Defrost systems and methods for heat pump water heaters
AssigneeRheem Manufacturing Company
InventorsAlex Williams, Piyush Porwal
Life of this patent
Estimating the term…
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.
Claims16
A heat pump water heater system, comprising:
- a refrigerant circuit;
- an evaporator coil in fluid communication with the refrigerant circuit;
- a fan configured to move air in a first direction through an inlet then across the evaporator coil and then trough an outlet when the heat pump water heater system is heating water and move air in a second direction through the outlet then across the evaporator coil and then through the inlet when operating in a defrost mode;
- one or more temperature sensors;
- a heating element located proximate an air flow path between the fan and the evaporator coil;
- and
- a controller configured to:
- receive temperature data from the one or more temperature sensors;
- and
- in response to the temperature data, output defrost instructions for:
- the heating element to activate;
- the heat pump water heater system to stop heating the water;
- and
- the fan to change from a configuration to move air in the first direction to a configuration to move air in the second direction across the heating element then the evaporator coil to defrost the evaporator coil using the air blown by the fan and then through the inlet, wherein the heating element is configured to heat the air blown by the fan.
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 one or more temperature sensors;
- and
- in response to determining, based at least on part on the temperature data, that frost accumulation on an evaporator coil of a heat pump water heater is likely:
- output first instructions for the heat pump water heater to stop heating water;
- output second instructions for a heating element of the heat pump water heater to activate;
- and
- output third instructions for a fan of the heat pump water heater to change from a first configuration to move air in a first direction through an inlet then across the evaporator coil and then trough an outlet when the heat pump water heater is heating water to a second configuration to move air in a second direction through the outlet then across the evaporator coil to defrost the evaporator coil and then through the inlet, wherein the heating element heats the air blown by the fan.
A method for operating a heat pump water heater system, the method comprising:
- positioning a heating element proximate an air flow path between a fan and an evaporator coil of the heat pump water heater system;
- receiving temperature data from one or more temperature sensors of the heat pump water heater system;
- and
- causing, based on the temperature data, the fan to reverse direction from a first direction that moves air through an inlet then across the evaporator coil and then trough an outlet when the heat pump water heater system is heating the water to a second direction through the outlet then across the evaporator coil to defrost the evaporator coil and then through the inlet, wherein the heating element heats the air blown by the fan.
Dependencies are inferred from the claim text.