Defrost systems and methods for heat pump water heaters
AssigneeRheem Manufacturing Company
InventorsAlex Williams, Piyush Porwal
Life of this patent
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Abstract
A heat pump water heater can include a refrigerant circuit, an evaporator coil in fluid communication with the refrigerant circuit, a fan configured to move air across the evaporator coil, one or more temperature sensors, a heating element located proximate an air flow path between the fan and the evaporator, and a controller. The controller can be configured to receive temperature data from the one or more temperature sensors and, in response to the temperature data, output instructions for the fan to move air across the heating element to the evaporator coil.
Claims20
A heat pump water heater system, comprising:
- a refrigerant circuit;
- an evaporator coil in fluid communication with the refrigerant circuit;
- a fan;
- an ambient air temperature sensor;
- and
- a controller configured to:
- receive temperature data from the ambient air temperature sensor;
- and
- in response to the temperature data, output defrost instructions for:
- the heat pump water heater system to stop heating the water;
- the fan to move ambient air across the evaporator coil after the heat pump water heater system has stopped heating the water and based on the temperature data at a first time indicating that a first temperature of the ambient air is below a first temperature threshold;
- and
- the fan to deactivate based on at least one of expiration of a period of time or the temperature data at a second time after the first time indicating that a second temperature of the ambient air is above a second temperature threshold.
A non-transitory, computer-readable medium having instructions stored thereon that, when executed by one or more processors, causes a heat pump water heater controller to:
- receive temperature data from an ambient air temperature sensor;
- and
- in response to the temperature data, output defrost instructions for:
- a heat pump water heater system to stop heating water;
- a fan to move ambient air across an evaporator coil after the heat pump water heater system has stopped heating the water and based on the temperature data at a first time indicating that a first temperature of the ambient air is below a first temperature threshold;
- and
- the fan to deactivate based on at least one of expiration of a period of time or the temperature data at a second time after the first time indicating that a second temperature of the ambient air is above a second temperature threshold.
A method for operating a heat pump water heater system, the method comprising:
- receiving, by processing circuitry of a heat pump water heater system, temperature data from an ambient air temperature sensor;
- and
- in response to the temperature data, outputting, by the processing circuitry, defrost instructions for:
- the heat pump water heater system to stop heating water;
- a fan to move ambient air across an evaporator coil after the heat pump water heater system has stopped heating the water and based on the temperature data at a first time indicating that a first temperature of the ambient air is below a first temperature threshold;
- and
- the fan to deactivate based on at least one of expiration of a period of time or the temperature data at a second time after the first time indicating that a second temperature of the ambient air is above a second temperature threshold.
Dependencies are inferred from the claim text.