Abstract: Examples of the present disclosure relate to climate control systems and outdoor units that use humidity measurements associated with the outdoor environment to improve the operation of one or more components. In some examples, an outdoor unit of a climate control system includes a housing, a compressor located within the housing that circulate a refrigerant fluid, and a humidity sensor that detects a humidity condition of an outdoor environment. The outdoor unit may further include control circuitry that controls the compressor by establishing a target parameter, where the target parameter is associated with a property of a refrigerant fluid. The control circuitry may further receive measurements associated with the humidity condition of the outdoor environment, adjust the target parameter based on the measurement, monitor the property of the refrigerant fluid, compare the monitored property to the adjusted target parameter, and adjust operation of the compressor based on the comparison.

Abstract: Example embodiments of the present disclosure relate to a sealing apparatus including a gasket for use in connecting HVAC fluid conduits. In one embodiment, the gasket includes a tubular body, a rim extending outwardly from an end of the tubular body, and two or more ears extending from the rim. The tubular body may be configured to engage a fluid conduit. Each of the ears may be spaced apart from the tubular body and extend in substantially the same direction as the tubular body. Each of the ears may further include an inner surface for engaging with a fluid conduit and an outer surface for engaging with a pipe clamp. The ears may further include a rib located proximate a distal end of the ear.

Abstract: A switchable filtration system for a heating, ventilation, air conditioning, and refrigeration (HVACR) system is disclosed. The filtration system includes a first filter, a second filter, a switching apparatus, and a controller. The controller is configured to determine an air quality score. When the air quality score exceeds a predetermined threshold, the controller controls the switching apparatus to switch the first filter out of an active airflow path. When the air quality score is at or below the predetermined threshold, the controller controls the switching apparatus to switch the first filter into the active airflow path.

Abstract: A porous gas bearing is disclosed. The porous gas bearing includes a housing having a fluid inlet and an aperture. A porous surface layer is disposed within the housing surrounding the aperture in a circumferential direction. The porous surface layer is in fluid communication with the fluid inlet. A damping system includes a damping system including a biasing member, the biasing member being disposed in a passageway that extends along the longitudinal direction of the aperture and circumferentially about the aperture, wherein the biasing member is arranged radially outward from the porous surface layer.

Abstract: Multiple air handling units feeding into a common air distribution system are used to provide both latent and sensible temperature control. When dehumidification without sensible cooling is required, different air handling units feeding into a common distribution system may be operated in different modes so that both cooling and reheating are occurring simultaneously. The result is an energy efficient means of controlling both ambient air temperature and relative humidity. Air handling units such as water source heat pumps and variable refrigerant flow (VRF) units may be employed.

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 throttle ring disposed between stages of the compressor. The throttle ring can allow or obstruct flow through the side stream injection port. The throttle ring can extend and retract in a direction substantially perpendicular to the direction of flow from the first stage impeller to the second stage impeller. A method of operating a centrifugal compressor can include actuating a throttle ring by rotating a drive ring to adjust a flow of interstage fluid into the second stage impeller.

Abstract: Architectures or techniques are presented that can determine a setting for an environment control (EC) or HVAC system in response to a fault with the EC system that controls an environment of an occupant. Significantly, the determined setting can be intentionally selected as one that does not comport with the expectations or desired comfort level of the occupant. Thus, a condition can be created in the environment that is determined to be likely to cause the occupant to examine a user interface associated with the EC system. The user interface can present an indication of the fault, which otherwise may go unnoticed, particularly in cases where the occupant has no reason to interact with the EC system due to the environment meeting expectations.

Abstract: A heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a compressor with a gas bearing supplied with compressed gas and a controller. The controller is configured to determine an inlet pressure and outlet pressure of the gas bearing, determine a maximum speed limit based on the inlet pressure and the outlet pressure, and prevent the compressor from operating at a speed that is greater than the maximum speed limit. A method of controlling a compressor includes calculating a maximum speed limit based on an inlet pressure and an outlet pressure of the gas bearing. The method also includes in response to determining that a speed setting is greater than the maximum speed limit, adjusting operation of the compressor such that a speed of the compressor is at or below the maximum speed limit.

Abstract: Systems and methods are used to control operation of a rotary compressor of a refrigeration system to improve efficiency by varying the volume ratio and the speed of the compressor in response to current operating and load conditions. The volume of the axial and/or radial discharge ports of the compressor can be varied to provide a volume ratio corresponding to operating conditions. In addition, permanent magnet motors and/or control of rotor tip speed can be employed for further efficiency gains.

Abstract: Aligning a motor shaft in a fan assembly is described. Aligning a centerline of a motor shaft in a direct drive fan assembly includes selecting a motor from among a plurality of motors and matching a motor-plate from among a plurality of motor plates to the motor, the matched motor plate is based on the selected motor. Aligning the centerline further includes creating, from the selected motor and the matching motor plate, a motor-plate assembly that has a resulting height, where the resulting height of the motor-plate assembly corresponds to a particular height of a direct drive fan assembly, and aligning the centerline of a motor shaft of the motor-plate assembly to the direct drive fan assembly, where the particular height of the direct drive fan assembly is constant.

Abstract: An interstage throttle for a centrifugal compressor includes a flow guide plate, a throttle ring, a drive ring, and linkage assemblies. The flow guide plate includes guide vanes that form channels that direct working fluid in between stages of the compressor. The linkage assemblies connect the drive ring to the throttle ring such that rotation of the drive ring moves the throttle ring in an axial direction. Teeth of the throttle ring partially block the channels when the throttle ring is in an extended position. A method of operating a centrifugal compressor includes directing the working fluid discharged from the first stage to a second stage via channels in a interstage throttle. A centrifugal compressor includes a first stage with a first impeller, a second stage with a second impeller, and an interstage throttle fluidly connecting the first stage to the second stage.

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: Methods and systems for performing an electronic security assessment of a building automation system are provided. The building automation system includes a controller and a network of electronic devices connected in electronic communication. The method includes requesting, by the controller, an electronic security scan of the controller with a data set of the controller via a secured channel to a cloud-based service. The method also includes initiating the electronic security scan of the controller based on the data set of the controller. The method further includes electronically assessing security vulnerabilities of the building automation system. The method also includes electronically assessing, by the controller, security vulnerabilities of the network of electronic devices connected in electronic communication with the controller.

Abstract: A method is provided for controlling heating, ventilation and air conditioning (HVAC) equipment configured to control environmental conditions in confined areas of a facility. The method includes monitoring at least one of the HVAC equipment or the confined areas. The method includes detecting a failure of a first of the HVAC equipment to control an environmental condition in a first of the confined areas to a setpoint for the environmental condition, with the environmental condition including at least one of temperature, humidity or air quality. The method includes controlling at least one of the first or a second of the HVAC equipment to cause additional conditioned air to permeate to the first of the confined areas from an adjacent, second of the confined areas to move the environmental condition in the first of the confined areas closer to the setpoint to compensate for the failure, automatically as a direct result of detection of the failure.

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: A computer-implemented method and building automation system, the building automation system including a network of electronic devices connected in electronic communication. The method includes initiating an electronic security scan of the controller. The controller electronically assesses security vulnerabilities of the controller, including identifying one or more of a validation of whether the controller is protected by a firewall or other network security device, identifying which communication ports are open, identifying and verifying an Ethernet and Wi-Fi configuration of the controller, determining whether any routers communicating with the controller are protected by the firewall or other network security device, determining whether the controller is running an up-to-date software or firmware version, and determining a listing of software applications and versions installed on the controller.

Abstract: HVAC components having improved efficiency are described. In one embodiment, excessive sleep current draw in a battery-powered device having a microcontroller is detected by measuring a voltage drop across a MOSFET device coupled in a forward-conducting orientation in series between the battery and the microcontroller, causing a transistor to conduct when the voltage drop exceeds a predetermined threshold to generate a first trigger signal, integrating the first trigger signal to generate a second trigger signal, and generating an interrupt to the microcontroller. In another embodiment, a battery-saving method of operating an HVAC component includes maintaining the HVAC device in the sleep mode, receiving a user input to wake the device, transmitting a data request and returning the HVAC component to the sleep mode, waking up the HVAC device to poll an adjacent network node storing a cached response, displaying the response, and returning the HVAC device to sleep.

Abstract: An air handler includes a housing with a heat exchanger core. The housing includes a faceplate, a roof panel, a base panel, a first side panel, and a second side panel. A first tunnel and a second tunnel are connected to the housing at the faceplate. A septum protrudes from the faceplate and connects the core at a front edge. The air handler further includes a first recirculation path and a second recirculation path inside the housing. The first and second recirculation paths are defined by the septum, the housing, and the core. The first and second recirculation paths are configured to direct a portion of airflow from the first tunnel to the second tunnel. The air handler further includes a first damper and a second damper disposed on the faceplate and configured to obstruct the first recirculation path and the second recirculation path respectively.

Abstract: Embodiments of vibration damping clips for use within a climate control system are disclosed. In an embodiment, a vibration damping clip is engaged with three fluid lines of an outdoor unit of the climate control system, such as, for instance, a suction line of a compressor of the climate control system, a discharge line of the compressor, and a fluid line coupled to a pressure equalization valve (PEV) within the outdoor unit.

Abstract: Example furnaces and methods related thereto include a burner box including at least one burner configured to combust a fuel/air mixture. In addition, the furnace includes a first blower including an inlet nozzle having an air inlet and fuel inlet. The inlet nozzle is configured such that operation of the first blower is to pull air and fuel into the inlet nozzle to produce the fuel/air mixture at a fuel/air ratio that is configured to produce flue products having less than 14 Nano-grams per Joule of nitrogen oxides when combusted. Operation of the first blower is configured to push the fuel/air mixture into the burner box. Further, the furnace includes a heat exchanger assembly fluidly coupled to the burner box through a vestibule, and a second blower configured to pull the flue products through the heat exchanger assembly.