A fluid heating device comprising a heat pump and an electric heating element can include a system and method that can receive current data from a current sensor and temperature data from a temperature sensor, determine whether the current is greater than or equal to a threshold current and whether the temperature is greater than or equal to a threshold temperature, and output a control signal to heat the fluid using the heat pump only or the electric heating element only based on the current data and the temperature data.

A fluid heating device comprising a heat pump and an electric heating element can include a system and method that can receive current data from a current sensor and temperature data from a temperature sensor, determine whether the current is greater than or equal to a threshold current and whether the temperature is greater than or equal to a threshold temperature, and output a control signal to heat the fluid using the heat pump only or the electric heating element only based on the current data and the temperature data.

Air heating and potable water systems have a thermostat with a computer processing unit (CPU), a hot water heater, a hydronic air handler, and a primary pump controlling flow of hot water from the water heater into the hydronic air handler, which has a hydronic coil, a blower, and a first control panel having a CPU in operative communicates with the thermostat. The hydronic coil receives hot water from the water heater to warm air passing over the hydronic coil. The primary pump is in operative communication with the first control panel and an indicator of hot water flow. The indicator of hot water flow is in operative communication with either the thermostat or the first control panel, and any CPU in the system stores a priority instruction, which upon an indication of hot water flow deactivates or delays activation of the primary pump for a predetermined period of time.

Air heating and potable water systems have a thermostat with a computer processing unit (CPU), a hot water heater, a hydronic air handler, and a primary pump controlling flow of hot water from the water heater into the hydronic air handler, which has a hydronic coil, a blower, and a first control panel having a CPU in operative communicates with the thermostat. The hydronic coil receives hot water from the water heater to warm air passing over the hydronic coil. The primary pump is in operative communication with the first control panel and an indicator of hot water flow. The indicator of hot water flow is in operative communication with either the thermostat or the first control panel, and any CPU in the system stores a priority instruction, which upon an indication of hot water flow deactivates or delays activation of the primary pump for a predetermined period of time.

Air recirculation systems for heat pumps are disclosed. The air recirculation systems include a heat pump subsystem and a recirculation subsystem. The recirculation subsystem can include one or more arms that direct cool, dehumidified air flowing from the heat pump subsystems back to air inlets. The recirculation subsystems can transition from open to closed configurations either manually or via motors. The air recirculation systems can include a controller that outputs a control signal to the motors to open or close the recirculation subsystems. The control signals can be based on temperature data, current data, and the like.

An air source heat pump system includes at least one heat pump sub-system and at least one water tank. Each heat pump sub-system includes a refrigerant circulation path and a water supply circulation path. The refrigeration circulation path includes a compressor, a first heat exchanger, a first throttling device, and an evaporator that are sequentially connected to one another. The water supply circulation path includes a first supply pipe, a second supply pipe, a return pipe, and a waterway control valve. The first supply pipe and the second supply pipe are each communicated with an end of the first heat exchanger through the waterway control valve, and the return pipe is communicated with another end of the first heat exchanger. The return pipe is communicated with a water inlet of a corresponding water tank, and the second supply pipe is communicated with a water outlet of the corresponding water tank.

An air source heat pump system includes at least one heat pump sub-system and at least one water tank. Each heat pump sub-system includes a refrigerant circulation path and a water supply circulation path. The refrigeration circulation path includes a compressor, a first heat exchanger, a first throttling device, and an evaporator that are sequentially connected to one another. The water supply circulation path includes a first supply pipe, a second supply pipe, a return pipe, and a waterway control valve. The first supply pipe and the second supply pipe are each communicated with an end of the first heat exchanger through the waterway control valve, and the return pipe is communicated with another end of the first heat exchanger. The return pipe is communicated with a water inlet of a corresponding water tank, and the second supply pipe is communicated with a water outlet of the corresponding water tank.

Double hybrid heat pumps, systems, and methods of operation that provide increased efficiency in both heating and cooling modes, heated water, and other advantages. The system includes a compressor for compressing low-pressure vapor phase refrigerant to high-pressure vapor phase refrigerant, a refrigerant condensing heat exchanger to heat water and cool the refrigerant to a high-pressure liquid refrigerant, which is provided to a refrigerant cooling heat exchanger in which any remaining high-pressure vapor phase refrigerant is condensed and the high-pressure liquid refrigerant is further cooled. The high-pressure cooled liquid refrigerant is passed through an expansion valve to drop the pressure of the cooled liquid to yield a low-pressure cooled liquid refrigerant or low-pressure cooled two-phase refrigerant. The low-pressure cooled liquid or two-phase refrigerant is then evaporated in a refrigerant evaporating heat exchanger to produce the low-pressure vapor refrigerant that is returned to the compressor.

Double hybrid heat pumps, systems, and methods of operation that provide increased efficiency in both heating and cooling modes, heated water, and other advantages. The system includes a compressor for compressing low-pressure vapor phase refrigerant to high-pressure vapor phase refrigerant, a refrigerant condensing heat exchanger to heat water and cool the refrigerant to a high-pressure liquid refrigerant, which is provided to a refrigerant cooling heat exchanger in which any remaining high-pressure vapor phase refrigerant is condensed and the high-pressure liquid refrigerant is further cooled. The high-pressure cooled liquid refrigerant is passed through an expansion valve to drop the pressure of the cooled liquid to yield a low-pressure cooled liquid refrigerant or low-pressure cooled two-phase refrigerant. The low-pressure cooled liquid or two-phase refrigerant is then evaporated in a refrigerant evaporating heat exchanger to produce the low-pressure vapor refrigerant that is returned to the compressor.

The disclosed technology includes an evaporator having a plurality of sidewalls arranged to define an internal cavity and a top plate covering the internal cavity. At least one of the sidewalls can include a plurality of refrigerant channels such that at least one of the sidewalls can function as a heat exchanger. Each of the refrigerant channels can be attached to a refrigerant inlet and a refrigerant outlet at an angle, such that each refrigerant channel is angled. The angled refrigerant channels can facilitate directing ambient air across the refrigerant channels and fins and to the internal cavity. The angled refrigerant channels can further provide a flow path for accumulated moisture and/or condensate on the exterior surfaces of the refrigerant channels and/or fins to shed, thereby minimizing the potential for freezing.