Abstract: Heat exchangers for thermal storage systems include a valve that can direct process fluid passing through the heat exchanger through supplemental heat exchanger tubing based on a temperature of the process fluid. The supplemental heat exchanger tubing can be located in areas where ice formation can occur during freezing of the storage fluid of the thermal storage system, but apart from the standard flow path for the heat exchanger. The valve can be a thermally-actuated valve. The thermally actuated valve can be set to divert flow of the process fluid to the supplemental tubing when the process fluid is at or above a melting temperature of the storage fluid. Methods can include selectively flowing process fluid through supplemental heat exchange tubing when it is at a temperature greater than the melting point of a storage material.

Abstract: A method is provided for controlling electrical load on a power grid from a load facility using demand response. The method includes accessing memory storing computer-readable program code for decision analysis of a specified time interval for a demand-response (DR) event. The method also includes executing the computer-readable program code, via a processor, to cause an apparatus to at least make a decision to participate in or opt out of the DR event. This includes the apparatus receiving values of variables that describe occupancy and usage of the load facility for one or more time intervals. The apparatus applies the values to an algorithm that maps the variables to a decision to participate in or opt out of the DR event for the specified time interval. And the apparatus automatically notifies an operator responsible for the DR event of the decision at least when the decision is to opt out.

Abstract: Improvements to an HVAC thermostat include a sleep-enhancing feature which regulates the target temperature of the HVAC system according to a temperature profile which complements the natural changes in body temperature of a person during sleep. The timing of the temperature profile is advanced to cause room temperature to decrease before the natural decrease in body temperature is expected to occur, thereby helping lead a person into sleep without the use of pharmaceuticals or other artificial sleeping aids. The temperature profile causes room temperature to increase towards the end of the sleep period, thus avoiding disruptions of sleep when body temperature is lowest or during REM stages of sleep when the human body's ability to thermo-regulate is diminished. The rate of change of the target environment temperature is controlled to further enhance the quality and duration of sleep.

Abstract: Systems, apparatus and methods for operating an environmental control system that delivers dehumidified outdoor air into a conditioned space through an air valve. The method includes establishing CO2 setpoints corresponding to a ventilation outdoor air flow rate and a dehumidification outdoor air flow rate, determining a humidity metric of the conditioned space, and delivering outside air to the conditioned space at the ventilation outdoor air flow rate or dehumidification outdoor air flow rate based upon the humidity metric. The outside air may be tempered with return air from the conditioned space. The dehumidification CO2 set point is determined by predicting the dehumidification CO2 set point based on the airflow quantity per occupant and the relationship of the occupant predicted water vapor emission rate and CO2 emission rate.

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: 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 heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a first compressor having a first capacity, a second compressor having a second capacity, a condenser, an expansion device, and an evaporator fluidly connected. The first compressor and the second compressor are arranged in parallel. The first compressor includes a first lubricant sump. The second compressor includes a second lubricant sump. The first lubricant sump is fluidly connected to the second lubricant sump via a lubricant transfer conduit. A flow restrictor is disposed in the lubricant transfer conduit. The flow restrictor is configured to reduce a refrigerant flow between the first compressor and the second compressor.

Abstract: An energy generation system for converting combustible fluid from a nontraditional combustible fluid source to useable energy. The energy generation system including a fluid storage system including a compressor and at least one storage tank, the compressor configured to pressurize a combustible fluid from a combustible fluid source for storage in the one or more storage tanks; and an energy recovery system configured to receive the combustible fluid from the at least one storage tank, the energy recovery system including: a turboexpander configured to depressurize the combustible fluid received from the at least one storage tank; a motor-generator configured to input the combustible fluid as depressurized by the turboexpander, and generate electrical energy from the combustible fluid; and an organic Rankine cycle (ORC) system configured to generate electrical energy based on a temperature differential between the combustible fluid input to the motor-generator and a waste heat produced by the motor-generator.

Abstract: Multi-compressor chiller systems can be efficiently operated by determining real time efficiency curves for the compressors currently in operation, along with any compressors that may be added to address demand, and using these efficiency curves to determine changes to compressor operation to improve efficiency in meeting chiller demand. The efficiency curves can be parabolic curves. The data used to determine the efficiency curves can be obtained through operation at a variety of lift points and a variety of load points within those lift points. The efficiency curves can be solved to find intersections where there may be staging points for adding or subtracting compressors from operation to efficiently meet demand. This operation can be automated through a controller of a control system for the multi-compressor chiller system.

Abstract: Control systems and methods for control of heating, ventilation, air conditioning, and refrigeration (HVACR) systems that include cooling and one or both of heating and heat recovery can include adaptive and balanced modes for each of heating and cooling operations. The adaptive heating and cooling modes each respectively include controlling the HVACR system to achieve a target temperature for the respective heating or cooling process fluid and to unload or stop the compressor when the temperature of a the other of the cooling or heating process fluid exceeds a threshold. The balanced heating and cooling modes respectively include controlling a quantity of flow of the cooling or heating process fluids to meet balanced heating or cooling target temperatures for the respective heating or cooling process fluids and also the other of the cooling or heating process fluid.

Abstract: Architectures or techniques are presented that can facilitate automated function testing (AFT) in connection with an HVAC system or component thereof. The architectures detailed herein can facilitate creation, modification, or duplication of quiz data (e.g., a test). This quiz data can be executed in order to automatically test the function of the HVAC system or component. Additionally, prior to execution, a verification procedure can be performed to ensure that an expected state indicated in the quiz data can in fact be exhibited by the device. Further, execution of the quiz data can include an exit condition that, when satisfied can cause termination of the execution prior to completion. Such can be useful to avoid potentially dangerous situations or to avoid undue disruption to a service provided by the HVAC system.

Abstract: Refrigeration systems with a purge for removing non-condensables from the refrigerant and an acid filter for remove acid from the refrigerant are provided. The acid filter can be operatively connected to the purge. Optionally, the purge can include a separating device for separating non-condensable gases from condensable refrigerant gases and an acid filter is provided to remove acid from the condensable refrigerant gases.

Abstract: A bolted hinge assembly is provided for a waterbox cover (a “waterbox hinge assembly”). The waterbox hinge assembly generally does not require welding on the waterbox cover or the heat exchanger in an HVAC system (“HVAC unit” hereinafter). Further, the waterbox hinge assembly may be installable to the HVAC unit without removing the heat exchange fluids (e.g., water, refrigerant, etc.) from the HVAC unit. In some cases, the waterbox hinge assembly can be installed on an HVAC unit without removing any bolts from the waterbox cover. Once installed, the waterbox hinge assembly can be left in place so that it can be reused anytime the HVAC unit is serviced.

Abstract: Methods and related systems for operating a furnace are disclosed. In an embodiment, the method includes activating a burner assembly and a first fan of the furnace to combust fuel and air and circulate combustion gases along a flow path extending through a heat exchanger of the furnace. In addition, the method includes operating a second fan of the furnace to circulate air across an external surface of the heat exchanger of the furnace and produce a conditioned airflow. Further, the method includes monitoring one or more parameters of a motor of the second fan indicative of an airflow rate of the conditioned airflow, and deactivating the burner assembly, whereby combustion of the fuel and air in the furnace ceases, in response to the one or more parameters indicating that the airflow rate is less than a minimum airflow rate.

Abstract: Embodiments of systems and methods for power demand management are described herein. More specifically, embodiments comprise systems and methods for powering, controlling, and/or operating various types of controllable load for integration with power fluctuations from intermittent power generation plants, such as photovoltaic arrays and wind turbine farms.

Abstract: Systems and methods are provided for controlling compressor systems to ensure sufficient pressure differentials to provide cooling. A compressor system includes a compressor, a suction pressure sensor at a suction of the compressor, a discharge pressure sensor, a condenser, an expansion device, a liquid line, a liquid line pressure sensor, an evaporator, a condenser blower and a controller. The method includes determining a pressure target based on an intermediate pressure within the compressor and a threshold cooling differential pressure value, determining a pressure ratio setpoint based on the pressure target and a liquid line pressure measured by the liquid line pressure sensor, controlling the condenser blower to operate based on the determined pressure ratio setpoint, determining a subcooling setpoint based on the pressure target and the liquid line pressure in the compressor system, and controlling the expansion device to operate based on the subcooling setpoint.

Abstract: A gas bearing for a compressor includes a bearing portion and a sealing portion mounted to a bearing housing of the compressor via one or more dampers, and the sealing portion being fixedly connected to the bearing portion, and a vent with an inlet in the bearing. The bearing portion has an inner radial surface for radially supporting a shaft of the compressor. The sealing portion has a sealing surface. The inlet of the vent disposed between the inner radial surface and the sealing surface. The sealing surface and a rotating surface form a path that extends along the sealing surface. The path extending from a pressurized volume of the compressor to the vent, and the pressurized volume containing a fluid.

Abstract: A centrifugal fan for use as a blower in a heating, ventilation, air conditioning, and refrigeration (HVACR) system has a plurality of blades each having a leading edge camber angle of at or about 10 degrees to at or about 30 degrees, a trailing edge camber angle of at or about 10 degrees to at or about 30 degrees, a stagger angle of at or about 35 degrees to at or about 55 degrees, and a chord having a length L, wherein the length L over the diameter of the centrifugal fan divided by the diameter D satisfies the inequality 0.25?L/D?0.42. The fan blades having these parameters provide improved fan efficiency at certain operating conditions. The fan blades may further have a forward or radial sweep. The fan blades may have a uniform thickness from the leading edge to the trailing edge.

Abstract: Apparatus, systems and methods for ascertaining the occupancy of a building are presented. The building is divided into one or more control zones which correspond to physical areas of the building associated with controllable modules, such as HVAC units, lighting, irrigation, or other environmental features such as fountains, music, video, and the like. Zone parameters define how zone devices shall react to the number of occupants located in the particular zone. A building control system detects individual mobile devices in and around the building, and determines the locations of each device by using trilateration and/or location services. The identified mobile devices act as proxies for building occupants. The locations of these devices are correlated with the locations of the zones in the building, and the building control system then adjusts the operating parameters of the zone based on the number of devices present in the zone.

Abstract: A compressor includes a housing, a shaft, and an impeller rotatable relative to the housing by the shaft. The impeller includes a hub, impeller blades, and external blades. The impeller blades extend from a front of the hub. The external blades protrude from a rear surface of the hub or an outer surface of a shroud of the impeller. The external blades are curved along the rear surface or the outer surface. A heat transfer circuit includes a compressor and a working fluid. The compressor includes an impeller having a hub, impeller blades, and external blades.