Abstract: The present invention relates to a method for the determination of the coefficient of performance of a refrigeration machine, in particular of a heat pump, which includes a closed circuit which has a refrigerant and in which an evaporator, a compressor, a condenser and an expansion valve are arranged. In the method, at least three temperatures of the refrigerant are determined using temperature sensors arranged in the circuit. Alternatively, at least two temperatures and at least one pressure of the refrigerant is determined using sensors arranged in the circuit. Enthalpies of the circuit are calculated from the determined refrigerant temperatures and refrigerant pressures and the heat output and the taken up electrical power of the refrigeration machine are calculated therefrom to determine the coefficient of performance of the refrigeration machine from the quotient of the calculated heat output and the calculated taken up electrical power.

Abstract: A system comprises a condenser for a refrigeration system and a control module. The condenser has a plurality of variable speed condenser fans. The control module controls the plurality of variable speed condenser fans. The control module increases condenser fan operation by activating a deactivated variable speed condenser fan at a first fan speed when at least one variable speed condenser fan of the plurality is deactivated and by increasing a fan speed of an activated variable speed condenser fan to a second fan speed when each variable speed condenser fan of the plurality is activated and operating at the first fan speed. The second fan speed is faster than the first fan speed.

Abstract: A method comprises monitoring an operating parameter of a refrigeration system that includes a first condensing unit having a first control module and a second condensing unit having a second control module, the first and second condensing units each having at least one compressor. The method also includes controlling, with the first control module, the at least one compressor of the first condensing unit based on the monitoring. The method also includes controlling, with the first control module, the at least one compressor of the second condensing unit based on the monitoring. The first control module controls the at least one compressor of the second condensing unit by communicating with the second control module via a communication link.

Abstract: A refrigeration system comprises a plurality of compressors and a plurality of condensing units comprising a first condensing unit having a first control module and at least one additional condensing unit having an additional control module. Each condensing unit has at least one compressor of the plurality of compressors. A communication link is connected to the first control module and at least one additional control module. The first control module controls the plurality of compressors based on communication with the at least one additional control module via the communication link.

Abstract: The present invention relates to a method for the determination of the coefficient of performance of a refrigeration machine, in particular of a heat pump, which includes a closed circuit which has a refrigerant and in which an evaporator, a compressor, a condenser and an expansion valve are arranged. In the method, at least three temperatures of the refrigerant are determined using temperature sensors arranged in the circuit. Alternatively, at least two temperatures and at least one pressure of the refrigerant is determined using sensors arranged in the circuit. Enthalpies of the circuit are calculated from the determined refrigerant temperatures and refrigerant pressures and the heat output and the taken up electrical power of the refrigeration machine are calculated therefrom to determine the coefficient of performance of the refrigeration machine from the quotient of the calculated heat output and the calculated taken up electrical power.

Abstract: The invention relates to a control unit for a refrigeration or air conditioning device, comprising a main processor that is situated in a housing and that controls the temperature, fan and/or the defrosting process of a refrigeration or air conditioning device. Contact points for a co-processor, which is separate from the main processor and is suitable for controlling an electronic expansion valve, are located in said housing.

Abstract: The invention relates to a control unit for controlling the expansion valve of a refrigeration or air conditioning system, comprising a temperature sensor that is connected upstream of the expansion valve in the coolant circuit. If the control unit detects a decrease in temperature of the aforementioned temperature sensor, which is generally caused by the start of a defrosting process, it displaces the expansion valve into a static state, to protect said valve during the defrosting process.

Abstract: A refrigeration system comprises a plurality of compressors and a plurality of condensing units comprising a first condensing unit having a first control module and at least one additional condensing unit having an additional control module. Each condensing unit has at least one compressor of the plurality of compressors. A communication link is connected to the first control module and at least one additional control module. The first control module controls the plurality of compressors based on communication with the at least one additional control module via the communication link.