Abstract: Heat exchangers and methods for assembling a heat exchanger are described, such as for example a round tube heat exchanger, which may be a fin and tube heat exchanger, and which may be used for example in a heating, ventilation, and air conditioning system (HVAC) system and/or unit thereof. The heat exchanger includes aluminum tubes mechanically rolled into an aluminum tube support and the tubes are fluidically sealed with the tube support. The aluminum tube support including the aluminum tubes rolled therein is assembled to a fluid manifold configured to allow fluid flow through the heat exchanger and into and/or out of the heat exchanger.

Abstract: A dynamic receiver is included in parallel to an expander of a heating, ventilation, air conditioning, and refrigeration (HVACR) system. The dynamic receiver allows control of the refrigerant charge of the HVACR system to respond to different operating conditions. The dynamic receiver can be filled or emptied in response to the subcooling observed in the HVACR system compared to desired subcooling for various operating modes. The HVACR system can include a line directly conveying working fluid from compressor discharge to the dynamic receiver to allow emptying of the dynamic receiver to be assisted by injection of the compressor discharge.

Abstract: Chiller control systems and methods for chiller control use iterative modeling of cooling towers, heat exchangers, and pumps to determine the feasibility of integrated free cooling and the ability to take advantage of free cooling. The control systems and control methods can further include selecting the parameters for operating in the free cooling or integrated free cooling mode to improve efficiency and/or reduce energy consumption when operating in these modes. The models can have inputs and outputs that feed into one another, and converge at a solution over multiple iterations. The feasibility of integrated free cooling can be based on providing cooling to a cooling load process fluid at a heat exchanger. The availability of free cooling can be based on the cooling provided at the heat exchanger achieving a target temperature for the cooling load process fluid.

Abstract: Centrifugal compressors can incorporate a side stream flow of intermediate pressure vapor between stages of that compressor. The side stream flow can be controlled by a side stream injection port controlled by a capacity control valve that has a curved surface facing a flow of refrigerant from the first stage to the second stage. The capacity control valve can allow or obstruct flow through the side stream injection port. The capacity control valve can extend and retract in a direction substantially perpendicular to the direction of flow from the first stage impeller to the second stage impeller. The side stream injection port and the capacity control valve can be ring-shaped. The side stream injection port and the capacity control valve can allow at least some of the side stream to be introduced on a side of the capacity control valve opposite the curved surface.

Abstract: A scroll compressor includes a compressor housing, an orbiting scroll member, a non-orbiting scroll member, an economizer injection inlet, and a discharge outlet. The orbiting scroll member and the non-orbiting scroll member are disposed within the compressor housing. The orbiting scroll member and the non-orbiting scroll member are intermeshed thereby forming a compression chamber within the compressor housing. The non-orbiting scroll includes a plurality of compression inlet ports. An economizer injection inlet is formed through the compressor housing and in fluid communication with the compression chamber via the compression inlet ports. The economizer injection inlet is disposed between the non-orbiting scroll member and the compressor housing. The discharge outlet is in fluid communication with the compression chamber.

Abstract: Methods and related systems of detecting a fault in a heating, ventilation, and air conditioning (HVAC) system are disclosed. In an embodiment, the method includes determining an expected runtime of the HVAC system required to achieve a temperature setpoint in a comfort zone of the HVAC system following a triggering event, wherein the expected runtime is based on a design temperature of a geographic location at which the HVAC system is installed. Additionally, the method includes monitoring a current runtime of the HVAC system elapsed following the triggering event, and comparing the expected runtime with the current runtime of the HVAC system elapsed following the triggering event.

Abstract: A suction duct is disposed within a shell and tube heat exchanger. The suction duct is located relatively high and above the tube bundle so as to not entrain liquid or droplets that may be splashing and spraying upward. The suction duct is configured with an area schedule in fluid communication with a flow path inside the suction duct. The flow path is in fluid communication with an outlet of the shell. This is advantageous relative to traditional top of the shell outlets which generally have higher vertical footprints. The area schedule of the suction duct can facilitate and/or maintain relatively smooth vapor flow within the shell. The area schedule can achieve vapor flows that have some uniformity along the length of the shell, which can manage and/or avoid localized vapor flow and/or local currents, such as where high velocity may be present and where entrainment can result.

Abstract: A heat exchanger, such as for example, a condenser coil constructed as a fin and microchannel tube is fluidly connected with a volume constructed and configured to store refrigerant in certain operations, such as for example during a pump down operation. The volume is fluidly connected to a fluid port of the heat exchanger, where the fluid port is an inlet (in the cooling mode) to the heat exchanger, such as the high side condensing section of the heat exchanger. The volume receives refrigerant exiting the heat exchanger from the fluid port in a mode other than a cooling mode, e.g., a pump down operation.

Abstract: This disclosure relates generally to cabinets for commercial heating, ventilation, air conditioning and refrigeration (HVACR) systems. More particularly, this disclosure relates to HVACR cabinets including one or more plenum fans located in a fan box. The fan box may be located between an indoor coil and a heat exchanger compartment of an HVACR unit. The fan box may be configured to direct air into a heat exchanger compartment inlet. The fan box may be parallel with or angled with respect to the indoor coil.

Abstract: Methods and related systems are disclosed for determining a temperature of an indoor space with a plurality of onboard sensors of a device of a climate control system. In an embodiment, the method includes detecting raw temperatures with the plurality of sensors. In addition, the method includes determining a combined temperature offset for a first sensor of the plurality of sensors based on outputs of a plurality of models. The plurality of models are to determine a plurality of temperature offsets for the first sensor based on different airflow directions relative to the device. Further, the method includes adjusting the raw temperature detected by the first sensor with the combined temperature offset.

Abstract: A refrigeration system is disclosed. The refrigeration system includes a refrigeration circuit including a compressor, a condenser, an expansion valve, and an evaporator fluidly connected. A purge circuit is fluidly connected to the condenser. The purge circuit is configured to receive a purge stream from the condenser. The purge stream is a mixture including a refrigerant and non-condensables. The purge circuit includes a plurality of heat exchangers for condensing the purge stream such that the non-condensables and the refrigerant in the purge stream are separated.

Abstract: A screw compressor, method of operating, and refrigerant circuit are disclosed. The screw compressor includes a suction inlet that receives a working fluid to be compressed. A compression mechanism is fluidly connected to the suction inlet that compresses the working fluid. A discharge outlet is fluidly connected to the compression mechanism that outputs the working fluid following compression by the compression mechanism. A valve assembly is configured to vary a location at which the compression mechanism compresses the working fluid, the valve assembly being disposed to modify a suction location of the screw compressor.

Abstract: An air handling unit for a heating, ventilation, air conditioning, and refrigeration system wherein the exhaust air is drawn away from the return air flow by one or more fans located cantilevered on a wall of the air handling unit. The one or more fans may be located within an exhaust hood, through which the exhaust air exits the air handling unit. This air handling unit has a shorter length through elimination of an exhaust fan section. The exhaust air may be drawn through an exhaust damper before being driven into the exhaust hood by the one or more fans. A method can include drawing an exhaust airflow through an exhaust damper, using fans positioned cantilevered on a wall of the air handling unit and directing the exhaust airflow into an exhaust hood mounted on the side wall of the air handling unit.

Abstract: Systems and methods to isolate a vibration source (e.g., a compressor) externally are disclosed. The embodiments generally include preventing/reducing vibration and/or pulsation transmission from the vibration source by one or more functional/structural isolating members, and preventing/reducing sound radiated from the vibration source by one or more sound enclosures.

Abstract: A method for providing personalized comfort to occupants of an environmentally conditioned space includes sensing a pre-adjustment pressure within a variable air volume diffuser, remotely adjusting a position an individually-adjustable directional outlet of the variable air volume diffuser, sensing a post-adjustment pressure within the variable air volume diffuser, and modifying the airflow through the variable air volume diffuser such that the post-adjustment pressure is equal to the pre-adjustment pressure. The variable air volume diffuser includes individually-adjustable directional outlets and a controller configured to regulate air pressure within the variable air volume diffuser when an individually adjustable directional outlet is adjusted. A user device in operative communication with the variable air volume diffuser includes a user interface to remotely adjust an adjustable directional outlet of the variable air volume diffuser to provide personalized comfort for the user.

Abstract: Cooling systems and methods of controlling a cooling system which includes one or more pumps and one or more fans, wherein the pumps and the fans are controlled by a controller. The controller controls the cooling system by a determination of an operation of the cooling system for sequencing activations, deactivations, and/or controlling parameters of the pumps, the fans, and/or other component(s) of the cooling system based on a first sensitivity of a power input as a function of lift, and a second sensitivity of a power input as a function of lift.

Abstract: Embodiments relate generally to subcooling control of a heating, ventilation, and air conditioning (HVAC) system. An HVAC system may include a compressor, a first heat exchanger, a refrigerant vessel having an inlet fluidly coupled to a discharge conduit extending from the compressor, and the refrigerant vessel having an outlet fluidly coupled to a liquid conduit, the liquid conduit configured to pass liquid refrigerant between the first heat exchanger and a second heat exchanger. The HVAC system may further include an electronic expansion valve (EEV) fluidly coupled between the discharge conduit and the inlet of the refrigerant vessel, wherein the EEV is configured to modulate and divert a portion of vapor refrigerant flowing through the discharge conduit into the refrigerant vessel to control subcooling (SC) produced by the HVAC system.

Abstract: Methods and related systems for detecting inaccurate airflow delivery of an indoor unit of a climate control system are disclosed. In an embodiment, the method includes operating a fan of the climate control system by transmitting a requested airflow value from a controller of the climate control system to a controller of the fan. Additionally, the method includes collecting estimated airflow values of the indoor fan, and identifying a steady state condition of the climate control system. Further, the method includes determining airflow error values, and issuing at least one of a first alert to a user of the climate control system in response to at least one of the airflow error values being equal to or greater than an alert value, and a second alert to the user in response to each of the airflow error values being less than the alert value.

Abstract: Methods and related systems for estimating input power supplied to a fan motor of a climate control system are disclosed. In an embodiment, the method includes selecting an input power function of a fan motor class. Additionally, the method includes operating a fan of the climate control system to produce an airflow, wherein the fan includes the fan motor of the selected fan motor class. Further, the method includes measuring a speed and a torque of the fan motor, and estimating an input power of the fan motor by entering the speed and the torque of the fan motor into the selected input power function.

Abstract: Systems, apparatus and methods for operating a chiller plant while minimizing or eliminating the occurrence of centrifugal compressor surge. Taking into account chiller design specifications and current operating conditions, a compressor lift point at which surge is predicted to occur is established. Minima and maxima for various chiller setpoints that avoid or eliminate the occurrence of compressor surge are imposed on setpoints provided by a conventional optimizing chiller controller. The chiller system is operated in accordance with the resultant anti-surge setpoints. Coolant tower flow is modulated to enable the compressor to operate at near-surge conditions while preventing the onset of actual surge.