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: 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: 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 compressor system includes a variable-speed compressor and a fixed-speed compressor. A control unit is operatively coupled to the variable-speed compressor and is operatively coupled to the fixed-speed compressor. A sensor is operatively coupled to the control unit and disposed in an enclosed space. The sensor measures at least one of a temperature and a relative humidity of the enclosed space and determines an HVAC load of the enclosed space. Responsive to a determination of the HVAC load, the control unit directs operation of the variable-speed compressor and the fixed-speed compressor.

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 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: In one embodiment, an HVAC system includes an indoor unit having an indoor blower, an outdoor unit having a compressor and a condenser, an isolation valve coupled to the outdoor unit, and a sensor to detect a refrigerant leak. The HVAC system further includes one or more controllers operable to generate an alarm in response to the sensor detecting the refrigerant leak, operate the indoor blower in response to generating the alarm, close the isolation valve in response to generating the alarm, and operate the compressor to pump down the refrigerant to the condenser in response to generating the alarm.

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: An HVAC system includes an indoor unit having a return air duct and a supply air duct in an enclosed space. The HVAC system includes an outdoor unit having a variable-speed condenser fan. A first temperature sensor is disposed in at least one of the return air duct, the supply air duct, or an enclosed space. A controller is operatively coupled to the first temperature sensor, and the variable-speed condenser fan. The controller is configured to determine whether at least one of over-cooling or over-heating of air in the enclosed space is occurring. Responsive to a determination that at least one of over-cooling or over-heating of air in the enclosed space is occurring, the controller adjusts a speed of the variable-speed condenser fan.

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 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: Systems and methods are presented for improving stabilization of a heating, ventilating, and air conditioning (HVAC) system. More specifically, the systems and methods include a heat-flow modulator for regulating an exchange of thermal energy between a flow of refrigerant and a sensory bulb. The exchange of thermal energy allows an expansion valve to respond to a refrigerant temperature using an actuator, which is coupled to the sensory bulb. The heat-flow modulator is formed of a body that includes a first contact surface and a second contact surface. The first contact surface is thermally-coupled to a suction line of the HVAC system, which conveys the flow of refrigerant. The second contact surface is thermally-coupled to the sensory bulb. In one instance the heat-flow modulator has variable volume depending on how installed. Other systems and methods are presented. Variable heat-flow modulators are also presented.

Abstract: Methods, systems, and devices for defining an action node series at a database system are described. In some examples, the workflow may include one or more nodes are associated with an action. When executed, the workflow may produce an outcome based on the occurrence of an event or parameter associated with the one or more nodes. In some examples, the workflow may include one or more branch nodes. A branch node may include logic such that, when the workflow is executed, the logic selects a particular workflow path that includes its own specific nodes. The path may be selected based on the occurrence of an event or a value of one or more parameters. Thus, when a workflow including one or more branch nodes is executed, the outcome of the workflow may be based on the occurrence of the event or the value of the parameter.

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: In one embodiment, an HVAC system includes an indoor unit having an indoor blower, an outdoor unit having a compressor and a condenser, an isolation valve coupled to the outdoor unit, and a sensor to detect a refrigerant leak. The HVAC system further includes one or more controllers operable to generate an alarm in response to the sensor detecting the refrigerant leak, operate the indoor blower in response to generating the alarm, close the isolation valve in response to generating the alarm, and operate the compressor to pump down the refrigerant to the condenser in response to generating the alarm.

Abstract: Methods, systems, and devices for defining an action node series at a database system are described. In some examples, the workflow may include one or more nodes are associated with an action. When executed, the workflow may produce an outcome based on the occurrence of an event or parameter associated with the one or more nodes. In some examples, the workflow may include one or more branch nodes. A branch node may include logic such that, when the workflow is executed, the logic selects a particular workflow path that includes its own specific nodes. The path may be selected based on the occurrence of an event or a value of one or more parameters. Thus, when a workflow including one or more branch nodes is executed, the outcome of the workflow may be based on the occurrence of the event or the value of the parameter.

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.