Ventilating and air conditioning system for a passenger vehicle

Claim 1

IN A VENTILATING AND AIR CONDITIONING SYSTEM FOR A VEHICLE HAVING SIDE AND END WALLS, A CEILING AND ROOF THEREOVER, FRESH AIR INTAKE AND EXHAUST AIR OPENINGS IN SAID ROOF, A FLOOR, AND DOORS IN THE SIDE WALLS DEFINING A PASSENGER COMPARTMENT, A DUAL FLOW CIRCULATING FAN UNIT MOUNTED IN THE CEILING AND ROOF, SAID FAN UNIT COMPRISING A HOUSING, JUXTAPOSED DUCT MEANS EXTENDING FROM SAID HOUSING TO SAID AIR INTAKE AND EXHAUST AIR OPENINGS, AN INTAKE PASSAGEWAY, A DISCHARGE PASSAGEWAY, A PLENUM CHAMBER, A FAN UNIT MOUNTED IN SAID HOUSING HAVING A MOTOR AND A DUAL FLOW FAN BLADE WITH SEPARATE INTAKE AND DISCHARGE BLADES, A FAN INTAKE OPENING COMMUNICATING WITH SAID INTAKE BLADES AND SAID INTAKE PASSAGEWAY, A FAN DISCHARGE OPENING COMMUNICATING WITH SAID DISCHARGE BLADES AND SAID DISCHARGE PASSAGEWAY, SAID INTAKE PASSAGEWAY ALWAYS IN COMMUNICATION WITH SAID PLENUM CHAMBER, OPENING MEANS IN SAID HOUSING COMMUNICATING WITH SAID ADJACENT DUCT MEANS, AND DAMPER MEANS FOR SAID OPENING MEANS SELECTIVELY INTERCOMMUNICATING SAID PLENUM CHAMBER AND SAID DISCHARGE PASSAGEWAY WHEN CLOSED AND INTERCOMMUNICATING THE PLENUM CHAMBER WITH THE EXHAUST AIR OPENING DUCT MEANS AND THE DISCHARGE PASSAGEWAY WITH THE FRESH AIR INTAKE OPENING DUCT MEANS WHEN OPEN.