Abstract: An indoor air quality (IAQ) system for a building includes an IAQ sensor that is located within the building and that is configured to measure an IAQ parameter. The IAQ parameter is one of: an amount of particulate of at least a predetermined size present in air; an amount of volatile organic compounds (VOCs) present in air; and an amount of carbon dioxide present in air. A mitigation module is configured to: selectively turn on a mitigation device based on a comparison of the IAQ parameter with a first ON threshold and a second ON threshold; and selectively turn off the mitigation device based on a comparison of the IAQ parameter with an OFF threshold. A clean module is configured to determine a clean value for the IAQ parameter. A thresholds module is configured to, based on the clean value, determine the first ON threshold and the OFF threshold.

Abstract: A method of manufacturing an impeller includes attaching blades to a hub. The impeller includes the blades, the hub, and a shroud. The blades each include a tip, and the shroud includes an inner surface and at least one ring extending from the inner surface. The method also includes applying a brazing compound to the tips of the blades and to the inner surface of the shroud. The method includes inserting the blades and the hub into the shroud such that the tips of the blades press against the rings. The rings and the tips of the blades form an interference fit between the rings and the tips of the blades that maintains a consistent gap between the shroud and the blades during manufacture of the impeller. A compressor including the impeller is also disclosed.

Abstract: Disclosed are a main bearing seat for a scroll compressor, and a scroll compressor. The main bearing seat comprises substantially ring-shaped thrust parts for supporting a compressing mechanism of the scroll compressor, and a main part body provided with a bearing to support a driving shaft of the scroll compressor, wherein multiple suspension parts extending in a radial direction of the scroll compressor are provided in the thrust parts, and the suspension parts are arranged in an axial direction of the scroll compressor.

Abstract: Systems and methods for purging lubricant from a first compressor to a second compressor are provided. A control module receives a lubricant purge command, shuts the second compressor to an OFF-mode while the first compressor remains in the ON-mode, restricts working fluid from an outlet of the second compressor from flowing into the first compressor and allows compressed working fluid discharged from an outlet of the first compressor to flow into the inlet of the second compressor such that lubricant in the second compressor flows into the first compressor.

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 heat-pump system may include an outdoor heat exchanger, an expansion device, an indoor heat exchanger, a compressor, and a multiway valve. The expansion device is in fluid communication with the outdoor heat exchanger. The indoor heat exchanger is in fluid communication with the expansion device. The compressor circulates working fluid through the indoor and outdoor heat exchangers. The multiway valve may be movable between a first position corresponding to a cooling mode of the heat-pump system and a second position corresponding to a heating mode of the heat-pump system. The working fluid flows in the same direction through the outdoor heat exchanger in the cooling mode and in the heating mode, and the working fluid flows in the same direction through the indoor heat exchanger in the cooling mode and in the heating mode.

Abstract: A compressor may include first and second scrolls, a hub plate and a valve member. The first scroll includes an end plate having a primary discharge passage and a secondary discharge passage. The secondary discharge passage is disposed radially outward from the primary discharge passage. The hub plate is mounted to the first scroll and has a hub discharge passage extending therethrough. The hub discharge passage is in fluid communication with the primary discharge passage. The valve member is movable between open and closed positions. The valve member restricts fluid flow through the secondary discharge passage when in the closed position to restrict fluid communication between the secondary discharge passage and the hub discharge passage. The valve member allows fluid flow through from the secondary discharge passage when in the open position to allow fluid communication between the secondary discharge passage and the hub discharge passage.

Abstract: A system includes a dynamic compressor, a variable frequency drive (VFD), and a controller. The dynamic compressor includes a motor having a driveshaft rotatably supported within the dynamic compressor, and a compression mechanism connected to the driveshaft and operable to compress a working fluid upon rotation of the driveshaft. The VFD includes a sensor configured to sense a current provided to the motor. The controller is connected to the motor and includes a processor and a memory. The memory stores instructions that program the processor to operate the motor using the VFD to compress the working fluid, receive signals representing the current from the VFD to the motor, and determine when a surge event has occurred based at least in part on the received signals representing the current from the VFD to the motor.

Abstract: A climate-control system may include first and second compressors, first and second suction valves, and a control module. The first and second compressors each include a shell and a compression mechanism. The shells define suction chambers from which the compression mechanisms draw working fluid. The shells include suction inlets through which working fluid is drawn into the suction chambers. The first suction valve may be movable between a fully open position and a partially closed position and may control a flow of working fluid through the first suction inlet. The second suction valve may be movable between a fully open position and a partially closed position and may control a flow of working fluid through the second suction inlet. The control module may control positions of the first and second suction valves to control lubricant levels in the first and second shells.

Abstract: First and second IAQ sensors are located within a building and are configured to measure first and second IAQ parameters, respectively, the first and second IAQ parameter being the same one of: relative humidity; amount of particulate; amount of volatile organic compounds; and amount of carbon dioxide. A mitigation device is separate from an HVAC system and includes a control module configured to turn the mitigation device on and off based on the first IAQ parameter, the second IAQ parameter, and whether the HVAC system is on or off. A mitigation module is configured to selectively turn the HVAC system on and off based on the second IAQ parameter, the first IAQ parameter, and whether the HVAC system is on or off.

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: Disclosed is a scroll compressor including: an orbiting scroll having an orbiting scroll end plate and an orbiting volute formed on one side of the orbiting scroll end plate, and a fixed scroll having a fixed scroll end plate and a fixed volute formed on one side of the fixed scroll end plate. The fixed and orbiting scrolls match each other in order to form a series of compression cavities therebetween including a central compression cavity and middle compression cavities located radially outside of the central compression cavity, and. The middle compression cavities include at least a set of a first middle compression cavity and a second middle compression cavity. A fluid channel selectively communicating with a discharge area is provided between the first and second middle compression cavities, and the first middle compression cavity directly communicates with the second middle compression cavity by means of the fluid channel.

Abstract: A scroll compressor includes a fixed scroll, a movable scroll, a main bearing housing and an axial compliance mounting mechanism. The fixed scroll is engaged with the movable scroll to compress a working fluid. The main bearing housing has a bearing surface for supporting a movable scroll end plate. The fixed scroll is fixedly connected to a connecting portion of the main bearing housing by the axial compliance mounting mechanism so that the fixed scroll can move in the axial direction by a predetermined distance. The fixed scroll further includes a flange extending radially outward from a circumferential wall portion, having an axial geometric center position between a first surface and a second surface and positioned such that the axial geometric center position is closer to the movable scroll end plate than the axial middle position thereof. The structure can prevent or reduce damage to the axial compliance mounting mechanism.

Abstract: Provided is a scroll compressor, comprising a compression mechanism and a valve assembly. The compression mechanism is provided with a vent, and the valve assembly is used for selectively opening and closing the vent. The valve assembly comprises a valve plate and at least one valve piece. The valve plate comprises at least one valve orifice; and the valve piece is configured to selectively open and close the valve orifice. The scroll compressor further comprises a guide passageway. The guide passageway is provided with a first port communicating with the valve orifice and a second port communicating with the exhaust opening. The valve assembly and the compressor can significantly prolong the service life of the valve piece, and can provide good guidance for a fluid discharged from the compression mechanism, thereby significantly reducing the resistance of venting and the fluid pressure drop, and improving the effect of venting.

Abstract: A compressor includes a shell assembly, a compression mechanism and a conduit. The shell assembly defines a chamber. The compression mechanism is disposed within the chamber of the shell assembly and includes a first scroll member and a second scroll member in meshing engagement with each other. The second scroll member includes a suction inlet. The conduit directs working fluid into the suction inlet and includes a first end defining an inlet opening and a second end defining an outlet opening adjacent to the suction inlet. The second end includes a locating pin that extends outwardly therefrom.

Abstract: A compressor includes a shell, a muffler plate, first and second scroll members, and first and second sealing members. The shell defines first and second pressure regions separated by the muffler plate. The first scroll member includes a first end plate and a first scroll wrap. The first end plate defines an annular recess and a discharge recess. The discharge recess is in communication with the first pressure region. The second scroll member includes a second end plate and a second scroll wrap. The second scroll wrap meshingly engages the first scroll wrap to define a compression chamber therebetween. The first sealing member is at least partially disposed in the discharge passage and fluidly separates the first and second pressure regions from each other. The second sealing member is at least partially disposed in the annular recess.

Abstract: A foil bearing assembly includes a cylindrical body that defines a cooling fluid passage between a radial outer surface and a radial inner surface of the cylindrical body. The foil bearing assembly includes a foil bearing retained within the cylindrical body and in thermal communication with the radial inner surface of the cylindrical body. The foil bearing assembly is connectable to a bearing housing such that intake and outlet ports of the foil bearing assembly are connected in fluid communication with a coolant inlet passage and a coolant outlet passage defined by the bearing housing. The foil bearing assembly is interchangeable with a second foil bearing assembly having at least one of a cooling fluid passage, a foil bearing, and a cylindrical body inner diameter different than the corresponding cooling fluid passage, the foil bearing, and the cylindrical body inner diameter of the first foil bearing assembly.

Abstract: A scroll expander, comprising: a housing; and an expansion mechanism provided in the housing. A back pressure chamber in fluid communication with a medium pressure chamber is provided in the expansion mechanism and is provided with at least one passage in fluid communication from the back pressure chamber to a low pressure region; the passage is configured such that: the passage is opened when the pressure in the back pressure chamber is lower than the pressure of the low pressure region, and is closed when the pressure in the back pressure chamber is higher than or equal to the pressure of the low pressure region. The scroll expander can avoid the problem of being unable to be started and to operate normally; and the scroll expander is simple in structure, easy to process and manufacture, and high in cost effectiveness.

Abstract: A drive circuit is provided and includes a rectification circuit, a buck converter, a first inverter, and a second inverter. The rectification circuit is configured to rectify a first AC voltage signal to generate a rectified voltage signal. The buck converter is configured to downconvert the rectified voltage signal to a DC voltage signal, wherein the DC voltage signal is supplied to a DC bus. The first inverter is configured to convert the DC voltage signal to a second AC voltage signal and supply the second AC voltage signal to a compressor motor. The second inverter is configured to convert the DC voltage signal to a third AC voltage signal and supply the third AC voltage signal to a condenser fan motor. Peak voltages of the second AC voltage signal and the third AC voltage signal are less than peak voltages of the first AC voltage signal.

Abstract: A heating, ventilation, and air conditioning system includes first and second fluids, a heat exchanger, a refrigerant sub-system, and at least one closed loop sub-system. The heat exchanger includes a membrane for channeling the first fluid through the heat exchanger and is disposed for heat transfer between the first fluid and the second fluid. The membrane defines an inlet having an inlet height relative to grade. The closed loop sub-system transfers heat from the heat exchanger to the refrigerant sub-system and includes an expansion tank containing the first fluid. A level of the first fluid within the expansion tank has a level height relative to grade. The expansion tank is positioned relative to the heat exchanger such that the inlet height is greater than the level height and the membrane is maintained in a collapsed configuration.