Abstract: An HVAC system includes an indoor heat-exchange coil disposed between a supply air duct and a return air duct. A damper is disposed in a re-circulation duct and is moveable between an open position and a closed position. A controller is configured to determine if the HVAC system is operating in a heating mode or an air-conditioning mode. Responsive to a determination that the HVAC system is operating in the air-conditioning mode, the controller is configured to determine if the variable-speed indoor circulation fan is operating at a minimum speed and if the relative humidity measured by the humidity sensor is above a pre-determined threshold. Responsive to a determination that the variable-speed indoor circulation fan is operating at the minimum speed and the relative humidity of the enclosed space is above the pre-determined threshold, the controller signals the damper to move to the open position.

Abstract: A defrost method for a heat pump system includes running the heat pump system in a heating mode to provide heat to an enclosed space and determining if an outdoor temperature is less than an outdoor threshold temperature. Responsive to a determination that the outdoor temperature is below the outdoor threshold temperature, determining if a calibration state has been previously run. Responsive to a determination that the calibration state has not been previously run, running the heat pump system in the calibration state. Responsive to a determination that the calibration state has been previously run, determining if a temperature difference between a temperature of an evaporator coil of the heat pump system and the outdoor temperature exceeds a temperature threshold value. Responsive to a determination that the temperature difference between the evaporator coil and the outdoor temperature is greater than the temperature threshold value, running the heat pump system in a defrost state.

Abstract: A device configured to operate a Heating, Ventilation, and Air Conditioning (HVAC) system and to receive an audio signal from a microphone while operating HVAC system. The device is further configured to generate a representation of the audio signal, to compare one or more audio signatures to the representation of the audio signal, and to determine that an audio signature from among the one or more audio signatures is not present within the representation of the audio signal. The device is further configured to determine a fault type that is associated with the audio signature that is not present within the representation of the audio signal, to identify a component identifier for a component of the HVAC system that is associated with fault type, and to output the component identifier.

Abstract: An apparatus includes a high side heat exchanger, a second heat exchanger, a load, a variable speed compressor, and a three-way valve. The high side heat exchanger removes heat from a refrigerant. The second heat exchanger removes heat from the refrigerant. The load uses the refrigerant to remove heat from a space proximate the load. The variable speed compressor compresses the refrigerant from the load and directs the compressed refrigerant to the high side heat exchanger. The three-way valve, when operating in a first mode, directs the refrigerant from the high side heat exchanger to the load and when operating in a second mode, directs the refrigerant from the high side heat exchanger to the second heat exchanger.

Abstract: An apparatus includes a high side heat exchanger, a second heat exchanger, a load, a variable speed compressor, and a three-way valve. The high side heat exchanger removes heat from a refrigerant. The second heat exchanger removes heat from the refrigerant. The load uses the refrigerant to remove heat from a space proximate the load. The variable speed compressor compresses the refrigerant from the load and directs the compressed refrigerant to the high side heat exchanger. The three-way valve, when operating in a first mode, directs the refrigerant from the high side heat exchanger to the load and when operating in a second mode, directs the refrigerant from the high side heat exchanger to the second heat exchanger.

Abstract: A method of initiating a defrost cycle using a controller of a heat pump system includes measuring a temperature of an evaporator coil and determining whether the temperature of the evaporator coil is less than a freezing temperature. Responsive to a determination that the temperature of the evaporator coil is less than the freezing temperature, determining whether a current dew point temperature of air is greater than the temperature of the evaporator coil. Responsive to a determination that the current dew point temperature of air is greater than the temperature of the evaporator coil, calculating a frost-collection rate. Determining whether the frost-collection rate is greater than a frost-collection-rate threshold, and, responsive to a determination that the frost-collection rate is greater than the frost-collection-rate threshold, initiating a defrost cycle.

Abstract: An HVAC system includes a pressure sensor is disposed in a suction line between a compressor and an indoor heat-exchange coil. The pressure sensor is electrically coupled to a compressor controller. An HVAC controller is electrically coupled to the compressor controller. The HVAC controller is configured to transmit a signal to the compressor controller to activate and de-activate the compressor. The compressor controller is configured to receive a signal from the HVAC controller to activate the compressor, determine a start speed of the compressor, monitor a run time of the compressor, and modulate a speed of the compressor.

Abstract: A refrigerant detector testing system according to aspects of the disclosure includes a metering orifice formed in a suction line that is disposed between an evaporator coil and a compressor, a valve fluidly coupled to the metering orifice, a connecting tube fluidly coupled to the valve on a side opposite the metering orifice, a mixing device having an input orifice fluidly coupled to the connecting tube. In some embodiments, the mixing device includes an air intake disposed proximate the input orifice, a throttling portion downstream of the input orifice and the air intake, the throttling portion having a reduced cross-sectional area, and a diffuser section positioned downstream of the throttling portion, the diffuser section having an output orifice. According to aspects of the disclosure, a refrigerant detector fluidly exposed to the output orifice.

Abstract: A defrost method for a heat pump system includes running the heat pump system in a heating mode to provide heat to an enclosed space and determining if an outdoor temperature is less than an outdoor threshold temperature. Responsive to a determination that the outdoor temperature is below the outdoor threshold temperature, determining if a calibration state has been previously run. Responsive to a determination that the calibration state has not been previously run, running the heat pump system in the calibration state. Responsive to a determination that the calibration state has been previously run, determining if a temperature difference between a temperature of an evaporator coil of the heat pump system and the outdoor temperature exceeds a temperature threshold value. Responsive to a determination that the temperature difference between the evaporator coil and the outdoor temperature is greater than the temperature threshold value, running the heat pump system in a defrost state.

Abstract: An HVAC system includes an indoor heat-exchange coil disposed between a supply air duct and a return air duct. A damper is disposed in a re-circulation duct and is moveable between an open position and a closed position. A controller is configured to determine if the HVAC system is operating in a heating mode or an air-conditioning mode. Responsive to a determination that the HVAC system is operating in the air-conditioning mode, the controller is configured to determine if the variable-speed indoor circulation fan is operating at a minimum speed and if the relative humidity measured by the humidity sensor is above a pre-determined threshold. Responsive to a determination that the variable-speed indoor circulation fan is operating at the minimum speed and the relative humidity of the enclosed space is above the pre-determined threshold, the controller signals the damper to move to the open position.

Abstract: A method of mitigating liquid-refrigerant migration includes comparing a requested compressor speed of a variable-speed compressor to a pre-defined threshold and, responsive to a determination that the requested compressor speed is greater than the pre-defined threshold, operating the variable-speed compressor at a first compressor speed that is less than the requested compressor speed.

Abstract: An HVAC system includes a heating element, a discharge air temperature sensor, and a return air temperature sensor. A controller of the HVAC system determines that the HVAC system has been operating in the heating mode for at least a predefined amount of time. The controller receives measurements of the discharge air temperature and the return air temperature. A temperature rise value is determined using the discharge air temperature and return air temperature. If the temperature rise value is less than a predefined minimum threshold value, the controller determines that a first fault of the HVAC system is detected and provides a corresponding alert. If the temperature rise value is greater than a predefined maximum threshold value, the controller determines that a second fault of the HVAC system is detected and provides a corresponding alert.

Abstract: An HVAC system includes a heating element, a discharge air temperature sensor, and a return air temperature sensor. A controller of the HVAC system determines that the HVAC system has been operating in the heating mode for at least a predefined amount of time. The controller receives measurements of the discharge air temperature and the return air temperature. A temperature rise value is determined using the discharge air temperature and return air temperature. If the temperature rise value is less than a predefined minimum threshold value, the controller determines that a first fault of the HVAC system is detected and provides a corresponding alert. If the temperature rise value is greater than a predefined maximum threshold value, the controller determines that a second fault of the HVAC system is detected and provides a corresponding alert.

Abstract: An HVAC system includes a heating element, a discharge air temperature sensor, and a return air temperature sensor. A controller of the HVAC system determines that the HVAC system has been operating in the heating mode for at least a predefined amount of time. The controller receives measurements of the discharge air temperature and the return air temperature. A temperature rise value is determined using the discharge air temperature and return air temperature. If the temperature rise value is less than a predefined minimum threshold value, the controller determines that a first fault of the HVAC system is detected and provides a corresponding alert. If the temperature rise value is greater than a predefined maximum threshold value, the controller determines that a second fault of the HVAC system is detected and provides a corresponding alert.

Abstract: A defrost method for a heat pump system includes running the heat pump system in a heating mode to provide heat to an enclosed space and determining if an outdoor temperature is less than an outdoor threshold temperature. Responsive to a determination that the outdoor temperature is below the outdoor threshold temperature, determining if a calibration state has been previously run. Responsive to a determination that the calibration state has not been previously run, running the heat pump system in the calibration state. Responsive to a determination that the calibration state has been previously run, determining if a temperature difference between a temperature of an evaporator coil of the heat pump system and the outdoor temperature exceeds a temperature threshold value. Responsive to a determination that the temperature difference between the evaporator coil and the outdoor temperature is greater than the temperature threshold value, running the heat pump system in a defrost state.

Abstract: A method of minimizing components of a heating, ventilation, and air conditioning (HVAC) system from malfunctioning, the method includes measuring, by an accelerometer associated with at least one component of the HVAC system, vibration of the at least one component and receiving, by a controller, actual vibration data reflective of the measured vibration. The method further includes determining, using the controller, whether the actual vibration data is greater than pre-defined acceptable baseline vibration data by more than a pre-defined acceptable amount and responsive to a positive determination in the determining step, adding, by the controller, as a deadband frequency, an operational frequency of the at least one component corresponding to the actual vibration data.

Abstract: The present invention is a liquid fertilizer comprising a calcium cyanamide component that is dissolved, co-applied, dispersed, or suspended in a solution of aqueous triazone urea. The combination of calcium cyanamide and triazone urea produces a slow release of nitrogen that requires fewer reapplications and is more effective than heretofore fertilizers. In one preferred embodiment, the fertilizer or plant treatment is further combined with a soil treatment including polycarboxylate acids and polyaliphatic acid salts in combination with potash to further enhance the properties of the fertilizer.

Abstract: Novel techniques are described for discharging high voltage components. For example, a tool is provided to discharge high-voltage capacitors in electrical appliances prior to servicing those appliances. The tool can include a handle structure electrically and physically isolated from a head structure by an elongated body. The elongated body can house at least a portion of a discharge circuit configured to discharge high-voltage components and to indicate (visually, audibly, etc.) whether voltage is present on components being discharged. The head structure can include multiple probes adapted to electrically couple the tool with the high-voltage components and through which to discharge the components.

Abstract: A method of minimizing components of a heating, ventilation, and air conditioning (HVAC) system from malfunctioning, the method includes measuring, by an accelerometer associated with at least one component of the HVAC system, vibration of the at least one component and receiving, by a controller, actual vibration data reflective of the measured vibration. The method further includes determining, using the controller, whether the actual vibration data is greater than pre-defined acceptable baseline vibration data by more than a pre-defined acceptable amount and responsive to a positive determination in the determining step, adding, by the controller, as a deadband frequency, an operational frequency of the at least one component corresponding to the actual vibration data.

Abstract: The current disclosure provides for methods of manufacturing a balance ring assembly. Such a method includes the steps of securing an upper ring component to a drive head; securing a lower ring component to the weld joint of a base platform; moving the drive head linearly from a home position to a pre-determined touch position; upon reaching the pre-determined touch position, applying a first pressure to the upper ring component and lower ring component; rotating the drive head to move the upper ring component along a first rotational path relative to the lower ring component; and moving the drive head linearly a first distance to move the upper ring component toward the lower ring component and moving the drive head rotationally to move the upper ring component along a second rotational path relative to the lower ring component.