Abstract: A cooling apparatus comprises a main refrigerator having a refrigerant-filled chamber, a sub-refrigerator connected parallel to the main refrigerator and having a refrigerant-filled chamber, switch control means for controlling the switching operation between the supply of a refrigerant used in the main refrigerator to the sub-refrigerator, and the stop of the supply of the refrigerant, on the basis of predetermined conditions.

Abstract: A plurality of remote control groups (GR) each have a plurality of indoor units (20, 20, . . . ) designated as a single master unit (2a) and as slave units (2b) cooperating with the master unit (2a). A central monitor board (30) is provided for communicating control signals with each of the indoor units (20, 20, . . . ). A memory of the central monitor board (30) has a type area (M2) for storing type data representing that each indoor unit is a master unit (2a) or a slave unit (2b). The central monitor board (30) transmits a start signal to the indoor unit (20) as a master unit (2a) in accordance with type data of the type area (M2). In addition, the central monitor board (30) determines that the indoor units (20, 20, . . . ) having begun to operate in response to the start signal belong to one group (GR) and enters the determination result in a group area (M3) of the memory.

Abstract: A control apparatus for a multi-air-conditioner having an external unit and a plurality of internal units includes a DC electric power supply. An external transmitting/receiving circuit is provided with the external unit and is connected with the DC electric power supply, and a plurality of internal transmitting/receiving circuits are provided with the plurality of internal units and are connected serially with the external transmitting/receiving circuit via a signal line. A DC voltage is supplied for transmitting data from the external unit to the internal unit, which reduces a leakage distance of the circuit. A timing for transmitting data can be set freely, a transmitting speed of data can be improved using a high-speed photo-coupler, and thus an operation speed of the internal unit can be improved in the multi-air-conditioner having the plurality of internal units.

Abstract: In a multiple type air conditioner system which includes a plurality of outdoor units and a plurality of indoor units, the plurality of outdoor units are connected with the plurality of indoor units through a communication line, address setting is attained by generating a random address from each of all the indoor units under a command of one of the outdoor units and generating a dummy address from each outdoor unit on the basis of the random address, by obtaining a correlative relationship between the outdoor and indoor units on the basis of a variation of a physical quantity of the outdoor unit connected to the indoor unit actually operated based on the dummy address, and by updating the addresses of all the outdoor and indoor units on the basis of the correlative relationships between all the outdoor and indoor units obtained through the step.

Abstract: In a positive displacement compressor having a plurality of banks, operation can be multi-staged or single staged. Single stage operation can be of a single bank or plural banks in parallel. Switchover between modes of operation is under the control of a microprocessor responsive to sensed inputs. During pulldown under ambient or condenser entering air temperatures of 100.degree. F., or more, suction modulation is used to limit the suction pressure thereby permitting a switchover to two-stage operation and the use of an economizer.

Abstract: This invention presents an air condition utility system for providing air condition to sets of buildings, with each building having a number of amended air conditioning systems, by repeatedly circulating a refrigerant in a closed loop. Each station is connected to an assigned set of buildings of a district by high-pressure lines and low-pressure lines. High-pressure lines are used to transfer the refrigerant, in a liquid stage, from a station to each building that is served by the station. Upon providing air condition to a building, the refrigerant loses pressure and returns in a partial-gas partial-liquid stage through downwardly-sloped low-pressure lines from the building to the station. In the station, the refrigerant is pressurized by passing through a number of compressor units and again leaves the station in a liquid form through the high-pressure lines.

Abstract: A method of cooling an object with a thermoelectric battery cascade which is based on carrying heat from the object and further from stage to stage with an adjustable regulated direct current applied to the terminals of the battery until a steady-state operation mode is obtained corresponding to the required temperature of the object being cooled. In accordance with the invention transfer of heat removed from the object is effected successively in time in portions from stage to stage with intermediate heat storage on heat accumulators. In order to effect this, the operation of each stage is carried out in active heat removal and thermal switch modes, wherein the duration of the time intervals and values of currents flowing through the stages of the thermobattery for those modes is adjusted in the process of bringing it to the steady-state mode of operation with required values of temperatures of the object being cooled and heat accumulators and with minimum value of electric power consumption.

Abstract: A multi-type air conditioner address setting method and address setting device for automatically setting an address with a simple structure. A dummy address sent from an exterior device is stored in an interior device. The interior device determines whether the interior device itself is operating in a designated operation mode. When the interior device is operating in the designated operation mode, the dummy address is set as an actual address. When an address request signal is sent from the exterior device, the set address is sent back thereto.

Abstract: An energy-efficient refrigeration system includes a dual cylinder compressor and a compressor controller coupled to the compressor to control compressor capacity by selection of a predetermined refrigerant flow path through the compressor. The dual cylinder compressor includes first and second cylinders with respective first and second pistons that are horizontally opposed and coupled together by a fixed and non-pivoting connecting rod. The void volume of one cylinder is typically greater than the void volume of the other cylinder, and the compressor typically is a scotch-yoke drive apparatus or, alternatively, a linear voice coil drive apparatus.

Abstract: An ON-OFF controller (5B) connected to a plurality of indoor units (3, 3, . . . ) specifies a range of address settings of each of the indoor units (3, 3, . . . ) managed by the ON-OFF controller (5B), and outputs a signal showing the range of address settings to the respective indoor units (3, 3, . . . ) based on the range of address settings. When receiving the signal showing the range of address settings from the ON-OFF controller (5B), each of the indoor units (3, 3, . . . ) outputs to a remote control (4) a signal allowing an address setting, and stores an address for itself inputted from the remote control (4). The remote control (4) indicates the range of address settings when receiving the signal allowing an address setting from the indoor unit (3, 3, . . . ), and has an input button (4c) by which an address of the indoor unit (3, 3, . . . ) is inputted.

Abstract: A compressor control system for a commercial refrigeration system includes a variable speed compressor and multiple fixed speed compressors. The control system calculates a variable which fluctuates according to the desired capacity of the system and is calculated as a function of the difference between a variable indicative of the refrigeration load on the system, such as compressor suction pressure, and a target value. A "PID" proportional-integral-differential (PID) controller is used in which terms have been added which fluctuate as a function of the square of the difference between the sensed variable and the target value and as a function of the second derivative of the control variable with respect to time. Fixed speed compressors are turned on or off and the speed of the variable speed compressor is adjusted to bring the actual refrigeration capacity of the system in line with the system refrigeration requirements.

Abstract: In a refrigeration system having low and high stage compressors and a subcooler or economizer, economizer gas is selectively supplied to the compressor motors for cooling and to the suction of the high stage to increase capacity. By selectively controlling the delivery of the economizer gas, efficiency of the refrigeration system is increased.

Abstract: Two compressors are connected in tandem for an air conditioning system. A control board that includes a microcontroller controls the operation of the system in response to the energization of first and second stage terminals of a thermostat. The system includes anti-short cycling and eliminating operation of crankcase heaters during a time period following the shutting off of the compressors.

Abstract: An interface circuit for producing a single DC control voltage in response to any one of a plurality of different AC control voltages. The interface circuit includes a plurality of AC inputs for receiving different respective AC control voltages and a DC output. A comparator controls the voltage at the DC output in accordance with a reference voltage and a DC control voltage. An AC to DC converter includes a scaling network which generates the same DC control voltage without reference to which one of the AC inputs is receiving its respective AC control voltage.

Abstract: A broad range cooling system is provided which can operate to cool and store a product load to a predetermined temperature in the range of -25.degree. F. to +75.degree. F. over an ambient temperature range of -60.degree. F. to 150.degree. F. The system includes two compressor systems which are configurable to operate independently as single stage compressor cooling systems each having a unique cooling range, or together as a single stage compressor system or a compound system, depending upon the desired temperature requirements of the load and the existing ambient. In the event of a failure of one or the other compressor, the system is configured to continue operation with the other compressor as a single stage compressor system until a repair can be affected.

Abstract: Apparatus for providing integrated control of a space cooling system is disclosed. The apparatus receives inputs from a plurality of temperature sensors, including a temperature sensor for measuring evaporator superheat, space temperature and compressor discharge temperature. The control apparatus incrementally adjusts the position of the cooling system expansion valve to regulate evaporator superheat and compressor discharge temperature and cycles the outdoor condenser fan on and off to raise condenser pressure in response to a low condenser pressure condition. In one embodiment, the cooling system includes a plurality of evaporators and a corresponding plurality of controllers electrically interconnected in a series loop for controlling the expansion valves and defrost heaters associated with the respective evaporators.

Abstract: Liquid lines (5LA, 5LB) and gas lines (5GA, 5GB) are connected to a main liquid line (4L) and a main gas line (4G) respectively so that a master outdoor unit (2A) and a slave outdoor unit (2B) are arranged in parallel with each other. On the gas line (5GB) extending from the slave outdoor unit (2B), a gas stop valve (V2) which is fully closed when the slave outdoor unit (2B) is deactivated during heating operation is disposed. On the liquid line (5LB) extending from the slave outdoor unit (2B), a liquid stop valve (V1) which is fully closed when the slave outdoor unit (2B) is deactivated during cooling operation and heating operation is disposed. Thus, compression of a liquid refrigerant and lack of a circulation amount of refrigerant are prevented.

Abstract: An automotive vehicle has an air compressor; a compressed tank for storing air compressed by the compressor; and a system for selectively releasing compressed air from the tank into the vehicle's passenger compartment to cool it. Preferably the vehicle includes a ventilation system and the compressed air is released into the ventilation system's air passageways. If the vehicle include a traditional air conditioning system using the evaporation of refrigerant to cool air, the release of compressed air can be used to provide cooling until a sensor indicates the traditional air conditioning system is capable of providing sufficient cooling. Preferably a radiator is located in the line between the air compressor and the compressed air tank to transfer heat away from the compressed air before it is stored in the tank. It is also preferred that controls in the vehicle's passenger compartment enable a passenger to control the release of the compressed air.

Abstract: Liquid lines (5LA, 5LB) and gas lines (5GA, 5GB) are connected to a main liquid line (4L) and a main gas line (4G) respectively so that a master outdoor unit (2A) and a slave outdoor unit (2B) are arranged in parallel with each other. On the gas line (5GB) extending from the slave outdoor unit (2B), a gas stop valve (V2) which is fully closed when the slave outdoor unit (2B) is deactivated during heating operation is disposed. On the liquid line (5LB) extending from the slave outdoor unit (2B), a liquid stop valve (V1) which is fully closed when the slave outdoor unit (2B) is deactivated during cooling operation and heating operation is disposed. Thus, compression of a liquid refrigerant and lack of a circulation amount of refrigerant are prevented.

Abstract: A setting button (53) for setting an option for changing a driving mode is provided in any one of indoor control units (3) belonging to each of refrigerant control systems (12, 13). An outdoor control unit (2) sets to each indoor control unit (3) a system number of the refrigerant control system (12, 13) to which each indoor control unit (3) belongs. The indoor control unit (3) outputs an option holding signal and a system signal of the system number. A integral controller (4) is provided with a system indicating button (6a) for indicating the option and the refrigerant control system (12, 13). Further, the integral controller (4) is provided with an option indicating lamp (HSM) for indicating the option and a system indicating lamp (HLM) for indicating the refrigerant control system (12, 13).

Abstract: In a multiple type air conditioner system which includes a plurality of outdoor units and a plurality of indoor units, the plurality of outdoor units are connected with the plurality of indoor units through a communication line, address setting is attained by generating a random address from each of all the indoor units under a command of one of the outdoor units and generating a dummy address from each outdoor unit on the basis of the random address, by obtaining a correlative relationship between the outdoor and indoor units on the basis of a variation of a physical quantity of the outdoor unit connected to the indoor unit actually operated based on the dummy address, and by updating the addresses of all the outdoor and indoor units on the basis of the correlative relationships between all the outdoor and indoor units obtained through the step.

Abstract: In a multiroom air conditioner and a method of driving a multiroom air conditioner containing plural outdoor side units each containing a compressor, an outdoor fan, an outdoor heat exchanger and a refrigerant path change-over valve, plural indoor side units each containing an indoor heat exchanger, and an inter-unit pipe comprising a high-pressure gas pipe, a low-pressure gas pipe and a liquid pipe through which the plural outdoor side units are connected to the indoor side units to thereby form a refrigerant cycle, and in which each individual indoor side unit independently and selectively performs a room cooling operation or a room heating operation for an individual room, when a stop signal is output to some outdoor side unit in accordance with an indoor load during a room cooling or heating operation, the refrigerant path change-over valve of the outdoor unit is switched and the outdoor fan thereof is driven so that the driving of the compressor of the outdoor side unit is stopped, but refrigerant is all

Abstract: A method of controlling a plurality of commonly piped compressors for a refrigeration system having a plurality of refrigeration cases including the steps of sensing a suction pressure of the refrigeration system, determining whether the sensed suction pressure is within a predetermined pressure range, and turning compressors ON or OFF in stages until the suction pressure is within the predetermined pressure range. The method also includes the steps of sensing a case temperature for each of the refrigeration cases if the sensed suction pressure is within the predetermined pressure range and determining whether the sensed case temperature is within a predetermined temperature range.

Abstract: A broad range cooling system is provided which can operate over a temperature range of -25.degree. F. to 75.degree. F. under any expected ambient temperatures. The system includes two compressor systems which are configurable to operate independently and as a cascade system to provide multiple cooling temperatures for multiple loads each having a particular temperature requirement. There are multiple evaporator systems for cooling air which is used to cool the product; one evaporator system for each desired temperature. Each evaporator system is provided a thermal expansion valve, a corresponding thermostatic bulb and a thermostat to control the temperature in a corresponding chamber. The container is partitioned into chambers, each chamber having an evaporator system so that each evaporator system provides positive temperature control within its chamber.

Abstract: A control system for controlling a plurality of compressors by means of fuzzy logic. Control is provided by selecting a combination of available compressors, which may include one or more fixed speed compressors and a variable speed compressor. The controller output signals are responsive to inputs monitoring either the pressures in the system's refrigerant suctions lines, the temperatures of the refrigerated spaces, or where a plurality of evaporators are connected to a set of compressors, the temperature of the coldest refrigerated case, or a combination of the desired suction pressure and temperature of the refrigerated space. The output capacity of the system is chosen based on the degree of membership of each input variable as compared to the total for all inputs.

Abstract: An air conditioning control system ensuring the desired full utility so that the operation of a plurality of air conditioners installed in a building can be controlled and monitored at a plurality of spots in the building. The air conditioning control system includes a building's central monitor board controlling and monitoring the operation of the individual air conditioners, and a centralized control unit relaying air conditioner control information outputted from the central monitor board and information indicating the operation status of the individual air conditioners, each of the central monitor board and the centralized control unit including an input part inputting the control information to the individual air conditioners and a display part displaying the operation status information regarding the individual air conditioners.

Abstract: A broad range cooling system is provided which can operate over a temperature range of -25.degree. F. to 75.degree. F. under any expected ambient temperatures. The system includes two compressor systems which are configurable to operate independently, or as a cascade system, depending upon the desired temperature requirements of the load in relation to the ambient. There are two separate evaporator systems for cooling air which is used to cool the product; one evaporator system for each compressor. In single compressor mode, the selected compressor is used to cool its respective evaporator system and each compressor system is automatically configured to utilize the primary condenser to convert hot gas to a liquid. In cascade cooling mode, the lower compressor system is automatically reconfigured to utilize an evaporator side of a heat exchanger to convert hot gas to a liquid and to utilize the primary condenser to evaporate the liquid to a cold gas while absorbing heat.

Abstract: A broad range cooling system is provided which can operate to cool a product load to a predetermined temperature in the range of -25.degree. F. to +75.degree. F. over an ambient temperature range of -60.degree. F. to 150.degree. F. The system includes two compressor systems which are configurable to operate independently as single compressor cooling systems each having a unique cooling range, or together as a cascade system, depending upon the desired temperature requirements of the load and the ambient. In the event of a failure of one or the other compressor, the system is configured to continue operation with the other compressor as a single compressor system until a repair can be affected.

Abstract: An air condition control unit is provided with an EEPROM previously memorizing respectively different specific numbers of indoor control units and power supply means. Further provided thereto are power supply judging means for judging whether a remote controller receives the power from another indoor control unit by monitoring power source lines, and power not-supply determining means for determining the unit of its own to be a unit which does not supply the power to the remote controller when the power supply judging means judges the remote controller receives the power.

Abstract: A heat storage type air conditioner which is free from a difficulty that, when a general cooling and heating circuit and a cold radiating and heat radiating circuit are operated separately or simultaneously, the quantities of refrigerant in those circuits become smaller or larger than required, so that its compressor is damaged or the cooling or heating capacity is lowered. When, in a heat storage type air conditioner, first and second bypass circuits 22 and 23 are closed, a general cooling and heating circuit 18 driven by a compressor 1 and a cold radiating and heat radiating circuit 21 driven by a refrigerant gas pump 13 are made independent of each other, so that a cooling operation or a heating operation is carried out with the aid of a first use-side heat exchanger 4a and a second use-side heat exchanger 4b. Therefore, in the air conditioner, the refrigerant or refrigerating machine oil will never concentrate in any one of the two circuits.

Abstract: A distributively arranged air conditioner group apparatus includes plural groups of air conditioners distributively arranged at remote locations wherein each group consists of a plurality of units on the heat source side and a plurality of units on the utilization side located remote from each other and a single signal line is used for a plurality of communication signal lines each usable for the purpose of controlling. To prevent a controlling operation from being erroneously performed at the time of an occurrence of signal interference, specific communication addresses are set to the respective units for the purpose of controlling communication among these units. The communication addresses are set for each group immediately after the apparatus is installed or at the time of starting of an operation of the apparatus by utilizing a plurality of heat source pipings extending between the units on the heat source side and the units on the utilization side for each group.

Abstract: A cooling system which is modular and capable of maintaining a variety of pre-selected temperatures for a plurality of liquids being dispensed and/or a plurality of spaces being air conditioned. A single refrigerator unit has a chilled glycol distribution line connected thereto and through which the chilled glycol is pumped. One or more cooler modules are tapped into the glycol distribution line at points wherever desired. The modules contain a low boiling refrigerant, a fluid tube carrying a relatively warm fluid (liquid or air), a cooling tube connected to the distribution line run and a flow control valve responsive to pressure changes in the module for permitting flow of chilled glycol thereinto and being adjustable to achieve the desired temperature of the fluid within the fluid tube.

Abstract: An air conditioner in which, when a first compressor is being operated and a second compressor is being stopped, liquid refrigerant does not flow into the second compressor even in a state of wet vapor suction, a decrease in lubricating oil in the second compressor or a decline in its concentration are not experienced, and breakage of the second compressor does not occur owing to faulty lubrication when the second compressor is started. In addition, to obtain an air conditioner which does not lapse into a wasteful shortage of cooling and heating capabilities when the air conditioner is not in the state of wet vapor suction, by reliably detecting the presence or absence of the state of wet vapor suction. In the air conditioner, the first compressor and the second compressor are connected together by an equalizing pipe. A bypass passage which connects together a discharge pipe and a suction pipe of the second compressor is provided.

Abstract: In a multiroom air-conditioning apparatus, refrigerant flow between plural outdoor side units is controlled so that abnormality (lack or excess) of refrigerant amount in an outdoor side unit in operation is redressed. For example, when surplus refrigerant exists in an outdoor side unit, the refrigerant flow is so controlled that the surplus refrigerant is pushed out (flow out) into an outdoor side unit in non-operation. In addition, the output of the air-conditioning apparatus is smoothly variable (controllable) in accordance with an air-conditioning load over the whole air-conditioning load range from the minimum (zero) load to the maximum load.

Abstract: When cooling power corresponding to an amount of heat generated by an electronic apparatus can be generated by either n or n+1 cooling units, n+1 cooling units are operated such that each of the cooling units keeps a sufficient margin in reserve. In this manner, even if an abnormality occurs in one of the cooling units, the operation can be continued by the n cooling units. Further, since an operation frequency of a compressor in the cooling unit can be decreased to rotate a motor in the compressor at a lower rotational speed, a speed at which a bearing is worn is slowed, whereby the useful life of the bearing can be prolonged.

Abstract: A multiple type air conditioning apparatus includes a refrigerant supply unit having a variable capacity compressor, at least two internal air conditioning units each having an internal heat-exchanger and a fan device, the internal heat-exchangers of the at least two air conditioning units being connected in parallel to one another, a first variable expansion valve for variably throttling refrigerant, fed from the compressor, flowing through one of the internal heat-exchangers, a second variable expansion valve for variably throttling refrigerant, fed from the compressor, flowing through the other internal heat-exchanger and a variable flow rate control unit arranged at one side of the internal heat-exchangers from which refrigerant flows into each internal heat-exchanger in a heating operation, for regulating a distribution of refrigerant flowing into each internal heat-exchanger.

Abstract: Supplementary cooling for a mechanical refrigeration plant using ammonia as a refrigerant is provided by placing a tube in the vapor space of a buffer vessel and introducing liquid nitrogen into the tube. Although ammonia solidifies at -78.degree. C. and liquid nitrogen enters the tube at -196.degree. C. no ammonia solidifies on the tube even after extended operation. The present invention also provides a method of refrigeration which comprises introducing liquid nitrogen into the heat exchanger of a refrigeration apparatus in accordance with the invention and condensing refrigerant therewith. Preferably, the refrigerant is selected from the group consisting of ammonia and fluorocarbon R22.

Abstract: System and process are disclosed for the hierarchial control of a plurality of discrete chiller units each having individual dedicated controls. The system and process imposes limits on the amount of compression that can be demanded by the individual dedicated controls. These limits are selectively changed in response to whether a level of chilling has been collectively achieved. The selective changing of these limits is premised on examinations of each individual chiller unit including the recent history of any changes in compression by the unit.

Abstract: A heat storage type air conditioning system capable of performing refrigerant receiving and discharging control and oil quantity control, which, in operating the general cooling circuit and the cold radiating circuit simultaneously or separately, is free from difficulties that the compressor is damaged or the cooling capacity is lowered when the quantities of refrigerant in those circuits are excessively increased or decreased, and is able to continue the operations with the quantity of refrigerant and the quantity of ice machine oil adjusted to suitable values. In the heat storage type air conditioning system, evaporators are provided in a general cooling circuit driven by a compressor and in a cold radiating circuit driven by a refrigerant gas pump, respectively, so that those circuits operate independently of each other. Furthermore, bypass circuits are provided to allow refrigerant to flow between liquid pipes and between gas pipes in those circuits.

Abstract: A twinning controller or control circuit for use in an HVAC system is coupled between a system thermostat and at least two HVAC units coupled to a common duct. The HVAC units are heating, cooling or heating and cooling appliances such as heating furnaces, air conditioners, fans, other forced air systems, or other devices for heating and/or cooling an environment. The twinning controller is capable of operating in a single-stage mode (single mode) or a double-stage mode (dual mode). When operating in the double-stage mode, the twinning controller alternately operates the first HVAC unit and the second HVAC unit in order to extend the operating life of the HVAC units. The twinning controller includes a microcomputer which receives inputs from the system thermostat and provides outputs to the first and second HVAC units in order to efficiently control the temperature in an environment such as a living space.

Abstract: The operation of indoor devices in a multiple unit air conditioning system are monitored by an operation sensing portion. After all the indoor devices are turned off, the compressor continues to operate for a length of time determined by the time constant delay portion and then is turned off. Once the solenoid valves 4 feeding refrigerant to the indoor heat exchangers 3 are closed, the continued operation of compressor 6 causes an over-pressure relief valve 8 to open. This equalizes the pressure difference between the suction line and the high pressure discharge line of the compressor and thereby allows for faster restarts than a conventional bypass line 9.

Abstract: System and process are disclosed for the monitoring of certain parameters for the purpose of exercising supervisory control over a number of discrete chiller units each having their individual dedicated controls. The supervisory control is accomplished by imposing limits on the amount of compression that can be demanded by the individual dedicated control units. These limits are selectively changed when certain parameters pertaining to the collective chilling capacity of all of the active chiller units exceed or fall below acceptable levels.

Abstract: A variable-capability compressor and an outdoor heat exchanger installed in an outdoor unit and indoor heat exchangers installed in each of a plurality of indoor units are connected by pipes so as to form a refrigerating cycle. The air-conditioning load on each of the indoor units is detected. The capability of the variable-capability compressor is controlled according to the sum of the air-conditioning loads on the respective indoor units. At the time of a heating operation, the refrigerant heat loss in each of pipes respectively connected to the indoor heat exchangers is detected. When the refrigerant heat loss in at least one of the pipes is a given value or more, the capability of the variable-capability compressor is enhanced to compensate for the refrigerant heat loss.

Abstract: A method and apparatus for controlling the capacity of a multi-stage cooling system is disclosed. The system of the invention utilizes a plurality of commonly piped compressors being a variable speed compressor, means for establishing a single predetermined cooling state "cut-in" pressure and a single predetermined cooling state "cut-out" pressure, a plurality of condenser fans and a microprocessor based control means for controlling the operation of the system.

Abstract: Multi-purpose indoor units and multi-purpose outdoor units are parallel-connected with each other by refrigerant pipes, and an operating capacity is obtained on the basis of the sum of the demanded capacities of the indoor units and on the basis of the compressor type and maximum capacity of the outdoor units using a control apparatus.

Abstract: An outdoor unit has a compressor and an outdoor heat exchanger. Each of a plurality of indoor units has an indoor heat exchanger. The outdoor unit is connected in parallel with the plurality of indoor units to form a multi-type air conditioner system having a plurality of refrigeration cycles. A plurality of gaseous flow adjustment valves are provided to the gaseous sides of the indoor units, respectively. A plurality of liquid expansion valves are provided to the liquid sides of the indoor unit, respectively. A refrigerant super-heat degree detector detects a refrigerant super-heat degree of the outdoor heat exchanger or the indoor heat exchangers.

Abstract: An evaporative heat pump apparatus which utilizes a computer and a pulse width modulation control system, solenoid valves and multiple evaporators to alter heat input capabilities by increments in order to maintain a constant rate of heat output regardless of changes in ambient conditions such as temperature, humidity, wind velocity and other factors is described.

Abstract: An air-conditioning apparatus comprises at least one variable-capability compressor which is contained in a casing together with a lubricating oil, and at least one fixed-capability compressor which is also contained in a casing together with a lubricating oil. The capability of the variable-capability compressor and the number of fixed-capability compressors to be driven, are controlled in accordance with the sum of the air-conditioning loads of a plurality of indoor units. The casings are connected together by means of an oil-balancing pipe. The air-conditioning apparatus further comprises a plurality of oil-balancing devices. These oil-balancing devices are driven on the basis of different control patterns and distribute the lubricating oil between the casings by way of the oil-balancing pipe. The oil-balancing devices are selectively driven in accordance with both the control of the capability of the variable-capability compressor and the control of the number of fixed capability compressors to be driven.

Abstract: A method of staging and modulating compressors in a multi-circuited refrigeration system including a plurality of condensing heat exchange circuits where each condensing heat exchange circuit includes a plurality of compressors. The method comprises the steps of: accumulating a first operative condition for each compressor; accumulating a second operative condition for each compressor; determining the status of each compressor in each circuit and designating therefrom a first list of circuits having compressors available to be turned on and a second list of circuits having compressors available to be turned off.

Abstract: A control for a multiple chiller refrigeration system whereby a chiller can be stopped at a predetermined load in order that the remaining building load can be picked up by the remaining running chillers without exceeding set load capacities of the running chillers.