Abstract: A refrigerator includes an ice maker positioned in the refrigerator and configured to make ice. The refrigerator also includes a plate positioned at an open side of the ice making tray and configured to reduce water overflow. The refrigerator further includes a cool air inlet passage configured to allow cool air to be introduced to an area inside of the plate. In addition, the refrigerator includes a cool air outlet passage that is separate from the cool air inlet passage, and configured to allow release of cool air from the area inside of the plate to an exterior of the plate.

Abstract: A control unit including a switch for regulating the temperature of a passenger compartment and/or the temperature of a vehicle seat. The switch is of a unit type with a control member, a switch member, a light-emitting member, and an indicator member housed in a single case, and can be disposed anywhere near a driver.

Abstract: A compressor is controlled by generating and storing a compressor operation log. In addition, a compressor operation is selected from the compressor operation log in response to a sensor failure. Furthermore, the compressor is modulated according to the selected compressor operation in response to the sensor failure.

Abstract: A temperature control system includes a compressor, a condenser, an evaporator, and an accumulator. A liquid level sensor is associated with the accumulator tank generates a signal indicative of the level of the liquid heat transfer fluid inside the accumulator. A valve is in fluid communication with the condenser, the compressor, and the evaporator and is operable in a first position and a second position. The first position directs the heat transfer fluid from the compressor to the condenser, and the second position directs the heat transfer fluid from the compressor to the evaporator without passing through the first heat exchanger. A controller is in electrical communication with the liquid level sensor and the valve and is operable to receive the signal and move the valve from the first position to the second position based on the signal.

Abstract: A method and a device for detecting flash gas in a vapor-compression refrigeration or heat pump system comprising a compressor, a condenser, an expansion device, and an evaporator interconnected by conduits providing a flow path for a refrigerant, by determining a first rate of heat flow of a heat exchange fluid flow across a heat exchanger of the system and a second rate of heat flow of the refrigerant across the heat exchanger, and using the rates of heat flow for establishing an energy balance from which a parameter for monitoring the refrigerant flow is derived, to thereby provide early detection of flash gas with a minimum number of false alarms.

Abstract: A method of venting a refrigerant from an air conditioning system of a vehicle during a crash to mitigate leakage of the refrigerant into a cabin of the vehicle by crashing a test vehicle under a first set of predetermined conditions a number of crash events and measuring deceleration and determining the existence of leakage. The number of crash events in which leakage existed is divided by the number of crash events to establish a probability of leakage ratio. The test vehicle is crashed under a second set of predetermined conditions to determine a second probability of leakage ratio. A probability of leakage relationship is established correlating the probability of leakage ratios and the predetermined conditions. A deceleration relationship is established correlating the deceleration measurements and the predetermined conditions.

Abstract: Methods and apparatus are provided for determining refrigerant charge in a vapor compressor system (VCS) of an aircraft. The methods and apparatus comprise the following steps of, and/or means for, generating a data set from historical data representative of a plurality of VCS operating conditions over time, identifying one or more steady-state data points in the generated data set, forming a revised data set that includes at least the steady-state data points, using principal components analysis (PCA) to derive values for a plurality of minimally correlated input variables, supplying the derived values for the plurality of minimally correlated input variables and the corresponding values for the VCS refrigerant charge in the revised data set to a nonlinear neural network model, and deriving a simulator model characterizing a relationship between the plurality of minimally correlated input variables and the VCS refrigerant charge.

Abstract: A method, apparatus, and computer usable program product for identifying an optimal placement of an item within a storage unit. The process identifies an item for placement in the storage unit. The process determines a preferred storage temperature range for the identified item. The process then selects an optimal placement location within the storage unit for the identified item based on the preferred storage temperature range and a set of temperature readings for the storage unit.

Abstract: In concurrent operation of performing a refrigeration cycle in which an outdoor heat exchanger (22) functions as a condenser, and at least one of a plurality of indoor heat exchangers (31, 41, 51) functions as a condenser, pressure difference ?P1 between a high pressure refrigerant an a refrigerant in a liquid pipe (15) is detected, and the degree of opening of an outdoor expansion valve (23) is adjusted so that the pressure difference ?P1 becomes larger than a predetermined target value.

Abstract: A method of proofing a refrigeration system operating state includes monitoring a change in operating state of a refrigeration system component, determining an expected operating parameter of the refrigeration system component as a function of the change, and detecting an actual operating parameter of the refrigeration system component after the change. The method also comprises comparing the actual operating parameter to the expected operating parameter of the refrigeration component and detecting a malfunction of the refrigeration system component based on the comparison. The method may be executed by a controller or stored in a computer-readable medium.

Abstract: An innovative oil observer for estimating oil concentration and oil amount in a refrigerant compressor in a vapor compression cycle is described. The invention ensures the safe operation of the compressor by ensuring that adequate lubricant is present in the compressor. This oil observer is based on oil models for components of air conditioning and refrigeration systems. Oil models for HVAC components estimate oil mass and refrigerant mass in each component. With all component oil models and heat exchanger observers which provide the estimation of inner geometric lengths of two-phase flow heat exchangers, a system-level oil observer is established by integrating all component models. Experimental testing has been conducted to verify the performance of this oil observer for steady state operation and dynamic processes. The invention has direct applications in residential and commercial air conditioning and refrigeration systems.

Abstract: The present invention relates to an ice maker-driving device for a refrigerator and a method for operating the same wherein the ice-making container connected to the ice-separating lever and rotated by initial circuit set is reversely rotated before forward rotation and has a protruded coupling part having a predetermined angle formed on the other side thereof, without any cooperation with the ice-separating lever, so as to be coupled with a case-fixing part, thereby allowing the ice-making container to be twistedly rotated at one side thereof according to the reverse rotation of the ice-separating lever, such that the separation of ice cubes is conducted and also the stress and tense state of the parts caused by their freezing are removed to prevent their malfunction, thereby efficiently achieving the ice-separating and storing operations.

Abstract: Disclosed is a method for evaluating a non-measured operating variable in a refrigeration plant, which can be derived from at least one signal which is sensed at specific points in time, enabling early recognition of errors. An error indicator is formed by means of the following steps: a) the error indicator is set to a specified value at a first moment in time; b) a sum if formed from the error indicator of a predetermined earlier moment in time and a first variable derived from an estimated value for the operating variable taking into account at least one signal-dependent variable; c) the error indicator is set to the value of the sum if the sum is greater than the specified value, and set to the specified value if the sum is less than or the same as the specified value.

Abstract: In order to not risk producing an overpressure of air in the cabin of an airplane on the ground during servicing operation on the airplane, it is appropriate to deliver the air into the cabin of the airplane only when the inlets of the air-conditioning system are open. A device for feeding electricity and air to an airplane on the ground includes means of electric production capable of being connected to at least one electric circuit of the airplane and includes means of producing a flow of air. It has, in addition, a means of determining whether the airplane is actually switched on electrically or is not actually switched on electrically and means for inhibiting the flow of air delivered toward the airplane when the airplane is not actually switched on electrically, that is, as long as it is uncertain whether the inlets of the air-conditioning system are opened.

Abstract: An apparatus for controlling a refrigerant level comprises a first detecting unit installed at a lower side of the inside of a refrigerant tank, for detecting whether a refrigerant stored at a lower side of the inside of the refrigerant is a liquefied refrigerant or a gaseous refrigerant, a second detecting unit installed at an upper side of the inside of the refrigerant tank, for detecting whether a refrigerant stored at an upper side of the inside of the refrigerant tank is a liquefied refrigerant and a gaseous refrigerant, and a control unit controlling intake and discharge of the liquefied refrigerant according to a value measured by the first detecting unit and the second detecting unit.

Abstract: An air conditioner includes a main refrigerant circuit and a liquid level detection circuit. The main refrigerant circuit includes a compressor that compresses gas refrigerant, a heat source side heat exchanger, a receiver that stores liquid refrigerant, and user side heat exchangers. The liquid level detection circuit is arranged so as to be capable of drawing out a portion of the refrigerant in the receiver from a first predetermined position of the receiver, reducing the pressure of the refrigerant and heating it, measuring the temperature of the refrigerant, and then returning the refrigerant to the intake side of the compressor, in order to detect whether the liquid level in the receiver is at the first predetermined position.

Abstract: A system for monitoring and managing a refrigeration system of a remote location includes a management center in communication with a refrigeration system through a communication network. The management center receives performance information of the refrigeration system. The management center employs software modules to analyze the performance information; diagnose system conditions; provide alarms for food safety issues, food quality issues and refrigeration system component failure; indicate maintenance conditions; and configure the refrigeration system.

Abstract: A climate control device includes a first and a second thermal module. The first module is configured to provide climate conditioned air to a first portion of a seat. The second module is configured to provide climate conditioned air to a second portion of the seat. A control system is provided for controlling the climate control device. The control system includes an input device for providing a set point for the system. A first control unit of the control system is provided for the first thermal module and a second control unit is provided for the second thermal module.

Abstract: A multi-zone HVAC&R system has its control programmed to provide diagnostic testing of air handling components and refrigerant components associated with each climate controlled zone in sequence. The control changes the original position of the corresponding component and a resultant change in a relevant operational parameter is sensed. If the actual change is outside of the tolerance band associated with the expected change, then the determination is made that the component under consideration is malfunctioning. The periodicity of a diagnostic procedure for a particular component is typically defined by its criticality and reliability level. If the change in the corresponding operation parameter is recorded and stored in the database, the component degradation can be observed over time and a prognostic prediction can be made when a particular component requires preventive maintenance or replacement.

Abstract: An air conditioner having an enhanced user perception and a controlling method thereof are provided. A predetermined character and/or its applied character image are/is displayed on a display window of the air conditioner. The character and/or the character image are/is changed depending on the operational states of the air conditioner, so that the user perceives the operational state of the air conditioner more conveniently. The air conditioner has advantages in that the user can perceive the operational state of the air conditioner more conveniently, the user can be stimulated to purchase the product, and a use term of the air conditioner can be extended.

Abstract: The present invention concerns a cooling or heating system including at least a compressor (2), a condenser (4), an expansion apparatus (17A; 17B) and a vaporiser (20). The invention is characterised essentially in that in the condenser or in proximity to an outlet of the condenser (4) there is a control apparatus (7A; 7B) arranged to receive liquid from the condenser (4) and that includes an outlet to a condensate channel (9) and an intake (14; 30) to a signal channel (6, 10; 31), in that the condensate channel (9) is connected to the expansion apparatus (17A; 17B), in that there is means (8, 11, 18, 30, 34) to vaporize liquid that comes into the signal channel (6, 10; 31), in that means (12, 13) are connected to the signal channel (6, 10; 31) to control the expansion apparatus' (17A; 17B) opening process whereby said control is affected by the amount of liquid that is vaporised in the signal channel (6, 10; 31). The invention also concerns a method for controlling a cooling or heating system.

Abstract: A method and apparatus for non-invasively determining a charge level of a refrigerant in a vapor-compression cycle system. The method and apparatus monitor the system while the system is operated to ascertain that the system is operating at approximately steady-state. The superheat and the subcooling of the system are then determined at the suction line and at the liquid line, respectively, and the refrigerant charge level is calculated based on the determined subcooling, the determined superheat, and rated operating conditions of the system, including rated refrigerant charge level, rated liquid line subcooling, and rated suction line superheat.

Abstract: A predictive maintenance method and apparatus for HVACR systems including a sensor capable of detecting the presence of a gaseous phase in the refrigerant fluid at a location wherein solely liquid phase should be present if the system is functioning properly.

Abstract: Disclosed are an abnormal state detecting apparatus of a multi-type air conditioner and a method thereof. The method comprises: a user's selecting a test operation, and then detecting plural indoor temperatures of indoor zones where a plurality of indoor units are installed and plural outdoor temperatures of outdoor zones where a plurality of outdoor units are installed; selecting a corresponding test operation mode among a plurality of test operation modes preset according to an average indoor temperature of the detected plural indoor temperatures and an average outdoor temperature of the detected plural outdoor temperatures; test-operating the multi-type air conditioner according to the selected test operation mode, and collecting data showing an operation state of the test-operated air conditioner; and comparing the collected data with a preset reference data and judging an abnormal state of the multi-type air conditioner based on the comparison result.

Abstract: A cryopump is provided with: a refrigerator that generates a cold state by a heat cycle in which an operating gas inhaled inside is expanded and discharged; a heat shield thermally connected to the refrigerator so as to be cooled to a target temperature; and a control unit that determines a command value for a heat cycle frequency such that a temperature of the heat shield follows the target temperature, and provides the command value to the refrigerator. The control unit estimates whether the refrigerator outputs a refrigerating capacity corresponding to the command value for the frequency based on a flow rate of the operating gas.

Abstract: Provided is an air conditioner, particularly, an apparatus and method for controlling a super-heating degree in a heat pump system for preventing a liquid refrigerant from flowing into a compressor. The method includes: operating the heat pump system; receiving a present outdoor temperature, a pipe absorption temperature and a low pressure value of a compressor, respectively; computing a present absorption super-heating degree from a difference between the absorption temperature of the compressor and a saturated temperature at a low pressure side; and comparing an targeted absorption super-heating degree set in advance, with the computed present absorption super-heating degree according to the received outdoor temperature, and controlling the system so that the present absorption super-heating degree may follow the targeted absorption super-heating degree.

Abstract: A refrigeration unit and a respective control and management assembly, comprising a refrigeration assembly and at least one power input for its electrical power supply. The refrigeration unit comprising at least one signal input and at least one control switch, which is arranged along a power line which corresponds to the power input. The control switch controlling the power line and the data that arrive from the respective signal input being suitable for driving the control switch for consequently determining the presence/absence of electrical power supply for said refrigeration assembly.

Abstract: The present invention relates to a refrigerator, which, by means of a control unit (2) equipped with a display (2.1) on the refrigerator body (1), allows users to maintain foodstuff under ideal storage conditions, and to monitor the comprised stock without opening the refrigerator door. Under the light of detailed information recorded to the said control unit (2) by means of RF-tags or a barcode reader or wired/wireless data loading units; the conditions of refrigerator compartments as determined by foodstuff characteristics and the monitoring of stock therein are shown to users via said display (2.1) without necessitating said user to open the refrigerator door.

Abstract: A life-saving child car seat/carrier safety system that protects a child from injury or death due to passenger compartment temperature extremes is described herein. Each year, children and infants die tragically as a result of overheating in automobile passenger compartments when they are mistakenly left unattended by their caregivers. The present invention provides a system and method for child safety comprising an automatically closing child car seat compartment that detects dangerous temperatures; notifies caregivers via an auto-dialing cell phone; alerts passersby via emergency lighting, audible alarms, vocal alerts, and electronic messaging; contacts emergency services with GPS location information; provides breathable air; and provides temperature regulation as needed to cool or warm a child.

Abstract: A method and apparatus for determining the sufficiency of the refrigerant charge in an air conditioning system by use of temperature measurements. The temperature of the liquid refrigerant leaving the condenser coil and the outdoor temperature are sensed and representative electrical signals are generated. The electrical signals are converted to digital values that are than compared to predetermined optimal values to determine whether the system is properly charged with refrigerant. An appropriate LED is lighted to indicate that the system is undercharged, overcharged or properly charged. For non-TXV/EXV systems a third parameter i.e. the return air wet bulb temperature is also sensed and a representative digital value thereof is included in the comparison with the predetermined known values to determine if the charge is proper.

Abstract: The present invention relates to a refrigerator having a dispenser. In the present invention, the dispenser is provided in a concave portion of a door to be exposed toward a front surface of the door. A water tank is installed between a rear surface of the dispenser and a door liner defining a rear surface of the door. The water tank stores the water delivered from an external water supply source while the water in maintained at a relatively low temperature and then discharges the water to the outside through the dispenser. Furthermore, in the present invention, a nozzle, through which the water is discharged from the water tank, is directly connected to a drainpipe of the dispenser, so that users may always take out the water maintained at a constant temperature.

Abstract: There is provided a refrigerant system 100 including at least one or a plurality of refrigerant flow control devices 125 for regulating operational parameters of the refrigerant system 100, at least one sensor 135, 140 connected to the refrigerant system 100 for monitoring the operational parameters of the refrigerant system 100, and a controller 130.

Abstract: A refrigeration case monitoring system. In one embodiment, the refrigeration case monitoring system includes a first fiber optic cable, a second fiber optic cable, and a control system having a first sensing channel and a second sensing channel. The first fiber optic cable transmits a signal that is indicative of a refrigeration case condition. The second fiber optic cable transmits a signal that is indicative of a second refrigeration case condition. The control system receives the signals from the first and second fiber optic cables using the first and second sensing channels, processes the signals, and provides an output related to the first and second refrigeration case conditions.

Abstract: A method for monitoring compressor performance in a refrigeration system includes calculating an isentropic efficiency of a compressor of the refrigeration system, averaging isentropic efficiency over a predetermined period, comparing the average to an efficiency threshold, and detecting a compressor malfunction based on the comparison. The method may be executed by a controller or stored in a computer-readable medium.

Abstract: A method for monitoring refrigerant in a refrigeration system includes calculating a saturation temperature of refrigerant in a refrigeration system based on at least one of a discharge pressure and a discharge temperature of the refrigeration system; calculating an expected refrigerant level based on the saturation temperature; comparing the refrigerant level with the refrigerant level threshold; and generating a leak notification when the receiver refrigerant level is less than the refrigerant level threshold. The method may be executed by a controller or stored in a computer-readable medium.

Abstract: A refrigerant system utilizes environmentally friendly natural refrigerant such as carbon dioxide. A pressure relief mechanism such as pressure relief valve is incorporated into the refrigerant system design to allow for at least some amount of refrigerant to be released to atmosphere to provide safe operation or comply with agency regulations if pressure within the refrigerant system exceeds a certain limit. This release can occur during refrigerant system storage, transportation or operation. A detection device such as an electrical circuit is included into the refrigerant system design to provide an indication that pressure relief valve has opened, such that the determination can be made by a refrigerant system control or an operator whether the refrigerant system needs to be recharged and whether it can continue its normal operation, narrow its operational envelope or shut down until the refrigerant charge can be restored.

Abstract: The apparatus provides a food storage and presentation mechanism, which preserves the food stuff and provides a handy way to take out the desired amount of food when necessary, where by the food stuff is stored in cartridges positioned in a housing. The cartridges can easily removed from their receiving slots and can be filled with food/food stuff. Furthermore, the apparatus allows liquid drinks such as fruit juice etc. to be taken out of the unit without taking the box out by positioning the said box packages, which allows the self packages of the drinks to be used.

Abstract: A defrost indicator is configured such that the process of freezing and defrosting the defrost indicator places the defrost indicator into a state that is not completely reversed by refreezing, so that one can detect whether the defrost indicator defrosted and refroze or never defrosted by observing its current state. In an embodiment, the defrost indicator is initially placed in a first state before being frozen (e.g., upside down with fluid in an upper chamber). Freezing the defrost indicator places it in a second state (e.g., with the fluid frozen in the upper chamber). Then when the defrost indicator is defrosted, the defrost indicator is placed into a third state that is different than the first state (e.g., right-side-up with liquid fluid in the lower chamber). If the defrost indicator is again frozen, the defrost indicator is placed into a fourth state (e.g., the fluid frozen in the lower chamber).

Abstract: A climate controller is mounted to a wall having an exterior surface. The climate controller includes a mounting bracket recessed within the wall and having a cavity therein. A faceplate is mounted to the mounting bracket and has an opening aligned with the cavity and wherein the face place is juxtaposed the exterior surface of the wall. A control module is positionable within the mounting bracket and wherein the control module comprises a control panel. When the control module moves in a first direction, the control panel is accessible through the opening in the faceplate. When the control module moves in an opposite direction, the control panel concealed from view through the opening and a visual impact of the climate controller in relation to the wall is minimized.

Abstract: A door mounted dispenser for a refrigerator includes rear and opposing side walls that collectively define a cavity, a release mechanism for dispensing ice and/or water and a light for illuminating the cavity. The cavity light can be operated in one of three distinct modes, i.e., in a first mode wherein the cavity light is continuously illuminated, in a second mode wherein the cavity light is illuminated only through activation of the release mechanism, and in a third mode wherein the cavity light is illuminated based upon a sensed level of ambient light present at or near the refrigerator. In the third mode, the cavity light is illuminated at a first level based upon ambient light and a second, higher level when the release mechanism is operated. The level of ambient light necessary to activate the cavity light can be set by a consumer through control panel inputs.

Abstract: An electrostatically atomizing device includes an emitter electrode, an opposed electrode opposed to the emitter electrode, and a cooling means which condenses the water on the emitter electrode from within the surrounding air, and a high voltage source applying a high voltage across the emitter electrode and the opposed electrode to electrostatically charge the water for atomizing charged minute water particles from a discharge end of the emitter electrode. The device further includes a controller for discharging the charged minute water particles in a stable manner. The controller monitors a discharge current flowing between the two electrodes to control the cooling means for keeping the discharge current at a predetermined level, thereby regulating the atomizing amount of the charged minute particles from the emitter electrode.

Abstract: A manifold gauge set has at least one sight glass window for viewing contents of a refrigeration system or an air conditioning system being serviced. The window may be non-planar to achieve an appearance that varies with the presence or absence of liquid. Such a non-planar window may be in the form of a dome, prism or a fresnel lens. The gauge set may have a second light transmissive window to allow light to illuminate system contents being viewed. A light source may be provided to illuminate system contents being viewed. The light source may provide light through the same window that is used for viewing contents. A diffuser may be provided with a second window to achieve an illuminated background for viewing system contents. Similar configurations may be used in standalone sight glasses, vacuum pumps, and recovery machines.

Abstract: A method and apparatus is disclosed for detecting the ineffectiveness or failure of a fan that is used to cool an electronic device. The method and apparatus use temperatures measured before and after the fan is energized to determine if the temperature trend is affected by the operation of the fan. If the trend is not substantially affected by the operation of the fan, it is determined that the fan is not operating effectively and the user may be notified.

Abstract: A refrigerator is provided in which a communication pad is installed in one of the doors to open and close storage spaces formed in a refrigerator main body. The communication pad is detachably installed in a seating space of the door. While an upper end of the communication pad is seated in the seating space by an upper clamp, a lower end of the communication pad is seated in the seating space by a lower clamp. The upper clamp and the lower clamp are installed in the seating space through hinge assemblies. The hinge assemblies are configured so that the upper and lower clamps rotate only by a force of a predetermined value or higher. With such structure, die communication pad may be securely mounted to and easily dismounted from the door.

Abstract: A fill level measuring device for measuring the fill level of liquid food in a container is provided which includes a sensor unit and a processing unit. The processing unit being is connected to the sensor unit and embodied such that the processing unit determines the fill level of the liquid food in the container depending on the measuring signals of the sensor unit, with the sensor unit comprising a container pressure sensor. The container pressure sensor is effectively connected with the liquid food in the container in order to measure the fluid pressure of the liquid food in the container and the processing unit is embodied such that it determines the fill level of the liquid food in the container depending on a difference of the fluid pressure measured in reference to the environmental pressure.

Abstract: The sufficiency of refrigerant charge in an air conditioning system is determined by a comparison of two sensed temperatures in the system, one being the liquid line temperature and the other being either the outdoor temperature or the condenser coil temperature. In one embodiment the two sensed temperatures are displayed on respective thermochromic strips which are so calibrated and juxtaposed as to provide a visual indication, by the relative positions of the two displayed sensed temperatures, as to whether the refrigerant charge is adequate. In another embodiment, the sensed liquid line temperature is displayed by way of a plurality of LEDs and the other temperature is displayed by way of a marker on a temperature scale. If the two displayed temperatures are aligned, then the refrigerant charge is optimized, and if they are not aligned, the system is undercharged or overcharged.

Abstract: An air-conditioning system capable of reducing traffic of signals and effectively performing control and management operations without causing heavy traffic is obtained. In an air-conditioning system including one or more indoor units 200, one or more outdoor units 100, and a centralized control apparatus 300 and performing signal communication, a transmission relay 400 is provided between a first transmission line 500 to which the one or more outdoor units 100 and the centralized control apparatus 300 are connected and a second transmission line 510 to which one or more indoor units 200 constituting a group are connected, the transmission relay 400 relays a signal between the first transmission line 500 and the connected second transmission line 510.

Abstract: Disclosed is a device for the transport of temperature sensitive products including an insulated container, an insulated lid, a fastener to secure the lid to the container, an active heat exchanger, a thermal circuit to circulate heat exchange, a temperature sensor read by a temperature regulating circuit that maintains a temperature range, a power source, and a support frame that arranges the elements of the device with the overall center of mass at a location adapted for transport and storage of the device. Disclosed is also a method of transport for temperature sensitive products including securing the temperature sensitive product within an insulated container with a lid, removing heat from the container to maintain a temperature range, strapping the device onto the user's back and adjusting to the shape of the user, freeing both hands during transport of the device, and minimizing hindrances to user mobility caused by the device.

Abstract: An apparatus for optimizing an efficiency of a refrigeration system, comprising means for measuring a refrigeration efficiency of an operating refrigeration system; means for altering a process variable of the refrigeration system during efficiency measurement; and a processor for calculating a process variable level which achieves an optimum efficiency. The process variables may include refrigerant charge and refrigerant oil concentration in evaporator.

Abstract: An operation information processing section (11) in a central remote controller (5) processes operation information from operation setting buttons (8a, 8b, 8c), each of which is independent in function, transmits the operation information through a transmission line (6), and generates screen information based on the operation information collected through the transmission line (6), and display the screen information on a display unit (9). A management information processing section (12a) generates screen information based on operation information of the air conditioners (1, 2) collected through the transmission line (6) and transmits the screen information to the remote monitor terminal (15) through a transmission line (13), and relays control information transmitted from the remote monitor terminal (15) through the transmission line (13), and transmits the control information to the air conditioners (1, 2) through the transmission line (6).