Heating or air-conditioning system for a motor vehicle

A compact heating or air-conditioning system providing separately conditioned air to four individual zones in a motor vehicle passenger compartment, comprising:

• a housing;
• a generally planar heater located in said housing, said heater having a heated air exit surface and having a bottom and a top end defining a height of the heater, and said heater being oriented generally vertically within the housing;
• an interior partition in said housing defining an air inlet opening for the heater;
• first, second, third, and fourth parallel cool-air sub-ducts extending below the heater;
• first, second, third, and fourth axially elongated air mixing spaces communicating respectively with and positioned downstream of the first, second, third, and fourth sub-ducts, the first, second, third, and fourth mixing spaces having an air inlet at the bottom end of the heater and having an air exit at the top end of the heater and being defined by the heated air exit of the heater and a portion of said housing extending in opposed relationship to the heated air exit surface of the heater, whereby the first, second, third, and fourth mixing spaces extend parallel to the exit surface of the heater over substantially the full height of the heater, the first, second, third, and fourth mixing spaces receive air heated by the heater immediately downstream of the heater and receive cool air from the first, second, third, and fourth sub-ducts at the bottom of the heater, thereby defining an air-flow path substantially parallel to the exit surface of the heater, receiving air at said air inlet at the bottom end of the heater and discharging mixed heated air at said air exit at the top end of the heater;
• wherein at least one mixing space further includes a nonreturn flap, the nonreturn flap including a plurality of louvered vanes disposed between the heater and the at least one mixing space, and wherein the nonreturn flap, in a closed position, covers a portion of an air exit surface of the heater;
• and
• first, second, third, and fourth air control elements for determining respective quantities of the heated air and cool air to be mixed, the first, second, third, and fourth air control elements being disposed upstream of the heater, wherein each of the first, second, third, and fourth air control elements is movable between a first position in which the air control element substantially blocks cool air from entering the respective sub-duct and a second position in which the respective air control element blocks a portion of the heater inlet and fully opens the respective sub-duct, wherein the first, second, third and fourth air control elements are located near the bottom end of the heater and the upper portion of the upstream side of the heater is continuously covered by a cover member,
• wherein each of the first, second, third, and fourth air mixing spaces is adapted to communicate with at least one mixed air duct and at least one air outlet nozzle for guiding mixed air to a respective conditioned zone to provide four separate conditioned zones in the vehicle.