A refrigerant cycle apparatus includes a refrigerant circuit that circulates a refrigerant, and a leak sensor that detects a refrigerant leaking from the refrigerant circuit, in which the refrigerant cycle apparatus includes, as an operating mode, a recovery mode for recognizing occurrence of an abnormality in the leak sensor and recovering a refrigerant to a predetermined location in the refrigerant circuit.

A smart sound appliance which has a noise producing device such as a compressor that is controlled by a controller. The controller receives information from a user indicative of whether the user is in a location to receive those sounds. When the user is in the location to receive those sounds, the controller can take an action to reduce those sounds by either turning off the compressor, or reducing the sound of the appliance in some other way.

A method for controlling a vapour compression system (1) including two or more evaporators (5, 12), each evaporator (5, 12) being arranged in thermal contact with a refrigerated volume, the refrigerated volumes storing goods of various types, and each evaporator (5, 12) receiving refrigerant via an expansion device (6, 13) is disclosed. In response to receipt of a load shedding command originating from a power grid (17), the vapour compression system (1) reduces a compressor capacity of the compressor unit. The refrigerated volumes are divided into at least two prioritized categories of refrigerated volumes, where a first category (18) includes refrigerated volumes storing goods of a temperature critical type, and a second category (19) includes refrigerated volumes storing goods of a temperature non-critical type. Refrigerant supply to the evaporator(s) (5, 12) being in thermal contact with the refrigerated volume(s) of the second category (19) is discontinued, and refrigerant supply to the evaporator(s) (5, 12) being in thermal contact with the refrigerated volume(s) of the first category (18) is continued. Thereby the vapour compression system (1) is capable of providing load shedding services for an extended period of time without compromising temperature critical storage.

A plurality of scroll compressors with different fixed volume indexes are connected in fluid parallel circuit and configured to selectively operate to maximize isentropic efficiency at different condensing temperatures. Different quantities of scroll compressors of different volume indexes may be selected based upon typical climate or geographic location environmental conditions to attempt to maximize efficiency. A controller may selectively operate different combinations of the compressors of different volume indexes bases up load demands and condensing temperature conditions, which may be determined in a variety of ways.

A system for modulating hot gas reheat operation of a heating, ventilation, and/or air conditioning (HVAC) system with multiple compressors, wherein the HVAC system is configured to regulate air provided to multiple zones. The system includes a controller configured to respond to a call for dehumidification in the absence of a call for cooling by sequentially energizing a first compressor of the multiple compressors in a reheat mode of the first compressor, energizing a second compressor of the multiple compressors in a cooling mode of the second compressor, energizing a third compressor of the multiple compressors in a reheat mode of the third compressor initially at full capacity, and energizing a fourth compressor of the multiple compressors in a cooling mode of the fourth compressor.

An HVAC system includes a compressor, condenser, and evaporator. A sensor measures a value associated with the refrigerant in the condenser or the evaporator, and a controller is communicatively coupled to the compressor and the sensor. The controller determines, based on an operational history the compressor, that pre-requisite criteria are satisfied for entering a sensor validation mode. After determining the pre-requisite criteria are satisfied, an initial sensor measurement value is determined. Following determining the initial sensor measurement value, the compressor is operated according to a sensor-validation mode. Following operating the compressor according to the sensor-validation mode for at least a minimum time, a current sensor measurement value is determined. The controller determines whether validation criteria are satisfied for the current sensor value. In response to determining that the validation criteria are satisfied, the controller determines that the sensor is validated.

A refrigeration system configured to receive a refrigerant is provided, as well as a walk-in refrigeration unit configured to utilize said system. The refrigeration system comprises: a power source, a condenser unit, an evaporation unit, a plurality of compressors, wherein each of the plurality of compressors is communicably coupled to the condenser unit, and a plurality of expansion devices, wherein each of the plurality of expansion devices is communicably coupled to the evaporation unit. The system is configured to receive an A3 refrigerant having a Global Warming Potential (GWP) value less than 10.

A test chamber and a method for conditioning air in a temperature-insulated test space of a test chamber, which is sealable against an environment and serves for receiving test material, a temperature ranging from −20° C. to +180° C. being produced within the test space by means of a cooling device of a temperature control device of the test chamber, using a cooling circuit with carbon dioxide (CO.sub.2) as a cooling agent, using a heat exchanger in the test space, using a low-pressure compressor and using a high-pressure compressor downstream of the low-pressure compressor, using a gas cooler, using a storage means for the cooling agent and using an expansion valve, the temperature in the test space being controlled and/or regulated by means of a control device of the test chamber. A gaseous and/or liquid cooling agent is dosed in the storage means by means of a high-pressure valve of the cooling circuit downstream of the gas cooler, the storage means being connected to a medium-pressure side of the cooling circuit upstream of the high-pressure compressor and downstream of the low-pressure compressor via a medium-pressure bypass of the cooling circuit, the gaseous cooling agent being dosed in the medium-pressure side from the storage means by means of a medium-pressure valve when the low-pressure compressor is switched off.

A monitoring and/or control device for an environmental control unit such as a heat pump determines the performance status and whether maintenance is required of a component of the unit for example a compressor during operation of the component. The device includes sensors configured to be situated relative to the compressor so as to receive and signal data from the compressor during operation of the component. In some embodiments, the device includes a vibration detector and a controller coupled to the vibration detector. The controller is configured to (i) receive electrical signals from the vibration detector, (ii) compare the electrical signals to a reference signal, (iii) determine the performance characteristic of the component based on the results of the comparison, and (iv) output a signal corresponding to the performance characteristic of the component to a user display. The controller may also request maintenance and/or order parts automatically.

A refrigeration cycle device includes: a switching valve configured to switch between a battery mode in which refrigerant flows to a battery heat exchanger and a non-battery mode in which the refrigerant bypasses the battery heat exchanger; and a controller controlling a compressor and the switching valve. The controller includes an estimation unit configured to estimate an oil stagnation amount, which is an amount of lubricating oil accumulated in the battery heat exchanger in accordance with execution of the non-battery mode. The controller includes a determination unit configured to determine whether lubricating oil in the battery heat exchanger needs to be recovered on the basis of the oil stagnation amount. The controller includes an execution unit configured to execute an oil recovery mode for recovery of lubricating oil in the battery heat exchanger when the determination unit determines that lubricating oil needs to be recovered.