from the multi-step thermostat and delivering power to operate said primary compressor and said booster compressor in a predetermined sequence in response to steps of the thermostat;
- and
- at least one pressure sensor connected to said refrigerant conduit system for sensing refrigerant pressure at approximately the refrigerant low pressure side to generate signals to prevent or permit operation of said primary compressor or said booster compressor as a function of outdoor ambient temperature.
A beat pump system including:
- a multi-capacity primary compressor;
- a booster compressor;
- a refrigerant conduit system, said primary compressor and said booster compressor being in series in said refrigerant conduit system;
- a source of backup heat in said heat pump system;
- a control panel, said control panel being connected between a multi-step thermostat and said primary and booster compressors, said control panel receiving signals from the multi-step thermostat and delivering power to operate said primary compressor and said booster compressor in a predetermined sequence in response to steps of the thermostat;
- and
- at least one pressure sensor connected to said refrigerant conduit system for sensing refrigerant pressure at approximately the refrigerant low pressure side to generate signals to prevent or permit operation of said primary compressor, said booster compressor, and said backup heat as a function of outdoor ambient temperature.
A heat pump system including:
- a multi-capacity primary compressor;
- a booster compressor;
- a refrigerant conduit system, said primary compressor and said booster compressor being in series in said refrigerant conduit system;
- a source of backup heat in said heat pump system;
- a control panel, said control panel being connected between a multi-step thermostat and said primary and booster compressors, said control panel receiving signals from the multi-step thermostat and delivering power to operate said primary compressor and said booster compressor in a predetermined sequence in response to steps of the thermostat;
- and
- a plurality of pressure sensors connected to said refrigerant conduit system for sensing refrigerant pressure at approximately the refrigerant low pressure side to generate signals to prevent or permit operation of said primary compressor, said booster compressor, said economizer, and said backup heat as a function of outdoor ambient temperature.
A method of operating a heat pump system having a primary compressor, a booster compressor, and a multi-step thermostat, including the steps of:
- a) permitting operation of said primary compressor when called for by a first step of said thermostat;
- b) permitting operation of said booster compressor when called for by a second step of said thermostat;
- c) sensing refrigerant pressure at approximately the refrigerant system low side pressure, said pressure being commensurate with outdoor ambient air temperature;
- d) preventing operation of said booster compressor, even if called for by the thermostat, when refrigerant system low side pressure is higher than a predetermined level;
- and
- e) preventing operation of said booster compressor and said primary compressor, even if called for by the thermostat, when refrigerant system low side pressure is lower than a predetermined level.
A method of operating a heat pump system having a multi-capacity primary compressor, a booster compressor, and a multi-step thermostat, including the steps of:
- a) permitting partial capacity operation of said primary compressor when called for by a first step of said thermostat;
- b) permitting full capacity operation of said primary compressor when called for by a second step of said thermostat;
- c) permitting operation of said booster compressor when called for by a third step of said thermostat;
- d) sensing refrigerant pressure at approximately the refrigerant system low aide pressure, said pressure being commensurate with outdoor ambient air temperature;
- e) preventing partial capacity operation of said primary compressor, even if called for by said thermostat, and requiring full capacity operation of said primary compressor when outdoor ambient temperature is too cold for safe partial capacity operation of said primary compressor
- f) preventing operation of said booster compressor, even if called for by the thermostat, when refrigerant system low side pressure is higher than a predetermined level;
- and
- g) preventing operation of said booster compressor and said primary compressor, even if called for by the thermostat, when refrigerant system low side pressure is lower than a predetermined level.
A method of operating a heat pump system having a multi-capacity primary compressor, a booster compressor, an economizer, and a multi-step thermostat, including the steps of:
- of:
- a) permitting full capacity operation of said primary compressor when called for by a first step of said thermostat;
- b) permitting operation of said booster compressor when called for by a second step of said thermostat;
- c) permitting operation of said economizer when called for by a third step of said thermostat;
- d) sensing refrigerant pressure at approximately the refrigerant system low side pressure, said pressure being commensurate with outdoor ambient air temperature;
- e) preventing operation of said booster compressor, even if called for by the thermostat, when refrigerant system low side pressure is higher than a predetermined level;
- f) preventing operation of said economizer when refrigerant system low side pressure is higher than a predetermined level;
- and
- g) preventing operation of said booster compressor and said primary compressor, even if called for by the thermostat, when refrigerant system low side pressure is lower than a predetermined level.
A method of operating a heat pump system having a multi-capacity primary compressor, a booster compressor, an economizer, a source of backup heat, and a multi-step thermostat, including the steps of:
- a) permitting full capacity operation of said primary compressor when called for by a first step of said thermostat;
- b) permitting operation of said booster compressor and said economizer when called for by a second step of said thermostat;
- c) permitting operation of said source of backup heat when called for by a third step of said thermostat;
- d) sensing refrigerant pressure at approximately the refrigerant system low side pressure, said pressure being commensurate with outdoor ambient air temperature;
- e) preventing operation of said booster compressor, even if called for by the thermostat, when refrigerant system low side pressure is higher than a predetermined level;
- f) preventing operation of said economizer when refrigerant system low side pressure is higher than a predetermined level;
- g) preventing operation of said source of backup heat when refrigerant low side pressure is higher than a predetermined level;
- and
- h) preventing operation of said booster compressor and said primary compressor, even if called for by the thermostat, when refrigerant system low side pressure is lower than a predetermined level.
A heat pump system operating in the cooling mode, said system including:
- a primary compressor;
- a booster compressor;
- a refrigerant conduit system, said primary compressor and said booster compressor being in series in said refrigerant conduit system;
- a control panel, said control panel being connected between a multi-step thermostat and said primary and booster compressors, said control panel receiving signals from the multi-step thermostat and delivering power to operate only said primary compressor in a predetermined sequence in response to steps of the thermostat;
- and
- at least one pressure sensor connected to said refrigerant conduit system for sensing refrigerant pressure at approximately the refrigerant low pressure side to generate signals to prevent or permit operation of said primary compressor as a function of outdoor ambient temperature.
A method of operating a heat pump system in a cooling mode, said system having a primary compressor, a booster compressor, and a multi-step thermostat, including the steps of:
- a) operating only said primary compressor;
- b) sensing refrigerant pressure at approximately the refrigerant system low side pressure, said pressure being commensurate with outdoor ambient air temperature;
- and
- c) preventing operation of said primary compressor when refrigerant system low side pressure falls to a predetermined point.
A defrost system for a heat pump, said heat pump having an outdoor coil, an indoor coil, at least one compressor, and a conduit system for circulating refrigerant to said compressor, said outdoor coil and said indoor coil, the defrost system including;
- a) a bypass conduit for bypassing refrigerant around said indoor coil,
- b) a heat exchanger in said bypass conduit;
- c) a defrost energy transfer fluid supplied to said heat exchanger for imparting energy to said refrigerant in said heat exchanger;
- d) said refrigerant being delivered from said heat exchanger to said compressor for compression and then to said outdoor coil.
A method of defrosting an outdoor coil in a heat pump system, the heat pump system having an outdoor coil, an indoor coil, at least one compressor, and a conduit system for circulating refrigerant to said compressor, said outdoor coil and said indoor coil, including the steps of;
- a) bypassing refrigerant around said indoor coil;
- b) delivering a defrost energy transfer fluid in heat exchange relationship with said bypassed refrigerant to impart energy to said bypassed refrigerant;
- c) delivering the refrigerant from the heat exchanger to said at least one compressor;
- d) compressing said refrigerant in said compressor;
- and
- e) delivering said refrigerant from said compressor to said outdoor coil.
Dependencies are inferred from the claim text.