Abstract: A life safety device includes a housing, a detector for detecting one or more conditions, and an actuatable mechanism coupled to the housing. The actuatable mechanism includes a light assembly operable in response to detection of at least one of the one or more conditions.

Abstract: A refrigerant vapor compression system includes a compression device having at least a first compression stage and a second compression stage arranged in series refrigerant flow relationship. A first refrigerant heat rejection heat exchanger is disposed downstream with respect to refrigerant flow of the second compression stage. A first refrigerant intercooler is disposed intermediate the first compression stage and the second compression stage. The first refrigerant intercooler is disposed downstream of the first refrigerant heat rejection heat exchanger with respect to the flow of the first secondary fluid. An economizer includes a vapor line in fluid communication with a suction inlet to the second compression stage. A second refrigerant heat rejection heat exchanger is disposed intermediate with respect to refrigerant flow of the second compression stage and the first refrigerant heat rejection heat exchanger.

Abstract: A method of shutting down a refrigeration system including: initiating a shutdown process of the refrigeration system; closing a first valve within a refrigerant circuit of the refrigeration system; operating a compressor within the refrigerant circuit; detecting a suction pressure within the refrigerant circuit; closing a second valve within the refrigerant circuit of the refrigeration system when the suction pressure is below a threshold suction pressure; and stopping operation of the compressor.

Abstract: A transport refrigeration unit for use with a transport trailer includes a structural framework mountable to a wall of the transport trailer, a condenser heat exchanger unit mounted to the structural framework, an evaporator housing separated from the condenser heat exchanger by a distance, and at least one condenser fan assembly positioned aft of the condenser heat exchanger unit and forward of the evaporator housing. The at least one condenser fan assembly includes a fan rotor defining an inlet end. The fan rotor is rotatable about a fan axis. A casing defines a central opening and the fan rotor is arranged within the central opening. The casing includes a plurality of openings spaced about a periphery of the casing. A portion of an airflow moving through the at least one condenser fan assembly is expelled from the at least one condenser fan assembly radially via the plurality of openings.

Abstract: A communication system includes a master unit; and a plurality of slave units including a slave unit to which a termination resistance is set, the plurality of slave units connected to the master unit via a communication line. In the communication system, the master unit includes a master communication control unit that normally sets a communication rate of communication performed with the plurality of slave units to a high baud rate, switches the high baud rate to a low baud rate after detecting that communication with the slave unit to which the termination resistance is set is disabled, transmits an instruction for switching the low baud rate to the high baud rate to the plurality of slave units after detecting that the communication with the slave unit to which the termination resistance is set is restored, and switches setting of the master unit itself to the high baud rate.

Abstract: A method of calibrating an optical detector includes installing a calibration system within at least one sensing volume of the optical detector, filling a chamber of the calibration system with a material to achieve a known obscuration, and measuring an obscuration of the material within the chamber.

Abstract: A sensor and a method of using the sensor are disclosed. The sensor includes a conductive region in electrical communication with two electrodes, the conductive region including a MXene material combined with a mercaptoimidazolyl metal-ligand complex, wherein the MXene has the formula Mn+1Xn and M is at least one of a Group 3 transition metal, Group 4 transition metal, Group 5 transition metal, and Group 6 transition metal, X is carbon, nitrogen or a combination thereof, and n has a value of 1 to 3. The sensor can be used to detect volatile compounds that have a double or triple bond.

Abstract: A regional lock-state control system for operation within a region, includes a server, a plurality of mobile devices and a plurality of lock assembles. The server is configured to initiate a lock-state event. The mobile devices are each configured to receive a wireless lock-state directive from the server upon the lock-state event, and send a wireless lock lock-state directive to the server. The lock assemblies are each configured to receive a lock-state command associated with the lock-state directive from the plurality of mobile devices, and are each configured to transmit an advertisement that includes data on a lock-state.

Abstract: A control method for a centrifugal compressor and an air conditioning system. The control method for the centrifugal compressor includes: S100, when an inlet opening of the centrifugal compressor is below a first preset value, shutting down a drive motor of the centrifugal compressor; or S200, when the inlet opening of the centrifugal compressor is not below the first preset value, performing the following operations in a preset order: decreasing the inlet opening of the centrifugal compressor, and increasing a rotate speed of the centrifugal compressor.

Abstract: An example screening system includes a plurality of detectors about a screening area. Each detector includes a sensor configured to detect information from one or more objects moving along a path from an entrance to an exit of the screening area. The plurality of detectors include a first detector configured to detect information from a first location of the path, and a second detector configured to detect information from a second location of the path. The second detector is configured to adapt its functionality based on a finding of the first detector for a given one of the one or more objects.

Abstract: A method of making an electrocaloric article is disclosed. The method includes mounting a supported electrocaloric film to a frame. The supported electrocaloric film includes an electrocaloric film and a first support film disposed on a first side of the electrocaloric film. An active area of the electrocaloric film is provided, which is not covered by the first support film on the first side of the electrocaloric film. Electrical connections are provided to electrodes disposed on opposing sides of the electrocaloric film in the active area.

Abstract: A fire system for a building is provided, the fire system including a fire panel for monitoring the building and activating an alarm; and a plurality of remote units electrically connected to the fire panel in a circuit having a loop configuration. At least some of the plurality of remote units including an indicating device for modulating a current in the circuit. The plurality of remote units are in communication with the fire panel in a master-slave relationship. The fire panel includes a calibration module for polling each indicating device to obtain a current response value and for storing said current response values, the current response value of an indicating device being based on the amplitude of the current when modulated by that indicating device.

Abstract: A method of operating a refrigeration system is provided. The method includes activating an evaporator heater, monitoring a pressure differential within the refrigeration system, when the pressure differential reaches a predetermined value, deactivating the evaporator heater, and activating one or more evaporator fans, after deactivating the evaporator heater, to cause a thermostatic expansion valve to open.

Abstract: Provided are techniques for integrating a body camera with a locking mechanism. The techniques include assigning a body camera to a user and detecting a proximity of the body camera to a locking mechanism. The techniques also include determining a state of the locking mechanism, and automatically triggering recording of the body camera based at least in part on the proximity and the state of the locking mechanism.

Abstract: A method of assembling a fan wheel includes forming a first wheel portion including a first plurality of impeller blades and a first connector, forming a second wheel portion including a second plurality of impeller blades and a second connector, affixing an end of each of the first plurality of impeller blades to a first surface of a support ring such that the first connector is affixed to the second connector, and affixing an end of each of the second plurality of impeller blades to a second surface of a support ring.

Abstract: A system and method for controlling a heating, ventilation, and air-conditioning (HVAC) system is provided. Aspects include receiving, from a sensor, operational data associated with the HVAC system, receiving, from the sensor, environmental data associated with the HVAC system, analyzing the operational data and the environmental data to determine a potential comfort issue with the HVAC system, receiving a discomfort index associated with the HVAC system, plotting an indicia on the discomfort index based on the operational data and the environmental data, and determining a root cause of the potential comfort issue based at least in part on a coordinate of the indicia on the discomfort index.

Abstract: A centrifugal compressor and a method of operating a centrifugal compressor. The centrifugal compressor includes: an impeller configured to suction a gas to be compressed; a diffuser disposed downstream of the impeller to pressurize the gas, the diffuser comprising a movable ring, a main passage in which the gas flows past the ring, and an openable branch passage; and a circulation loop comprising an inlet and an outlet, the outlet being in communication with an inlet of the impeller; the branch passage is disposed to be in communication with the main passage and the circulation loop when the ring moves into the main passage so that a portion of the gas in the main passage passes through the circulation loop and returns to the impeller so as to be suctioned, and to be closed when the ring is withdrawn from the main passage.

Abstract: An event notification system includes a wireless device, an Access Point device, a server, and a user application. The server is configured to receive a plurality of heartbeats from the wireless device and through the Access Point device, and send a heartbeat response of a plurality of heartbeat responses in response to a respective heartbeat of the plurality of heartbeats. The user application is configured to send enable and disable commands to the server. The enable command is sent to the wireless device as part of the next heartbeat response of the plurality of heartbeat responses. The disable command is sent to the wireless device after the server receives an event condition from the wireless device through the AP device.

Abstract: A compact heat exchanger assembly for a refrigeration system includes a heat rejection heat exchanger assembly and a heat absorption heat exchanger assembly. The heat rejection heat exchanger assembly includes a primary heat exchanger and a secondary heat exchanger. The primary heat exchanger has a tube bank extending between a first manifold and a second manifold. The tube bank being provided with at least one bend such that the primary heat exchanger has a generally curvilinear shape. The secondary heat exchanger is disposed between the first manifold and the second manifold.

Abstract: An oil separator is provided and includes an exterior shell defining a first interior and first and second openings fluidly communicative with the first interior, a distributor and first and second filter media cartridges. The distributor is integrated within the exterior shell to define a second interior within the first interior, has a length, which is slightly less than that of the exterior shell, being disposed to define opposite spaces between opposites ends thereof and opposite ends of the exterior shell and is sealed to the exterior shell along the length to form first and second passageways from the first opening to the opposite spaces. The first and second filter media cartridges are disposed within the first interior between the opposite spaces and the second opening.