Abstract: An HVAC system for a work vehicle having an operator compartment for a vehicle operator, the system including a heating system, a compartment pressurizer blower, a compartment recirculation blower, a temperature sensor, and an operating mode switch, each operably coupled to an electronic circuit, wherein the circuit is configured to reduce pressurizer blower output when the operator selects high output from the heating system under certain predetermined temperature and conditions and operating modes to improve HVAC system performance.

Abstract: An HVAC system for a work vehicle having an operator cab includes a first chamber having an for receiving airflow exterior of the cab. The inlet is adjacent to a first source for moving air for use independent of the HVAC system, the inlet arranged to cause a first change of direction of airflow inside the first chamber. The first chamber resulting in both a first air pressure reduction and a first reduction of airflow velocity while inside the first chamber sufficient to reduce an amount of particles entrained in the airflow while the particles are within the first chamber. A second chamber in fluid communication with the first chamber and configured to cause both a second change of direction and a third change of direction of airflow while inside of the second chamber prior to reaching a third chamber for mixing air flow with recirculated air from the cab.

Abstract: An HVAC system for a work vehicle having an operator cab including a system positioned substantially within the cab behind and below an operator's chair. A portion of the system has at least one inlet, and a plurality of outlets positioned in front of the operator's chair. The system includes a filter configured to be easily maintained in its substantially horizontal position during removal so that debris retained on the upper surface of the filter does not fall into a portion of the HVAC system or the cab when the filter is removed therefrom.

Abstract: An HVAC system for a work vehicle having an operator cab includes a first chamber having an for receiving airflow exterior of the cab. The inlet is adjacent to a first source for moving air for use independent of the HVAC system, the inlet arranged to cause a first change of direction of airflow inside the first chamber. The first chamber resulting in both a first air pressure reduction and a first reduction of airflow velocity while inside the first chamber sufficient to reduce an amount of particles entrained in the airflow while the particles are within the first chamber. A second chamber in fluid communication with the first chamber and configured to cause both a second change of direction and a third change of direction of airflow while inside of the second chamber prior to reaching a third chamber for mixing air flow with recirculated air from the cab.

Abstract: An HVAC system for a work vehicle having an operator compartment for a vehicle operator, the system including a heating system, a compartment pressurizer blower, a compartment recirculation blower, a temperature sensor, and an operating mode switch, each operably coupled to an electronic circuit, wherein the circuit is configured to reduce pressurizer blower output when the operator selects high output from the heating system under certain predetermined temperature and conditions and operating modes to improve HVAC system performance.

Abstract: An HVAC system for work vehicle having an operator compartment for an operator is disclosed. The HVAC system includes a pressurizer blower and an air-conditioning system coupled to an electronic circuit. The electronic circuit is configured to reduce the output of the pressurizer blower when the operator selects a high output from the air-conditioning system. The HVAC system is also configured to provide defog operation in both a manual mode and an automatic mode of operation. The HVAC system is configured to reset the defog operation when the vehicle ignition is turned off or turned back on. The HVAC system is also configured not to reset the defog operation when the operator switches rapidly between the automatic mode and the manual mode of operation.

Abstract: A cut-out circuit for an air conditioner protects the air conditioning system components when subjected to low pressure conditions, without manually resetting the system after low pressure cut-out. The cut-out circuit preferably includes a relay, connectable to a voltage source through a normally closed low pressure switch to a compressor clutch, the relay operable in a closed state to output a voltage from the voltage source through the low pressure switch to the clutch, and in an open state to interrupt the voltage. The low pressure switch may open responsive to a low pressure condition interrupting voltage flow to the clutch. The circuit includes a normally open high pressure switch, connected to the relay and a voltage source, operable to close responsive to a high pressure condition, to output a voltage from a voltage source to the relay for changing the relay operating state to open.

Abstract: A controller area network based climate control system for a work machine, and a method of operation of the same, which advantageously and economically integrates into and utilizes the resources and capabilities of a CAN of a work machine, including, but not limited to, shared data from other systems of the machine, particularly engine data including engine operating speed and temperature, for controlling climate control system operation, as well as for troubleshooting and diagnosing problems.

Abstract: An HVAC system for work vehicle having an operator compartment for an operator is disclosed. The HVAC system includes a pressurizer blower and an air-conditioning system coupled to an electronic circuit. The electronic circuit is configured to reduce the output of the pressurizer blower when the operator selects a high output from the air-conditioning system. The HVAC system is also configured to provide defog operation in both a manual mode and an automatic mode of operation. The HVAC system is configured to reset the defog operation when the vehicle ignition is turned off or turned back on. The HVAC system is also configured not to reset the defog operation when the operator switches rapidly between the automatic mode and the manual mode of operation.

Abstract: An HVAC system for work vehicle having an operator compartment for an operator is disclosed. The HVAC system includes a pressurizer blower and an air-conditioning system coupled to an electronic circuit. The electronic circuit is configured to reduce the output of the pressurizer blower when the operator selects a high output from the air-conditioning system. The HVAC system is also configured to provide defog operation in both a manual mode and an automatic mode of operation. The HVAC system is configured to reset the defog operation when the vehicle ignition is turned off or turned back on. The HVAC system is also configured not to reset the defog operation when the operator switches rapidly between the automatic mode and the manual mode of operation.

Abstract: A variable air circulation system for the cab enclosure of an off-highway vehicle is disclosed and described. The system provides for adjustment of the ratio between fresh air circulation and recirculation of cab air. Fresh air is introduced into the cab through a fresh air inlet having a fresh air filter therein. The air inlet leads to a circulation conduit. When a cab door is opened, a valve to the conduit is opened. When the door is closed, the air pulse created in the cab is effective, through the valve, to dislodge dust and dirt from the filter.

Abstract: A fixed air circulation system for the cab enclosure of an off-highway vehicle is disclosed. Fresh air is introduced into the cab through a fresh air inlet having a fresh air filter therein. The air inlet leads, through a manifold or fresh air duct, to the inside of the operator's compartment. When a cab door is opened, a bypass valve to the conduit is opened. When the door is closed, the air pulse created in the cab is effective, through the bypass valve or normal openings with the blower off, to dislodge dust and dirt from the filter.

Abstract: A fixed air circulation system for the cab enclosure of an off-highway vehicle is disclosed. Fresh air is introduced into the cab through a fresh air inlet having a fresh air filter therein. The air inlet leads, through a manifold or fresh air duct, to the inside of the operator's compartment. When a cab door is opened, a bypass valve to the conduit is opened. When the door is closed, the air pulse created in the cab is effective, through the bypass valve or normal openings with the blower off, to dislodge dust and dirt from the filter.

Abstract: A variable air circulation system for the cab enclosure of an off-highway vehicle is disclosed and described. The system provides for adjustment of the ratio between fresh air circulation and recirculation of cab air. Fresh air is introduced into the cab through a fresh air inlet having a fresh air filter therein. The air inlet leads to a circulation conduit. When a cab door is opened, a valve to the conduit is opened. When the door is closed, the air pulse created in the cab is effective, through the valve, to dislodge dust and dirt from the filter.

Abstract: A cut-out circuit for an air conditioner, which protects the air conditioning system components when subjected to low pressure conditions, without requiring manually resetting the system after low pressure cut-out, but which requires resetting after high pressure cut-out. The cut-out circuit includes a device, preferably a relay, connectable to a voltage source and through a normally closed low pressure switch to a compressor clutch, the relay being operable in a closed state to output a voltage from the voltage source through the low pressure switch to the clutch, and in an open state to cease outputting or interrupting the voltage. The low pressure switch is operable to open responsive to a low pressure condition, to interrupt voltage flow to the clutch.

Abstract: A method and apparatus for providing a cab pressure drop warning to an off-road machine operator and instructions for increasing the cab pressure and for providing incentive to correct the pressure drop, the method including comparing ambient and cab pressures and threshold pressure (i.e., the ambient plus a differential value), causing a vehicle operation disruption for at least a short period during which the operator may elect to remedy the cab pressure drop.

Abstract: A method and apparatus for providing a cab pressure drop warning to an off-road machine operator and instructions for increasing the cab pressure and for providing incentive to correct the pressure drop, the method including comparing ambient and cab pressures and threshold pressure (i.e., the ambient plus a differential value), causing a vehicle operation disruption for at least a short period during which the operator may elect to remedy the cab pressure drop.

Abstract: A method and apparatus for providing a cab pressure drop warning to an off-road machine operator and instructions for increasing the cab pressure and for providing incentive to correct the pressure drop, the method including comparing ambient and cab pressures and threshold pressure (i.e., the ambient plus a differential value), causing a vehicle operation disruption for at least a short period during which the operator may elect to remedy the cab pressure drop.

Abstract: A combine including an improved HVAC control system. The frame of the combine supports an operator cab, a harvesting head and the other operational systems of the combine. The control system includes an operator control and a heat exchanger located in the cab. The control system also includes at least one sensor disposed to sense at least one of an ambient air temperature, a cab air temperature and solar loading, and to produce at least one sensed signal representative thereof. The operator control is configured to produce a set-point signal representative of a desired cab air temperature. An interface circuit is electromagnetically coupled to the valve assembly, the operator control, and the at least one sensor. A cooling coil may also be located in the cab, wherein the interface circuit is electromagnetically coupled to the associated coolant compressor.

Abstract: An air handling system for the cab of a vehicle includes a cab roof having inner and outer roof members spaced from each other so as to form a first chamber. The cab roof has a first plurality of openings around its periphery through which air may be drawn into the first chamber. The cab roof together with a headliner for the cab form a second chamber. A first opening in the inner roof member allows air to flow into the second chamber, and an air handling unit located between the headliner and the cab roof receives air from the second chamber and discharges it through a first opening in the headliner into the cab interior.