Method and apparatus for reducing the temperature of air in the cabin of a stationary vehicle

A method of reducing cabin air temperature in a vehicle comprising a cabin, and associated with the cabin, an air conditioning means comprising a compressor for a refrigerant fluid, a fan for delivering a stream of air into the cabin and an evaporator for transferring heat from said stream of air to said refrigerant fluid, wherein said method includes the steps of:

• detecting the temperature of the internal air in the cabin;
• detecting the temperature of the external air outside the cabin;
• and controlling the apparatus, in response to said detected temperatures, in three successive stages as follows:
• in the first stage, driving the fan so as to deliver external air into the cabin when the internal temperature exceeds the external temperature by at least a predetermined limiting amount;
• in the second stage, driving the compressor in a first compressor regime when the condition for the first operating stage is absent but the internal temperature is greater than a predetermined threshold value;
• and
• in the third stage, driving the compressor in a second compressor regime such that energy consumption and the heat exchange capacity of the evaporator are reduced as compared with the second stage, when the conditions for the first and second stages are absent, wherein, in said first and second stages, the fan is driven at a first fan speed, and in said third stage it is driven at a second fan speed lower than the first fan speed.

An apparatus for installation in a vehicle having a cabin and for reducing the cabin air temperature in said vehicle, the vehicle having air conditioning apparatus comprising a compressor for a refrigerant fluid, a fan for delivering a stream of air into the cabin and an evaporator associated with said compressor for transferring heat from the stream of air to the refrigerant fluid, an internal temperature sensor for detecting the internal temperature of the vehicle, an external temperature sensor for detecting the temperature of air external to the vehicle, and control means connected to the fan, compressor and sensors, so as to control the fan and the compressor in response to signals from the said sensors, the apparatus controlled in subsequent first, second and third stages, the first stage driving the fan so as to deliver external air into the cabin when the internal temperature exceeds the external temperature by at least a predetermined limiting amount;

• the second stage driving the compressor in a first compressor regime when the condition for the first operating stage is absent but the internal temperature is greater than a predetermined threshold value;
• and the third stage driving the compressor in a second compressor regime such that energy consumption and the heat exchange capacity of the evaporator are reduced as compared with the second stage, when the conditions for the first and second stages are absent, the apparatus further comprising timing means for automatically interrupting operation of the air conditioning apparatus after a predetermined time.

An apparatus for installation in a vehicle having a cabin and for reducing the cabin air temperature in said vehicle, the vehicle having air conditioning apparatus comprising a compressor for a refrigerant fluid, a fan for delivering a stream of air into the cabin and an evaporator associated with said compressor for transferring heat from the stream of air to the refrigerant fluid, an internal temperature sensor for detecting the internal temperature of the vehicle, an external temperature sensor for detecting the temperature of air external to the vehicle, and control means connected to the fan, compressor and sensors, so as to control the fan and the compressor in response to signals from the said sensors, the apparatus controlled in subsequent first, second and third stages, the first stage driving the fan so as to deliver external air into the cabin when the internal temperature exceeds the external temperature by at least a predetermined limiting amount;

• the second stage driving the compressor in a first compressor regime when the condition for the first operating stage is absent but the internal temperature is greater than a predetermined threshold value;
• and the third stage driving the compressor in a second compressor regime such that energy consumption and the heat exchange capacity of the evaporator are reduced as compared with the second stage, when the conditions for the first and second stages are absent, the apparatus further comprising programming means for starting the air conditioning apparatus at a predetermined time.

An apparatus for installation in a vehicle having a cabin and for reducing the cabin air temperature in said vehicle, the vehicle having air conditioning apparatus comprising a compressor for a refrigerant fluid, a fan for delivering a stream of air into the cabin and an evaporator associated with said compressor for transferring heat from the stream of air to the refrigerant fluid, an internal temperature sensor for detecting the internal temperature of the vehicle, an external temperature sensor for detecting the temperature of air external to the vehicle, and control means connected to the fan, compressor and sensors, so as to control the fan and the compressor in response to signals from the said sensors, the apparatus controlled in subsequent first, second and third stages, the first stage driving the fan so as to deliver external air into the cabin when the internal temperature exceeds the external temperature by at least a predetermined limiting amount;

• the second stage driving the compressor in a first compressor regime when the condition for the first operating stage is absent but the internal temperature is greater than a predetermined threshold value;
• and the third stage driving the compressor in a second compressor regime such that energy consumption and the heat exchange capacity of the evaporator are reduced as compared with the second stage, when the conditions for the first and second stages are absent, the apparatus further comprising remote control means for starting the operation of the air condition apparatus from a distance.

An apparatus for installation in a vehicle having a cabin and for reducing the cabin air temperature in said vehicle, the vehicle having air conditioning apparatus comprising a compressor for a refrigerant fluid, a fan for delivering a stream of air into the cabin and an evaporator associated with said compressor for transferring heat from the stream of air to the refrigerant fluid, an internal temperature sensor for detecting the internal temperature of the vehicle, an external temperature sensor for detecting the temperature of air external to the vehicle, and control means connected to the fan, compressor and sensors, so as to control the fan and the compressor in response to signals from the said sensors, the apparatus controlled in subsequent first, second and third stages, the first stage driving the fan so as to deliver external air into the cabin when the internal temperature exceeds the external temperature by at least a predetermined limiting amount;

• the second stage driving the compressor in a first compressor regime when the condition for the first operating stage is absent but the internal temperature is greater than a predetermined threshold value;
• and the third stage driving the compressor in a second compressor regime such that energy consumption and the heat exchange capacity of the evaporator are reduced as compared with the second stage, when the conditions for the first and second stages are absent, the apparatus further comprising a fan motor coupled with the fan for driving the fan, a compressor motor coupled with the compressor for driving the compressor, low tension power supplying means connected with the fan motor for supplying the fan motor, and high tension supply means connected with the compressor motor for supplying the compressor motor.

An apparatus for installation in a vehicle having a cabin and for reducing the cabin air temperature in said vehicle, the vehicle having air conditioning apparatus comprising a compressor for a refrigerant fluid, a fan for delivering a stream of air into the cabin and an evaporator associated with said compressor for transferring heat from the stream of air to the refrigerant fluid, an internal temperature sensor for detecting the internal temperature of the vehicle, an external temperature sensor for detecting the temperature of air external to the vehicle, and control means connected to the fan, compressor and sensors, so as to control the fan and the compressor in response to signals from the said sensors, the apparatus controlled in subsequent first, second and third stages, the first stage driving the fan so as to deliver external air into the cabin when the internal temperature exceeds the external temperature by at least a predetermined limiting amount;

• the second stage, driving the compressor in a first compressor regime when the condition for the first operating stage is absent but the internal temperature is greater than a predetermined threshold value;
• and the third stage driving the compressor in a second compressor regime such that energy consumption and the heat exchange capacity of the evaporator are reduced as compared with the second stage, when the conditions for the first and second stages are absent, the apparatus installed in an electrically propelled vehicle having a traction battery, a compressor motor coupled to the compressor for driving the latter, and means connecting the traction battery to the compressor motor whereby to drive the latter.