Abstract: Refrigerant leak detection systems as well as related climate control systems and methods are disclosed herein. In an embodiment, the refrigerant leak detection system includes a transmitter configured to emit an acoustic wave, and a receiver configured to detect the acoustic wave. The transmitter and the receiver are mounted within a space outside a conduit configured to carry a refrigerant of a climate control system. In addition, the refrigerant leak detection system includes a controller coupled to the transmitter and the receiver. The controller is configured to: determine a time of flight for the acoustic wave between the transmitter and the receiver, and determine whether a refrigerant is present in the space based on the time of flight.

Abstract: Example embodiments of the present disclosure relate to a climate control system and methods for controlling the system. Some embodiments include a system that includes a refrigerant circuit with both a main circuit and a bypass circuit, where the main circuit directs the refrigerant fluid from a compressor to a first heat exchanger, a metering device, a second heat exchanger, and an accumulator, and the bypass circuit selectively directs a portion of the refrigerant fluid to a third heat exchanger. The bypass circuit may include a bypass control valve and a bypass metering device, the bypass control valve controlling the flow of the portion of the refrigerant fluid to be directed to the third heat exchanger, and the bypass metering device lowering the temperature of the portion of the refrigerant fluid before the portion of the refrigerant fluid enters the third heat exchange. The third heat exchanger may be located proximate the accumulator.

Abstract: Methods and related systems for charging a refrigerant into a climate control system. In an embodiment, the method includes (a) coupling a storage tank to a refrigerant loop of the climate control system through a charging valve; (b) opening and closing the charging valve in a plurality of cycles; and (c) flowing refrigerant from the storage tank to the refrigerant loop through the charging valve when the charging valve is open, during (b). In addition, the method includes (d) determining a detected saturated temperature of the refrigerant within the refrigerant loop after each cycle of the plurality of cycles; and (e) adjusting an amount of time that the charging valve is open during each cycle of the plurality of cycles during (b) as a function of the detected saturated temperature from a previous cycle of the plurality of cycles.

Abstract: Methods and related systems for operating a climate control system for an indoor space are disclosed. In an embodiment, the method includes increasing a speed of a fan of the climate control system, and determining a first fitted external static pressure (ESP) function from a first plurality of airflow values and a first plurality of ESP values. Additionally, the method includes obtaining a baseline ESP from the first fitted ESP function, and determining a second fitted ESP function from a second plurality of airflow values and a second plurality of ESP values collected at least one week after the first plurality of airflow values and the first plurality of ESP values are collected. Further, the method includes comparing the first calculated ESP obtained from the second fitted ESP function to the baseline ESP to determine a condition of an air filter of the climate control system.

Abstract: Methods and related systems for charging a refrigerant into a climate control system. In an embodiment, the method includes (a) coupling a storage tank to a refrigerant loop of the climate control system through a charging valve; (b) opening and closing the charging valve in a plurality of cycles; and (c) flowing refrigerant from the storage tank to the refrigerant loop through the charging valve when the charging valve is open, during (b). In addition, the method includes (d) determining a detected saturated temperature of the refrigerant within the refrigerant loop after each cycle of the plurality of cycles; and (e) adjusting an amount of time that the charging valve is open during each cycle of the plurality of cycles during (b) as a function of the detected saturated temperature from a previous cycle of the plurality of cycles.

Abstract: Refrigerant leak detection systems as well as related climate control systems and methods are disclosed herein. In an embodiment, the refrigerant leak detection system includes a transmitter configured to emit an acoustic wave, and a receiver configured to detect the acoustic wave. The transmitter and the receiver are mounted within a space outside a conduit configured to carry a refrigerant of a climate control system. In addition, the refrigerant leak detection system includes a controller coupled to the transmitter and the receiver. The controller is configured to: determine a time of flight for the acoustic wave between the transmitter and the receiver, and determine whether a refrigerant is present in the space based on the time of flight.

Abstract: Refrigerant leak detection systems as well as related climate control systems and methods are disclosed herein. In an embodiment, the refrigerant leak detection system includes a transmitter configured to emit an acoustic wave, and a receiver configured to detect the acoustic wave. The transmitter and the receiver are mounted within a space outside a conduit configured to carry a refrigerant of a climate control system. In addition, the refrigerant leak detection system includes a controller coupled to the transmitter and the receiver. The controller is configured to: determine a time of flight for the acoustic wave between the transmitter and the receiver, and determine whether a refrigerant is present in the space based on the time of flight.

Abstract: Embodiments relate generally to subcooling control of a heating, ventilation, and air conditioning (HVAC) system. An HVAC system may include a first electronic expansion valve (EEV) fluidly coupled to an indoor coil, wherein the first EEV is adjacent to the indoor coil. The HVAC system may also include a second EEV fluidly coupled to an outdoor coil, wherein the second EEV is adjacent to the outdoor coil. A system controller may be configured to control the first and second EEVs to control a flow of refrigerant to control subcooling (SC) produced by the HVAC system. The second EEV remains open during a cooling mode, and the first EEV modulates during the cooling mode. The second EEV modulates during a heating mode, and the first EEV remains open during the heating mode.

Abstract: Methods and related systems for charging a refrigerant into a climate control system. In an embodiment, the method includes (a) coupling a storage tank to a refrigerant loop of the climate control system through a charging valve; (b) opening and closing the charging valve in a plurality of cycles; and (c) flowing refrigerant from the storage tank to the refrigerant loop through the charging valve when the charging valve is open, during (b). In addition, the method includes (d) determining a detected saturated temperature of the refrigerant within the refrigerant loop after each cycle of the plurality of cycles; and (e) adjusting an amount of time that the charging valve is open during each cycle of the plurality of cycles during (b) as a function of the detected saturated temperature from a previous cycle of the plurality of cycles.

Abstract: Methods and related systems for measuring a temperature with an onboard sensor of a device of a heating, ventilation, and air conditioning (HVAC) system are disclosed. In an embodiment, the method includes (a) changing a power state of the device from off to on, and (b) detecting a raw temperature with the sensor after (a). In addition, the method includes (c) determining a time offset along a predetermined time and temperature relationship for the device, and (d) calculating a temperature offset with the predetermined time and temperature relationship at the time offset. Further, the method includes (e) subtracting the temperature offset from the raw temperature.

Abstract: Refrigerant leak detection systems as well as related climate control systems and methods are disclosed herein. In an embodiment, the refrigerant leak detection system includes a transmitter configured to emit an acoustic wave, and a receiver configured to detect the acoustic wave. The transmitter and the receiver are mounted within a space outside a conduit configured to carry a refrigerant of a climate control system. In addition, the refrigerant leak detection system includes a controller coupled to the transmitter and the receiver. The controller is configured to: determine a time of flight for the acoustic wave between the transmitter and the receiver, and determine whether a refrigerant is present in the space based on the time of flight.

Abstract: Embodiments relate generally to subcooling control of a heating, ventilation, and air conditioning (HVAC) system. An HVAC system may include a first electronic expansion valve (EEV) fluidly coupled to an indoor coil, wherein the first EEV is adjacent to the indoor coil. The HVAC system may also include a second EEV fluidly coupled to an outdoor coil, wherein the second EEV is adjacent to the outdoor coil. A system controller may be configured to control the first and second EEVs to control a flow of refrigerant to control subcooling (SC) produced by the HVAC system. The second EEV remains open during a cooling mode, and the first EEV modulates during the cooling mode. The second EEV modulates during a heating mode, and the first EEV remains open during the heating mode.

Abstract: A two temperature electronic expansion valve control for variable speed compressors that utilizes a correlation between airflow percentage and heat exchanger pressure drop to control the operation of an expansion valve. An indoor airflow percentage request may be communicated from an outdoor controller to an air handler controller. Using a correlation between airflow percentage and pressure drop across the heat exchanger, the airflow percentage may be used in predicting an outlet pressure of refrigerant exhausted from the heat exchanger. The predicted pressure drop may be used in determining a saturated temperature for the exhausted refrigerant. The determined saturated temperature may be compared to a sensed temperature of the refrigerant at the outlet of the heat exchanger to determine a superheat value, which is compared to a reference superheat value in determining the degree to open or close the expansion valve.

Abstract: Systems and methods are disclosed herein that include controlling operation of a heating, ventilation, and/or air conditioning (HVAC) system that utilizes information from a plurality of temperature sensors to monitor, verify, determine, and/or discover whether a temperature sensor is properly located in proximity to a dome of a compressor of the HVAC system. When the HVAC system determines that the temperature sensor associated with the dome of the compressor is not properly located, the HVAC system may initiate a shutdown of the compressor and/or other components of the HVAC system, generate a signal, present a message, and/or otherwise provide a notification of the improper temperature sensor placement, and/or reduce a runtime of the compressor, operate the compressor at a lower speed, reduce a power consumption of the compressor, and/or otherwise control the compressor and/or associated components to effectuate a reduced compressor dome temperature.

Abstract: Systems and methods of controlling an HVAC system electronic expansion valve (EEV) include determining an optimal EEV position for the HVAC system as a function of a variable related to an ambient environment enthalpy and operating the HVAC system as a function of the optimal EEV position.

Abstract: Detection of reverse rotation or operation of a refrigerant compressor is provided. In one aspect, a detection technique includes starting the compressor and determining the compressor is rotating in a reverse direction if a dome temperature of the compressor fails to exceed a first predetermined threshold at or before expiration of a first predetermined period of time following starting, the refrigerant pressure at a refrigerant inlet of the compressor remains constant for a second predetermined period of time following starting, and/or the frequency of pressure oscillations of the refrigerant at the refrigerant inlet exceeds a second predetermined threshold. Another technique for determining the compressor is rotating in the reverse direction involves analyzing a waveform associated with motor current, motor torque, or refrigerant pressure. Further embodiments, forms, features, and aspects shall become apparent from the description and drawings.

Abstract: An apparatus and method for controlling the heating of an airflow. According to certain embodiments, the temperature of an outdoor heat exchanger and the speed of a compressor are used to determine a blower speed for a variable speed indoor air blower. The selected blower speed may facilitate a flow of air across a second, indoor heat exchanger at an indoor volumetric flow rate that heats the airflow to a leaving air temperature. The leaving air temperature may at least seek to attain the temperature of a variable target leaving air temperature that is adjusted based on changes in outdoor ambient temperatures. Additionally, according to certain embodiments, the blower speed may be based on an indoor volumetric airflow rate that is determined, at least in part, on a determined system heating capacity and a temperature at the outdoor heat exchanger.

Abstract: A comfort controller in an HVAC system is provided. The comfort controller comprises a processor configured such that the comfort controller compares at least one of an actual run time of the HVAC system to a benchmark run time and an actual static pressure of the HVAC system to a benchmark static pressure. The processor is further configured such that, when at least one of the actual run time and the actual static pressure are outside a specified range of their associated benchmarks, the comfort controller determines that the HVAC system has an improper configuration. The processor is further configured such that the comfort controller displays the results of the comparison.

Abstract: One embodiment is a diagnostic method for a system including setting a first diagnostic code based upon a condition of a DC bus of a variable frequency drive during a first drive state, setting at least one additional diagnostic code based upon a condition of at least one motor phase current during a second drive state, outputting first diagnostic information indicating a malfunction of the variable frequency drive if the first diagnostic code indicates a first error, and outputting second diagnostic information indicating a malfunction of a motor or a connector coupling the motor and the drive if the at least one additional diagnostic code indicates a second error.

Abstract: Systems and methods of controlling an HVAC system electronic expansion valve (EEV) include determining an optimal EEV position for the HVAC system as a function of a variable related to an ambient environment enthalpy and operating the HVAC system as a function of the optimal EEV position.