Abstract: A combination water heating, air conditioning refrigerant system is described. The combined system includes a plurality of independently adjustable electronic expansion valves. The expansion valves can independently modulate the delivery of high-temperature, high-pressure refrigerant to either a water heat exchanger or an outside condenser. A controller can receive input signals, including temperature signals from one or more temperature sensors that indicate the temperature at various locations of the system. The temperature signals include one or more of water temperature signals, ambient air temperature signals, or refrigerant super heat temperatures signals. In response to the input signals, the controller can output control signals to one or more of the plurality of electronic expansion valves.

Abstract: The disclosed technology includes a gas delivery system for controlling a target gas input rate of a fluid heating device. The system can include a sensor configured to measure a temperature of a gas flowing in a gas flow path, a modulating orifice in fluid communication with the gas flow path, and a motor in mechanical communication with the modulating orifice. The system can further include a controller configured to receive temperature data indicative of the temperature of the gas. The controller can determine a target cross-sectional area of the modulating orifice based at least in part on the target gas input rate and the temperature of the gas and, in response, output a signal to the motor to transition the modulating orifice from a first position to a second position having the target cross-sectional area.

Abstract: Devices and methods for controlling a heat pump system are presented. A method may include identifying, by a first device, a signal received from a second device associated with an outdoor portion of the heat pump system, the signal indicating that the heat pump system is performing a defrost operation; reducing, based on the defrost operation, a speed of a fan associated with an indoor portion of the heat pump system; identifying pressure data received from a pressure sensor during the defrost operation, the pressure data indicative of a suction line pressure of the heat pump system; determining, based on the pressure data, that the suction line pressure is below a threshold pressure, the threshold pressure greater than a low-pressure fault threshold; and increasing the speed of the fan based on the determination that the suction line pressure is below the threshold pressure.

Abstract: A liquid dosing system is disclosed and can include a cartridge comprising a reservoir configured to store an additive, an output vessel in fluid communication with the reservoir, and a cartridge outlet in fluid communication with the output vessel. The liquid dosing system can include a housing that includes a water passage configured to direct water though the liquid dosing system and a receiving portion configured to at least partially receive the cartridge when the cartridge is connected to the housing. The receiving portion can include a receiving port in fluid communication with the water passage, and the receiving port can be configured to receive at least some of the additive from the cartridge outlet when the cartridge is connected to the housing. The receiving portion can include a motor configured to engage in mechanical communication with the output vessel when the cartridge is connected to the housing.

Abstract: A heat pump water heater has a tank, a heat source, and a heat pump system. The heat pump system has a refrigerant path, at least a portion of which is in thermal communication with the water tank volume so that heat transfers from refrigerant to the water tank volume. A fan causes air to flow through a housing, and another portion of the refrigerant path includes an evaporator in the housing. The fan is within the housing and may further be within a second housing. The first housing may comprise a baffle to direct air flow. The fan may be a variable speed fan in communication with a controller, so that the controller controls the fan speed depending on a temperature of the refrigerant.

Abstract: The disclosed technology includes devices and systems for an economizer of a heating ventilation and air conditioning (HVAC) system. The disclosed technology can include an economizer for an HVAC system comprising a housing, an air inlet extending through a wall of the housing, a sliding door configured to transition between a closed position and an open position, and a controller configured to cause the sliding door to transition between the closed position and the open position based on temperature data. The sliding door can comprise a first portion forming a barrier and a second portion comprising at least one aperture. In the closed position, the first portion can align with the air inlet and substantially prevent ambient air from moving through the air inlet. In the open position, the second portion can align with the air inlet and permit the ambient air to move through the air inlet.

Abstract: Systems and methods for integrating photovoltaic (PV) energy into water heater systems are disclosed. The disclosed technology includes determining whether a current water temperature is less than a first PV heat point that is greater than a normal heat point, and if so, outputting instructions for PV energy to be transferred from a PV system to a heating device of the water heater. If the current water temperature falls below a second PV heat point that is less than the normal heat point, the disclosed technology includes outputting instructions for energy to be transferred from a utility system to the heating device.

Abstract: A noise muffler for an air moving device can include a housing with a housing inlet, a housing outlet, and at least a first foam component and a second foam component. The first foam component and the second foam component are placed within a cavity of the housing and define an air passageway. The first foam component and the second foam component redirect air flow through the cavity in three dimensions in order to muffle noise generated by the air moving device.

Abstract: The present disclosure addresses systems, media, and methods of configuring a heating system comprising a plurality of combustion-type heating devices fluidly coupled to a vent system. Configuring the heating system includes receiving operating pressure data from one or more pressure sensors in a flue of one of combustion-type heating devices and the vent system. The operating pressure data from the one or more pressure sensors is indicative of a pressure at a corresponding location in the vent system. Configuring the heating system further includes comparing the operating pressure data to stored operational pressure data indicative of operational pressure ranges indicative of permissible operating parameters associated with preventing backflow of flue gases into the one of combustion-type heating devices and outputting instructions for a damper to at least partially open or at least partially close based at least in part on the operating pressure data and the stored operational pressure data.

Abstract: A tankless electric water heater system including a heating chamber having an inlet at a first end and an outlet at a second end, a heating element connected to the heating chamber, a first temperature sensor disposed near the first end of the heating chamber, a second temperature sensor disposed near the second end of the heating chamber, a flow sensor configured to detect a flow of water and disposed near the heating chamber, and a controller connected to the first and second temperature sensors, the flow sensor, and the heating element. The controller is configured to have a set point temperature, to detect temperature and flow data from the first and second temperature sensors, and the flow sensor, and to provide as output a power setting to the heating element.

Abstract: Disclosed herein are evaporator assemblies for heat pump systems. The evaporator units can comprise a housing defining an interior chamber, an air inlet and an air outlet. The air inlet and the air outlet can form an air flow path through the interior chamber, and an evaporator unit can be positioned within the interior chamber such that the air flow path contacts the evaporator unit. The air inlet having a semi-circular cross section through which air flows into the interior chamber, the semi-circular cross section having a straight edge and a curved edge. A velocity magnitude of the air flowing from the air inlet into contact with the evaporator unit can deviate less than 0.1 m/s from the average air velocity across the surface area of the evaporator.

Abstract: A heated water recirculation system includes a water heater having a water inlet and a water outlet. The heated water recirculation system further includes a flow detector positioned to detect inflow water flowing into the water heater through the water inlet. The heated water recirculation system also includes a controller configured to control operations of a recirculation pump based on a detection of the inflow water flowing into the water heater through the water inlet. The water heater is configured to provide heated water through the water outlet, and the recirculation pump is configured to circulate the heated water through the heated water recirculation system.

Abstract: The disclosed technology includes a combustion system providing ease of access to components of the combustion system and optimal placement of a burner such that efficient combustion and heat transfer can occur. The combustion system can include an inner tube having a first end and a second end, the second end having a flange with a sensor port, and an outer tube having a first end and a second end. The inner tube can be disposed within the outer tube. The inner tube can have an outer diameter less than an inner diameter of the outer tube, creating a gap between the outer tube and inner tube. An ignitor assembly and a flame sensor assembly can extend through the sensor port and the gap and be positioned proximate a burner.

Abstract: A liquid slug reduction and charge compensator device for use in air conditioning and heat pump systems includes a housing having a cavity. The housing includes an inlet port providing an entry path into the cavity and an outlet port providing an exit path from the cavity. The housing further includes a liquid line port providing a refrigerant pathway into and out of the cavity. The liquid slug reduction and charge compensator device further includes a flash tube extending through the cavity and providing a passageway through the cavity such that a hot gas refrigerant that enters the cavity through the inlet port causes a liquid refrigerant that enters the flash tube to evaporate.

Abstract: A hybrid heating system having a heat recovery apparatus in fluid communication with a heat pump and a furnace is provided. The apparatus recovers heat from flue gas discharged from the furnace and transfers the recovered heat to a stream of refrigerant in the heat pump. The apparatus includes a shell disposed in fluid communication with the furnace and tubes disposed in fluid communication with the shell and the heat pump. The system includes valves for regulating access between the apparatus and the stream of the refrigerant in the heat pump, and a control unit in communication with the valves to regulate access between the apparatus and the heat pump during a heating mode based on operating parameters of the system.

Abstract: A leakage mitigation system to trigger a preventive action against detected leakage from a liquid enclosure, includes a leakage detection device disposed along base of the liquid enclosure. The system includes an absorbent that actuates the leakage detection device from a first state to a second state based on a volume of liquid leaked from the liquid enclosure. The device includes a valve coupled to an inlet pipe of the liquid enclosure and configured to allow flow of liquid through the inlet pipe in an open condition thereof and restrict flow of liquid through the inlet pipe in a closed condition thereof. The system further includes a shut-off actuator coupled to the valve and configured to actuate the valve from the open condition to the closed condition in response to the device being actuated from the first state to the second state.

Abstract: A system for coating an interior surface of a heat exchanger includes a tank for storing the coating solution, a pump, a source line for supplying the coating solution to the heat exchanger, and a return line for returning the remainder of the coating solution to the tank. The system can include a pre-treatment line for supplying a pre-treatment solution to the heat exchanger and a water line for supplying water to the heat exchanger. An air compressor can be coupled to the heat exchanger to force the coating solution, the pre-treatment solution, or the water from the heat exchanger.

Abstract: A heat pump water heater can include a water tank and a refrigerant circuit that can be in fluid communication with an evaporator coil, a condenser coil, and a compressor. The heat pump water heater can include a fan configured to move air across the evaporator coil, a temperature sensor, and a controller. The controller can be configured to receive temperature data from the temperature sensor and, in response to the temperature data indicating a temperature less than a predetermined temperature threshold, output instructions for the compressor to deactivate and the fan to move air across the evaporator coil.