Abstract: A heat-pump system may include a compressor, an outdoor heating exchanger, an indoor heat exchanger, an expansion device, and a supplemental heater. The outdoor heat exchanger may be in fluid communication with the compressor. The indoor heat exchanger may be in fluid communication with the compressor. The expansion device may be in fluid communication with the indoor and outdoor heat exchangers. The supplemental heater may include a burner and a working-fluid conduit. The burner may be configured to burn a fuel and heat the working-fluid conduit. When the heat-pump system is operating in a heating mode, the indoor heat exchanger may receive working fluid from the working-fluid conduit such that the working fluid flows from an outlet of the working-fluid conduit to an inlet of the indoor heat exchanger.

Abstract: A refrigerant leak sensor includes: a first refrigerant sensor element configured to, when powered: measure a first amount of the refrigerant present in air; and generate a first output based on the first amount; a second refrigerant sensor element configured to, when powered: measure a second amount of the refrigerant present in air; and generate a second output based on the second amount; a first selection module configured to: during a first period, apply power the first refrigerant sensor element and not apply power to the second refrigerant sensor element; and during a second period after the first period, apply power to the second refrigerant sensor element and not apply power to the first refrigerant sensor element.

Abstract: A heat-pump system includes a compressor, an outdoor heating exchanger, an indoor heat exchanger, an expansion device, and a supplemental heater. The outdoor heat exchanger is in fluid communication with the compressor. The indoor heat exchanger is in fluid communication with the compressor. The expansion device is in fluid communication with the indoor and outdoor heat exchangers. The supplemental heater includes a burner and a working-fluid conduit. The burner is configured to burn a fuel and heat the working-fluid conduit. When the heat-pump system is operating in a heating mode, the indoor heat exchanger receives working fluid from the working-fluid conduit such that the working fluid flows from an outlet of the working-fluid conduit to an inlet of the indoor heat exchanger.

Abstract: A refrigerant control system includes: a charge module configured to determine an amount of refrigerant that is present within a first portion of a refrigeration system within a building; and an isolation module configured to selectively open and close an isolation valve of the refrigeration system and to, via the isolation valve, maintain the amount of refrigerant within the first portion within the building below a predetermined amount of the refrigerant.

Abstract: A refrigerant control system includes: a charge module configured to determine an amount of refrigerant that is present within a refrigeration system of a building; a leak module configured to diagnose that a leak is present in the refrigeration system based on the amount of refrigerant; and at least one module configured to take at least one remedial action in response to the diagnosis that the leak is present in the refrigeration system.

Abstract: A system for charging an outdoor unit with refrigerant includes a sensor configured to measure a refrigerant concentration and a user device configured to receive the measured refrigerant concentration. The system includes that the user device is configured to, in response to the measured refrigerant concentration exceeding a threshold, generate and display an alert on a user interface of the user device indicating the measured refrigerant concentration exceeds the threshold.

Abstract: A sensor control system includes: a refrigerant leak sensor configured to, when powered, measure an amount of a refrigerant present in air outside of a heat exchanger of a refrigeration system, where the heat exchanger is located within a building that is at least one of heated and cooled by the refrigeration system; and a power control module configured to one of: continuously power the refrigerant leak sensor; and disconnect the refrigerant leak sensor from power when a blower that moves air past the heat exchanger is on.

Abstract: A refrigerant measurement adjustment system includes: a refrigerant sensor for a building and configured to measure an amount of refrigerant present in air outside of a refrigeration system of the building; and an adjustment module configured to: adjust the amount of refrigerant measured based on an adjustment to produce an adjusted amount; and determine the adjustment based on at least one of: an air temperature; an air pressure; a relative humidity of air; a mode of operation of the refrigeration system; a change in the measurements of the refrigerant sensor over time; and whether a blower that blows air across a heat exchanger of the refrigeration system located within the building is on.

Abstract: A system for charging an outdoor unit with refrigerant includes a sensor configured to measure a refrigerant concentration and a user device configured to receive the measured refrigerant concentration. The system includes that the user device is configured to, in response to the measured refrigerant concentration exceeding a threshold, generate and display an alert on a user interface of the user device indicating the measured refrigerant concentration exceeds the threshold.

Abstract: A refrigerant leak sensor includes: a first refrigerant sensor element configured to, when powered: measure a first amount of the refrigerant present in air; and generate a first output based on the first amount; a second refrigerant sensor element configured to, when powered: measure a second amount of the refrigerant present in air; and generate a second output based on the second amount; a first selection module configured to: during a first period, apply power the first refrigerant sensor element and not apply power to the second refrigerant sensor element; and during a second period after the first period, apply power to the second refrigerant sensor element and not apply power to the first refrigerant sensor element.

Abstract: A heat-pump system may include a compressor, an outdoor heating exchanger, an indoor heat exchanger, an expansion device, and a supplemental heater. The outdoor heat exchanger may be in fluid communication with the compressor. The indoor heat exchanger may be in fluid communication with the compressor. The expansion device may be in fluid communication with the indoor and outdoor heat exchangers. The supplemental heater may include a burner and a working-fluid conduit. The burner may be configured to burn a fuel and heat the working-fluid conduit. When the heat-pump system is operating in a heating mode, the indoor heat exchanger may receive working fluid from the working-fluid conduit such that the working fluid flows from an outlet of the working-fluid conduit to an inlet of the indoor heat exchanger.

Abstract: A mitigation verification system includes: a control module configured to selectively transition a mitigation device of a refrigeration system of a building from a first state to a second state; and a verification module configured to verify and generate an indicator of whether the mitigation device of the refrigeration system transitioned from the first state to the second state based on a change in a parameter of the refrigeration system over a period in response to the transition by the control module.

Abstract: A refrigerant measurement adjustment system includes: a refrigerant sensor for a building and configured to measure an amount of refrigerant present in air outside of a refrigeration system of the building; and an adjustment module configured to: adjust the amount of refrigerant measured based on an adjustment to produce an adjusted amount; and determine the adjustment based on at least one of: an air temperature; an air pressure; a relative humidity of air; a mode of operation of the refrigeration system; a change in the measurements of the refrigerant sensor over time; and whether a blower that blows air across a heat exchanger of the refrigeration system located within the building is on.

Abstract: A sensor control system includes: a refrigerant leak sensor configured to, when powered, measure an amount of a refrigerant present in air outside of a heat exchanger of a refrigeration system, where the heat exchanger is located within a building that is at least one of heated and cooled by the refrigeration system; and a power control module configured to one of: continuously power the refrigerant leak sensor; and disconnect the refrigerant leak sensor from power when a blower that moves air past the heat exchanger is on.

Abstract: A system for charging an outdoor unit with refrigerant includes a sensor configured to measure a refrigerant concentration and a user device configured to receive the measured refrigerant concentration. The system includes that the user device is configured to, in response to the measured refrigerant concentration exceeding a threshold, generate and display an alert on a user interface of the user device indicating the measured refrigerant concentration exceeds the threshold.

Abstract: A refrigerant control system includes: a charge module configured to determine an amount of refrigerant that is present within a refrigeration system of a building; a leak module configured to diagnose that a leak is present in the refrigeration system based on the amount of refrigerant; and at least one module configured to take at least one remedial action in response to the diagnosis that the leak is present in the refrigeration system.

Abstract: A refrigerant control system includes: a charge module configured to determine an amount of refrigerant that is present within a first portion of a refrigeration system within a building; and an isolation module configured to selectively open and close an isolation valve of the refrigeration system and to, via the isolation valve, maintain the amount of refrigerant within the first portion within the building below a predetermined amount of the refrigerant.

Abstract: A sleeve connecting a blade to the hub of a rotor of a rotary wing aircraft. The sleeve has a leading edge and a trailing edge, together with a protuberance arranged on the trailing edge. The dimensions of the protuberance are linked to the dimensions of the sleeve. The presence of the protuberance serves to improve the aerodynamic behavior of the sleeve and of the rotor during rotation of the rotor while the aircraft is moving forwards, both when the sleeve is advancing and when it is retreating. The presence of the protuberance also serves to reduce the vibration generated by a wake of the rotor on a tail boom or on a horizontal and/or vertical stabilizer of the aircraft.

Abstract: A refrigerant control system includes: a charge module configured to determine an amount of refrigerant that is present within a refrigeration system of a building; a leak module configured to diagnose that a leak is present in the refrigeration system based on the amount of refrigerant; and at least one module configured to take at least one remedial action in response to the diagnosis that the leak is present in the refrigeration system.

Abstract: A system for detecting and mitigating a refrigerant leak includes a temperature control device configured to transmit control signals to a component controller and a blower configured to circulate air. The system includes a leak mitigation controller electrically coupled to the temperature control device and the component controller. The leak mitigation controller directs incoming power to the temperature control device. The leak mitigation controller includes a sensor configured to measure a refrigerant concentration and a relay configured to selectively: (i) connect the temperature control device to the incoming power or (ii) connect the blower to the incoming power. The leak mitigation controller is configured to measure the refrigerant concentration with the sensor and, in response to the measured refrigerant concentration exceeding a threshold, actuate the relay to connect the blower to the incoming power.