Abstract: The disclosed technology includes a controller for a cascade boiler system having both condensing and non-condensing boilers. The controller can receive supply water temperature data and return water temperature data to determine a current temperature differential in the system. The controller can determine a current load demand value using the current temperature differential and a set point temperature. If the current load demand value is less than or equal to a first load demand threshold, the controller can output a control signal for a condensing boiler to transition to a heating mode. If the current load demand value is greater than a second load demand threshold, the controller can output a control signal for a non-condensing boiler to transition to a heating mode.

Abstract: The disclosed technology includes a variable refrigerant flow (VRF) conditioning system including a single outdoor unit and a VRF path extending between the single outdoor unit and a plurality of terminals. The plurality of terminals can include a first terminal configured to condition air of an interior room and a second terminal configured to heat or cool a liquid. The VRF system can provide heating or cooling of air in different rooms or zones within a building or home while also providing heating or cooling of water. In response to a demand for heating or cooling at each terminal, the VRF system can vary the supply of refrigerant to each terminal, such that efficient and precise temperature regulation of air and liquid can be provided.

Abstract: The disclosed technology includes a fluid heating device that can include a heating chamber in communication with a heating element, and an ultrasonic transducer in communication with the heating chamber and for transmitting ultrasonic sound waves. The disclosed technology includes an ultrasonic transducer system that includes an assembly configured to attach to a fluid heating device, and an ultrasonic transducer affixed to the assembly. The disclosed technology also includes a method for ultrasonic cleaning within a fluid heating device that can include a controller configured to receive flow data from a flow sensor; based on the flow data, determine that fluid is flowing through a heating chamber; and output instructions for an ultrasonic transducer to output ultrasonic sound waves.

Abstract: A screen cover for attaching to an open end of a conduit of a water heater is provided. The screen cover includes a first diametric portion having a first diameter and a second diametric portion having a second diameter. The first diameter is greater than the second diameter. The first and second diametric portions are coaxially aligned and configured to allow flow of air or gas therethrough. The screen cover includes a shoulder portion defined between the first diametric portion and the second diametric portion. The screen cover further includes a mesh disposed at a first opening of the first diametric portion. The mesh prevents entry of external objects into the water heater through the open end of the conduit.

Abstract: 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.

Abstract: A hose nozzle assembly which is capable of heating water comprising an internal heating chamber with at least one heating element. The hose nozzle assembly is able to heat water from a common garden hose with the ability to control both flow rates and temperature.

Abstract: In an electric water heater having adjustable set point and differential temperatures, upper and lower heating elements, and associated temperature sensors respectively operative to sense upper and lower tank water temperatures, a specially designed control system is provided for controlling the heating elements. The control system is operative to prevent dry firing of the heating elements by measuring temperatures over time with the temperature sensors.

Abstract: The disclosed technology includes a device for extending the turndown ratio of a gas-fired burner system. The device can comprise a variable area device configured reduce the amount of fuel and air passed to the burner during low output conditions by adjusting the cross-sectional area of the passage between the blower and the burner. The variable area device can be controlled by an actuator that adjusts the position of the variable area device. The actuator can be manually controlled, mechanically controlled, or electronically controlled.

Abstract: A control system can provide a linear behavior of airflow as a function of damper position of each zone damper in an HVAC system. The control system incrementally closes each zone damper from a fully open position to a fully closed position, and records static pressure measurements with each change in damper position. Then, using a mathematical model that is derived from the second fan law, a correction is calculated for each damper position of each zone damper based on the recorded static pressure measurements to provide corrected damper positions at which the airflow through the zone damper exhibits a linear behavior. The corrected damper positions are stored and used during an operational cycle of the HVAC system to obtain a precise airflow through the zone dampers.

Abstract: The disclosed technology includes a cleaning device for cleaning personal care tools, such as toothbrushes and shaving razors. The cleaning device can include a heating element configured to heat cleaning fluid received by the cleaning device and a high pressure nozzle configured to output heated cleaning fluid into the cleaning chamber.

Abstract: The disclosed technology includes a non-powered valve assembly having a valve, an actuating system, and a trigger. The trigger can be in mechanical communication with the actuating system and the actuating system can be in mechanical communication with the valve. The trigger can be positioned such that the trigger can interact with liquid resulting from a leak in a plumbing assembly. Upon interaction with liquid, the trigger can dissolve or expand, causing the actuating system to be activated and the valve to transition from the open position to a closed position. In the closed position, the valve can restrict the passage of liquid through the plumbing assembly such that the leak can be mitigated.

Abstract: The metal tank portion of an electric water heater is protected against corrosion utilizing a corrosion protection system that detects a voltage potential between the sheath portion of a tank water-immersed electric heating element and the tank. In one embodiment of the corrosion protection system the sensed sheath/tank potential is utilized to enable a user of the water heater to accurately gauge the necessity of replacing a sacrificial anode extending into the tank. In another corrosion protection system, the sensed sheath/tank potential is utilized to provide impressed current cathodic protection of the tank and also to prevent dry firing of the electric water heater.

Abstract: The disclosed technology includes an on-demand water heater which uses an electric heat source to heat the water. The on-demand water heater can have a low fluid capacity heating chamber which has an inlet and an outlet, an electric heat source for heating the water, and a controller to control the electric heat source and maintain the temperature of the water at a predetermined temperature setting. The on-demand water heater can be powered by a direct current power source. The on-demand water heater can also utilize a solar thermal system to provide additional heat to the water.

Abstract: Systems and methods for dynamic boiler control are disclosed. The system can receive flue gas data from a flue gas sensor and can receive blower data associated with a blower of the boiler. The system can determine, based at least in part on the blower data, a current fire status of the boiler and can provide one or more fire-status-specific parameters based on the current fire status of the boiler. The system can compare the flue gas data to a target flue gas value, and in response to determining that the flue gas data is less than the target flue gas value, the system can execute one or more boiler operation rules using the one or more fire-status-specific parameters. The system can output instructions for adjustment of an air-fuel ratio of the boiler based on the boiler operation rules and the one or more fire-status-specific parameters.

Abstract: A grille assembly for an air handling unit is provided. The grille assembly includes a plurality of first wires aligned in a first plane perpendicular to a direction of flow of air and a plurality of second wires aligned in a second plane perpendicular to the direction of flow of air. The plurality of first wires and the plurality of second wires together form a staggered structure to at least partly enclose an air passage opening of the air handling unit. The second plane is parallel to the first plane and separated by an offset distance along a third plane parallel to the direction of flow of air.

Abstract: A water heater monitoring and notification method includes determining, by a controller of a water heater system, a deviation of a duration of a pre-purge operation from a pre-purge duration average value. The method further includes determining, by the controller of the water heater system, a deviation of a flame current from a flame current average value and determining, by the controller of the water heater system, a deviation of a pulse-width-modulation (PWM) parameter from a PWM parameter average value. The method also includes providing a notification related to a combustion system of the water heater system based on at least the deviation of the duration of the pre-purge operation from the pre-purge duration average value, the deviation of the flame current from the flame current average value, and the deviation of the PWM parameter from the PWM parameter average value.

Abstract: A compression refrigeration system includes a switch to select between a plurality of operation modes of a metering device that controls a rate of flow of a refrigerant to an evaporator of the compression refrigeration system. Each operation mode is associated with a respective refrigerant. Further, the compression refrigeration system includes a reference database that comprises pressure-temperature data associated with a plurality of refrigerants. Furthermore, the compression refrigeration system includes a valve adjustment engine that is communicatively coupled to the switch and the reference database. The valve adjustment engine controls the metering device based on an operation mode of the metering device that is selected using the switch. The operation mode is selected based on a refrigerant with which the compression refrigeration system is currently charged.

Abstract: System and methods for controlling operating state of a heat transfer system are disclosed herein. The heat transfer system can include temperature sensor positioned at the fluid inlet line and the fluid outlet line and a heat exchanger between the fluid inlet line and the fluid outlet line. The heat transfer system can include a processor communicatively coupled to the first temperature sensor and the second temperature sensor. The processor can determine an inlet temperature of water flowing in the fluid inlet line and outlet temperature of water flowing in the fluid outlet line and can determine a delta temperature based on difference between the inlet temperature and the outlet temperature. Based on the inlet temperature and the delta temperature, the processor can determine an operating state of the heat transfer system.

Abstract: The disclosed technology includes systems and methods for reducing temperature overshoot of a heating, ventilation, and air conditioning (HVAC) system. The disclosed technology can include a thermostat having a temperature sensor and a controller. The controller can be configured to receive temperature data from the temperature sensor, determine whether a time since the heating cycle of the HVAC unit began is greater than or equal to a predetermined amount of time, and determine whether a current temperature is less than or equal to a low threshold temperature, the low threshold temperature being less than a target temperature. If the current temperature is less than or equal to the low threshold temperature, the controller can determine whether a capacity of the HVAC unit at the end of the heating cycle is greater than a threshold capacity and adjust a response setting of the thermostat by a predetermined adjustment amount.

Abstract: A water heater includes a tank assembly that defines an insulation cavity between an inner storage tank and an outer jacket. The water heater includes a bottom pad that supports the tank assembly thereon. The bottom pad is disposed in a bottom pan. Gaskets are disposed between the bottom pad and the bottom pan of the water heater. The bottom pad and at least one of the gaskets include apertures that are configured to internally route a leak sensor assembly of the water heater from the bottom pan to a controller of the water heater through the insulation cavity while preventing a leak of insulation material from the insulation cavity to the bottom pan. The water heater also includes a mounting bracket that is coupled to the inner storage tank to securely hold and route a portion of the leak sensor assembly disposed in the insulation cavity to the controller.