Abstract: In an air conditioner for a hybrid vehicle, an air conditioning unit performs air-conditioning operation by electrical power supplied from a battery. When a residual charging degree of the battery becomes equal to or lower than a target degree, an electrical motor generator is driven by a vehicle engine so that the battery is charged through the electrical motor generator. Further, when a rotation speed of the engine is lower than a predetermined speed or when a power generation efficiency due to the engine is lower than a predetermined efficiency, air-conditioning capacity of the air conditioning unit is set lower, so that a consumption power of the air conditioner is restricted. Accordingly, the frequency for starting the engine only for charging the battery can be reduced.

Abstract: Methods and apparatus for monitoring power outages in a household appliance such as a refrigerator are disclosed. According to the method, a household appliance determines a prior occurrence of a power outage to the appliance. The household appliance then computes a duration of the power outage. Further, the household appliance alerts a user of the duration of the power outage.

Abstract: Apparatus and method of monitoring operation of a temperature control apparatus. The apparatus includes a controller, a refrigeration circuit extending between a compressor, a condenser, and an evaporator, and a drive unit operably connected to the compressor. The drive unit has a fuel supply, a plurality of cylinders, a fuel line extending between the fuel supply and the plurality of cylinders, and a sensor positioned between the fuel supply and the cylinders to record fuel flow. The method includes directing air across the evaporator, recording a fuel flow rate with the sensor, calculating an actual output power of the drive unit using the fuel flow rate, calculating an expected output power of the drive unit, and comparing the actual output power of the drive unit and the expected output power of the drive unit to predict malfunctions of the apparatus.

Abstract: A hybrid compressor system in a vehicle air conditioner includes a variable displacement hybrid compressor, a detector for detecting information for air conditioning, a thermal load calculator and a controller. The compressor is selectively driven by an engine and an electric motor. The calculator calculates a thermal load based on the detected information. The controller compares the thermal load with a predetermined value. The controller changes displacement of the compressor to a first predetermined displacement value and selects the engine as a drive source of the compressor when the thermal load is larger than the predetermined value. The controller changes the displacement of the compressor to a second predetermined displacement value that is smaller than the first predetermined displacement value and selects the electric motor as the drive source of the compressor when the thermal load is equal to, or smaller than the predetermined value.

Abstract: A process for estimating the capacity and the coefficient of performance by taking common measurements and using compressor manufacturer's performance data is presented. A process for determining a capacity index and an efficiency index for a vapor compression cycle relative to desired operating conditions.

Abstract: A hybrid compressor system has a hybrid compressor for compressing refrigerant. The compressor is selectively driven by one of a first drive source and a second drive source. The hybrid compressor system also includes a first one-way clutch, a driver for driving the second drive source, a sensor for detecting a rotational state of the first drive source and a controller. The first one-way clutch is arranged on a first power transmission path between the compressor and the first drive source for permitting power transmission from the first drive source to the compressor. The controller is electrically connected to the driver and the sensor. When a drive source of the compressor is switched from the second drive source to the first drive source, the controller orders the driver to stop the second drive source after the rotation of the first drive source is detected.

Abstract: There is provided an automotive air conditioning system, which is free from troubles in traveling itself caused by power consumption in air conditioning means in an automobile having storage means, power generation means for charging the storage means, and air conditioning means having an electric compressor driven by feeding from the storage means.

Abstract: An electric compression device has a motor section and a compressor section contained in a housing, an inverter attached to the outer surface of the housing, and a temperature measurement device for measuring a temperature of the inverter. In a stopped state of a refrigeration cycle system, a control unit drives the motor section when the temperature of the inverter, measured by the temperature measurement device, exceeds a predetermined temperature.

Abstract: Disclosed are an air conditioning system with two compressors and a method for operating the same, so as to variably change a compression capacity of a refrigerant according to the variation of cooling load. Herein, when a full operation order is inputted to the two compressors in order to satisfy increased cooling load, the first compressor is first operated, and then the second compressor having a compression capacity of a refrigerant smaller than that of the first compressor is additionally operated, so that a current peak value for operating the compressors does not exceed an allowable current range of a circuit breaker installed in a home or building, thereby safely controlling the air conditioning system and simultaneously allowing the current to be provided to other electric appliances, thus improving users' convenience.

Abstract: In a motor vehicle with a combustion engine, an electronic engine-management device, and an air-conditioning system with an air-conditioning control device, the air-conditioning compressor has reciprocating pistons whose displacement stroke is adjustable through one or more control valves. The electronic engine-management device has direct access to and priority control over the adjustment of the piston stroke, so that the electronic engine management device takes precedence over the air-conditioning control device in controlling the adjustment of the piston stroke.

Abstract: The object of the present invention is to provide a method of controlling a refrigeration cycle such that maximum refrigerating capacity can be educed when the refrigeration cycle is started, the driving torque of a variable displacement compressor can be reduced when an automotive vehicle performs standing start or acceleration, and the refrigeration cycle can be operated with the maximum efficiency in a steady operating condition.

Abstract: A control method for a motor vehicle HVAC system categorizes potentially conflicting override commands for at least one control parameter in order to assign a priority of control. Override commands are categorized as being related to occupant safety, vehicle safety or occupant comfort. Highest priority is assigned to override commands categorized as being related to occupant safety, second-highest priority is assigned to override commands categorized as being related to vehicle safety, and third-highest priority is assigned to override commands categorized as being related to occupant comfort. An HVAC controller carrying out the control method then regulates the control parameter in accordance with the override command that has been assigned the highest priority.

Abstract: A refrigerant compressor driven by an electric motor, whose supply frequency is selectively variable between a discrete number of values (f1, f2, fT) as a function of an input signal, uses control means integrated in the compressor to monitor two or more quantities that are variable with time in a mutually independent manner, of which at least one is representative of the actual operating conditions of the appliance. The control means also generates the input signal with a value that corresponds to a pre-established combination of the monitored quantities.

Abstract: In an air conditioner including a control unit receiving a power from a switching power supply, the switching power supply is connected to a DC power source without passing through a switch device or power application device. The output of the switching power supply is connected to a capacitor via a diode. The control unit is able to operate even when the capacitor to be charged via the power application device is not charged. Accordingly, the motor-driven compressor may start to operate quickly.

Abstract: An air-conditioning system for a vehicle, including a refrigerant circuit and an engine, has a battery, a compressor, an electric motor and a load torque control mechanism. The battery supplies electric power. The compressor is operative to compress refrigerant gas for the air-conditioning system. The electric motor is electrically connected to the battery. The motor is driven due to the electric power, and is operatively coupled to drive the compressor when the motor is energized. The load torque control mechanism responsive to the operating condition of the engine to control the load torque of the compressor below a predetermined value during times when the motor is driving the compressor.

Abstract: A system provides the operator of a refrigeration package, such as a water-chilling package, with both short term and long term economic and quantitative analyses of the operating chiller, comparing the existing performance to the hypothetical design rated performance of other chillers, using actual operating conditions and parameters. The system performs such analyses using either historical evaporator tonnage and actual power usage data, or works in real time to provide a “snapshot” economic forecast, based on the immediate conditions. During real time monitoring of various performance data, the system can also identify unsatisfactory performance conditions, i.e. faults, and provide the operator with onsite information as to the possible causes of, and potential solutions to, the unsatisfactory condition.

Abstract: A compressor device for a refrigerant cycle includes a compressor and a control unit. The compressor is provided with a displacement changing mechanism for changing its displacement. The control unit changes a current value supplied to the displacement changing mechanism, thereby relatively changing the displacement of the compressor. In the compressor device, when a rotational speed of a vehicle engine is lower than a predetermined rotational speed, the control unit controls an upper limit of the current value between a first predetermined value and a maximum value. Accordingly, a displacement specification of the compressor device can be normalized for vehicle engines having different power outputs, while engine stall can be prevented.

Abstract: Disclosed are an apparatus for preventing an overload of an air conditioner and a method thereof. The apparatus includes current feedback units for feeding back the currents supplied to the compressors to the controller where at least one of a plurality of compressors, operated in response to currents generated from a controller for controlling an operation of the air conditioner, is in an overload state; and a comparator for sensing current differences between the currents inputted into the compressors and the currents fed back from the current feedback units. After sensing the current differences between the currents inputted into the compressors and the currents fed back from the current feedback units, the comparator determines that at least one of the compressors is in the overload state if a current difference does not exist.

Abstract: A power supply control apparatus is provided for a vehicle that includes air-conditioning electric devices and other electric devices. In the power supply control operation, current target power that is necessary for the specific electric device is calculated based on precedent target power calculated last time; allowed power that is allowed to be supplied to a specific electric device is calculated based on total power demand of the vehicle; power to be supplied to the specific device to the allowed power if the current target power is larger than the allowed power; and the precedent target power is replaced with the allowed power if actual power supplied to the specific electric device is limited to the allowed power.

Abstract: If a motor breaks down, an appropriate measure is taken according to the type pf the breakdown. If the breakdown is judged to be due to abnormal energization of the motor by electrical abnormality judgment means, a drive source for a hybrid compressor is secured while preventing an engine for traveling from stopping by compressor operation continuation means. If it is judged that the driven state of the motor is abnormal, the hybrid compressor is disconnected from the engine to protect the engine from mechanical abnormality of the hybrid compressor.

Abstract: The invention relates to a switch cabinet or cover with an air-conditioning unit, which comprises a cooling circuit system with an evaporator and a condenser. The evaporator has an integral air circuit, connected spatially with the interior of the switch cabinet and through which the air in the interior of the switch cabinet may be forced, by means of a blower. The condenser is in contact with the remaining components of the cooling circuit, by means of refrigerant lines. According to the invention, in order to reduce emissions from the air-conditioner, due to environmental damage considerations, the evaporator, together with the dedicated blower, is integrated in an evaporator unit, attached to the switch cabinet. The condenser, together with a dedicated blower, is integrated in a condenser unit, whereby the condenser unit is spatially separate from the evaporator unit and from the switch cabinet.

Abstract: A refrigeration cycle apparatus having a linear compressor is provided with a volume circulation rate instruction unit for obtaining a volume circulation rate Vco of a refrigerant in accordance with refrigerating capacity required of the refrigeration cycle apparatus, on the basis of an ambient temperature of an indoor heat exchanger (evaporator), a target temperature set on the evaporator by the user, and an ambient temperature of an outdoor heat exchanger (condenser); a volume circulation rate detector for detecting a volume circulation rate Vcd of the refrigerant that actually circulates in a refrigerant circulation path of the refrigeration cycle apparatus; and an inverter for generating an AC current for driving the linear compressor; wherein the inverter is controlled so as to decrease a difference between the volume circulation rate Vco and the volume circulation rate Vcd.

Abstract: Disclosed is an apparatus and a method for controlling a driving of a reciprocating compressor for a refrigerator using a linear motor, in which a capacitance is varied according to a variation of a driving load, thereby improving a driving efficiency of the compressor. To this end, the apparatus for controlling a driving of a reciprocating compressor for a refrigerator using a linear motor comprises a first capacitor for attenuating an inductance of a coil wound on a motor; a second capacitor connected to the first capacitor in parallel; and a relay connected to the second capacitor in series to be turned on/off; and a microcomputer for outputting a control signal to turn on/off the relay according to the driving load of the refrigerator.

Abstract: A separate-type air conditioner that can reduce the effect of voltage fluctuations in a commercial power supply (12) on a compressor (11), reduce material costs while maintaining vibrations of an outdoor unit (2) at low levels, and improve working efficiency during an assembly operation. The outdoor unit (2) includes a voltage correction circuit (14) to keep an output voltage to the compressor (11) constant (optimum) irrespective of the voltage fluctuations in the commercial power supply (12).

Abstract: An improved control method for a vehicle air conditioning system including a refrigerant compressor and a condenser cooling fan adjusts the power consumption of the condenser cooling fan in a manner to minimize the combined power consumption of compressor and the condenser cooling fan while maintaining adequate cooling of the condensed refrigerant. When the air conditioning system is operating at less than full capacity, the combined power consumption of the compressor and the condenser cooling fan is determined for each of a series of operating intervals. The change in the combined power consumption from one operating interval to the next is computed to determine the effect of a prior cooling fan power adjustment, and the power level of the cooling fan is incrementally adjusted in the same direction as the prior adjustment so long as the prior adjustment resulted in at least a specified reduction of the combined power consumption.

Abstract: In a motor driving unit controlled by switching to/from PWM control from/to PAM control so that the maximum limit of motor speed can be increased and, at the same time, the unit can be operated at maximum efficiency during steady-state operation, the motor speed is controlled by maintaining the DC voltage command to the converter control circuit constant, but altering the conduction ratio command value to the inverter control circuit when the load to the motor is low, and by maintaining the conduction ratio command to the inverter control circuit constant, but altering the DC voltage command to the converter control circuit. There is a commutating phase control circuit that alters the commutating timing of the coil of the motor, and the motor is so controlled that the efficiency reaches the maximum limit during steady-state operation and the speed reaches the maximum limit during high-speed operation.

Abstract: In a communication control system for an air conditioner including an outdoor unit, plural indoor units and control equipment such as a remote controller, etc. which is connected to each indoor unit through a communication line, data communication being carried out between each indoor unit and the control equipment through the communication line, each indoor unit is equipped with a communication control device having a power source circuit 59 to which a power source voltage is supplied from a main power source, a communication superposing circuit for superposing communication data on the power source voltage, a transistor 54 for ON/OFF-controlling the supply of the power source voltage from the main power source to the communication superposing circuit, and a polarity coincidence circuit 63A that passes the output of the communication superposing circuit therethrough to the communication line and depolarizes the power source voltage from the external.

Abstract: An operation control apparatus and method of a linear compressor are disclosed. The operation control apparatus includes: an ambient temperature sensor unit for sensing a temperature around a refrigerator; a second microcomputer for outputting a control signal according to a temperature statue of a temperatures sensing unit for sensing an inner temperature of the refrigerator; a load driving unit for receiving an ON/OFF control signal for driving a linear compressor from the second microcomputer and outputting a drive signal to the linear compressor; a relay switched by the driving signal and supplying an AC power to a motor of the linear compressor; and a power supply unit for converting the AC power into a DC power and supplying power to each unit inside the linear compressor.

Abstract: A compressor includes a motor protector which stops the compressor's motor when it senses an out of specification condition. A diagnostic system monitors the status of the motor protector. The diagnostic system includes logic circuitry that diagnoses the type of problem the compressor is having based upon the running times and status of the motor in conjunction with the times and status of the motor protector.

Abstract: Disclosed is a temperature control device of a refrigerating apparatus and a method thereof, in which an operation rate of a compressor installed in the refrigerating apparatus is calculated and the compressor is controlled on the basis of the calculated operation rate of the compressor, thereby not needing to install outside air temperature detecting sensor and a damper and accurately controlling temperature of the refrigerating apparatus. To this end, there is provided a method for controlling temperature of a freezing chamber and a chilling chamber of the refrigerating apparatus having a compressor and a heat generating lamp, the method comprising the steps of: calculating an operation rate of the compressor installed in the refrigerating apparatus; and controlling an operation of the compressor on the basis of the calculated compressor operation rate.

Abstract: A separate-type air conditioner that can reduce the effect of voltage fluctuations in a commercial power supply (12) on a compressor (11), reduce material costs while maintaining vibrations of an outdoor unit (2) at low levels, and improve working efficiency during an assembly operation. The outdoor unit (2) includes a voltage correction circuit (14) to keep an output voltage to the compressor (11) constant (optimum) irrespective of the voltage fluctuations in the commercial power supply (12).

Abstract: In a hybrid compressor for a vehicle where a vehicle engine is stopped when the vehicle is temporally stopped, a pulley, a motor and a compressor can be driven in independent from each other, and are connected to a sun gear, planetary carriers and a ring gear of a planetary gear. A rotational speed of the motor is adjusted by a controller, so that a rotational speed of the compressor is changed with respect to a rotational speed of the pulley. Accordingly, production cost of the hybrid compressor and the size thereof can be reduced, while a cooling function can be ensured even when the vehicle engine is stopped.

Abstract: An air conditioner control system comprises an outdoor unit having a compressor controlled by pulse-width modulation, and a plurality of indoor units. Each of the plurality indoor units has an indoor control unit to calculate a respective required individual cooling capacity, and an indoor communication circuit unit through which the required individual cooling capacity calculated is transmitted. The outdoor unit has an outdoor control unit producing a duty cycle control signal in response to the required individual cooling capacity transmitted from the indoor units to control the capacity of the compressor, and an outdoor communication circuit unit to communicate the indoor communication circuit unit of respective ones of the plurality of indoor units.

Abstract: An air conditioner for air conditioning the interior of a compartment having a compressor, an electric motor, a detection device, a rotation speed sensor, and a controller is provided. The compressor compresses refrigerant gas and changes the displacement. The electric motor drives the compressor, and is capable of rotating at a constant reference rotation speed. The detection device detects information related to the thermal load on the air conditioner. The rotation speed sensor detects the rotation speed of the motor. The controller computes a target torque of the compressor at the reference rotation speed of the motor based on the thermal load information detected by the detection device, and computes an input current value to be supplied to the motor. The input current value corresponds to the target torque.

Abstract: A refrigerating compressor control circuit installed in a refrigerator and connected between AC power supply and the compressor motor of the refrigerator and adapted for controlling the operation of the compressor motor, the refrigerating compressor control circuit including a CPU (central processing unit), a current phase detector, a voltage phase detector, a trigger circuit having a TRIAC, a voltage level detector, a high current detector, a low current detector, an input filter, and an output filter. The CPU starts the compressor motor a length of time delay after a sudden shutdown, preventing damage to the compressor motor due to high pressure of cooling agent, and controls the output voltage value subject to the status of the load at the compressor motor.

Abstract: A refrigerating compressor control circuit installed in a refrigerator and connected between AC power supply and the compressor motor of the refrigerator and adapted for controlling the operation of the compressor motor, the refrigerating compressor control circuit including a CPU (central processing unit), a current phase detector, a voltage phase detector, a trigger circuit having a TRIAC, a voltage level detector, a high current detector, a low current detector, an input filter, and an output filter. The CPU starts the compressor motor a length of time delay after a sudden shutdown, preventing damage to the compressor motor due to high pressure of cooling agent, and controls the output voltage value subject to the status of the load at the compressor motor.

Abstract: A current sensor positioned on a power line monitors current draw associated with an electrical motor driven shaft based device, such as a scroll compressor. Mechanical vibrations in the scroll compressor force stress on the motor shaft of the scroll compressor, directly influencing current draw. By monitoring current draw, vibrations resulting from problems in the compressor, such as a broken mounting bracket, can be detected. A controller receives the current values and indicates if a current value exceeds a threshold current value or if a plurality of current values exceed a threshold value.

Abstract: The present invention provides an apparatus and method of operating a refrigeration system. The apparatus and method includes providing a fuel pressure monitoring device that is disposed along a fuel line, automatically shutting down the engine if the fuel pressure meets a first condition, restarting the engine, and operating the engine in an unrestricted mode if the fuel pressure monitoring device records a second condition and shutting down the engine if the fuel pressure monitoring device does not record the second condition. An apparatus and method of operating a diesel engine of a refrigeration system that is coupled to an inline fuel injection system is also disclosed.

Abstract: A system and method for monitoring and controlling an electrically driven transport refrigeration unit under varying operating conditions while maintain the system generator within its electric current and temperature limitations is disclosed. Specifically, the present invention the management of generator power through the combined use of controls for a suction modulation valve (an “SMV”), for diesel engine speed control, and for electronic expansion valve (“EXV”) superheat settings.

Abstract: An air conditioning system includes an engine driven compressor, and an independent electric motor driven compressor in a common housing. A controller adjusts the independent operation of the engine driven compressor and electric motor driven compressor in response to cooling demand input, and operational parameters of the engine and the battery, as well as optionally the electric motor driven compressor output and engine driven compressor output. A method of independently operating an engine driven compressor and electric motor driven compressor is also provided. The air-conditioning system, controller, and method are particularly useful in hybrid vehicles that use smaller displacement internal combustion engines and electric motor drive means.

Abstract: A current sensor positioned on a power line monitors current draw associated with an electrical motor driven shaft based device, such as a scroll compressor. Mechanical vibrations in the scroll compressor force stress on the motor shaft of the scroll compressor, directly influencing current draw. By monitoring current draw, vibrations resulting from problems in the compressor, such as a broken mounting bracket, can be detected. A controller receives the current values and indicates if a current value exceeds a threshold current value or if a plurality of current values exceed a threshold value.

Abstract: A data acquisition system and method includes monitoring a cooling system having a refrigerant compressor, evaporator, and condensor, and employs a number of sensors to monitor various operating parameters of the system. A database stores predefined operating parameters for a plurality of cooling systems. The operating parameters are provided to a computer, which compares the provided operating parameters of the monitored cooling system with the predefined operating parameters to provide diagnostic results for the monitored cooling system.

Abstract: To provide a transportable cooling unit for maintaining a transport volume at a defined temperature, comprising a closed cooling circuit and a controller sensing a temperature present within said transport volume and controlling said cooling circuit so as to provide the cooling power demanded at said evaporator for maintaining said defined temperature and minimizing energy consumption, said controller operates said closed cooling circuit between a minimum possible cooling power and a maximum possible cooling power in a sequence of different operational stages, said controller further operates said closed cooling circuit in each one of at least two upper operational stages at a compressor speed related cooling capacity different said other upper operational stages and within said respective upper operational stages said controller operates a compressor in an uninterrupted mode and adjusts said cooling power stepless speed control of said compressor.

Abstract: An air conditioning system for a vehicle comprises a compressor, an electric motor for driving the compressor, a device for variably controlling a rotational speed of a drive shaft of the compressor based on a target rotational speed of the drive shaft of the compressor; a device for limiting the rotational speed of the drive shaft of the compressor to less than the target rotational speed of the compressor when a first value of a current detected at the electric motor is greater than or equal to a first predetermined value; and a device for terminating the limiting of the rotational speed of the drive shaft of the compressor when a second value of the detected current is less than a second predetermined value during the limit operation.

Abstract: A method for controlling corresponding energy supply of a heat source unit of a refrigeration air conditioning system based on required energy value calculated from output power value mainly includes a controller coupled with a heat exchanger unit at the refrigeration air conditioning loading side that matches a heat source unit of a refrigeration air conditioning system. The controller includes a power value detection unit to detect the delivered loading power value, and through a center micro processing unit to process air conditioning required energy value which is transferred to a refrigeration air conditioning required energy value calculation unit to accumulate total required energy value. The total required energy value is dynamically fed to a heat source controller to control optimal heat source supply of the heat source unit such that the system is maintained the optimum operation condition to effectively save energy and achieve higher operation efficiency.

Abstract: Methods and apparatus for monitoring power outages in a household appliance such as a refrigerator are disclosed. According to the method, a household appliance determines a prior occurrence of a power outage to the appliance. The household appliance then computes a duration of the power outage. Further, the household appliance alerts a user of the duration of the power outage.

Abstract: The invention relates to a switch cabinet or cover with an air-conditioning unit, which comprises a cooling circuit system with an evaporator and a condenser. The evaporator has an integral air circuit, connected spatially with the interior of the switch cabinet and through which the air in the interior of the switch cabinet may be forced, by means of a blower. The condenser is in contact with the remaining components of the cooling circuit, by means of refrigerant lines. According to the invention, in order to reduce emissions from the air-conditioner, due to environmental damage considerations, the evaporator, together with the dedicated blower, is integrated in an evaporator unit, attached to the switch cabinet. The condenser, together with a dedicated blower, is integrated in a condenser unit, whereby the condenser unit is spatially separate from the evaporator unit and from the switch cabinet.

Abstract: To provide a transportable cooling unit for maintaining a transport volume at a defined temperature, comprising a closed cooling circuit and a controller sensing a temperature present within said transport volume and controlling said cooling circuit so as to provide the cooling power demanded at said evaporator for maintaining said defined temperature and minimizing energy consumption, said controller operates said closed cooling circuit between a minimum possible cooling power and a maximum possible cooling power in a sequence of different operational stages, said controller further operates said closed cooling circuit in each one of at least two upper operational stages at a compressor speed related cooling capacity different said other upper operational stages and within said respective upper operational stages said controller operates a compressor in an uninterrupted mode and adjusts said cooling power stepless speed control of said compressor.

Abstract: An air conditioner capable of improving its assembling efficiency and reducing material costs. The air conditioner reduces the effects of the fluctuation in commercial line voltage (12) on the supply voltage to a compressor (11), while reducing the vibrations of its outdoor unit (2). The outdoor unit (2) is provided with a voltage correction circuit (14) that maintains the output voltage to the compressor (11) constant (optimal) regardless of the changes in voltage on commercial power supply line (12).

Abstract: A vehicle air conditioning system controls an engine and an air conditioner according to an air-conditioner load to thereby improve fuel economy and drivability of the vehicle. A higher compressor torque between a first estimated compressor torque, which is estimated according to the outside air temperature and the vehicle speed, and a second estimated compressor torque, which is estimated according to the refrigerant pressure, is adopted as an estimated compressor torque. When an air conditioner control switch is ON, an operational status of an engine and a compressor are controlled according to the adopted estimated compressor torque.