Air Duct In Front Heater And A/C Unit

The overview shows a LHD vehicle as an example. The component layout is a mirror image for RHD vehicles.

• Depending on vehicle equipment, there are different versions of the A/C system. Make sure to use the correct version and pay attention to the allocation of different components. Refer to Parts Information.
• In order to show the air duct in the air intake housing and in the Heater and A/C unit, both of these components are shown cut along lines "A - A" and "B - B" and "C- C".
• On vehicles with glove compartment cooling, the cooled air comes directly past the evaporator into the glove compartment -Item 11-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Evaporator.
• For the temperature of the air from the front vents to be regulated separately, separator walls are installed in the front heater and A/C unit (not shown in detail here).

Fig 1: Exploded View Of Air Duct In Front Heater And A/C Unit

Courtesy of AUDI OF AMERICA, LLC

1. Front Heater and A/C Unit Evaporator and Air Distribution Housing
   • There are different versions. Refer to the Parts Information.
   • Overview. Refer to OVERVIEW - HEATER AND A/C UNIT .
2. Front Heater and A/C Unit Air Intake Housing
3. Fresh Air Intake
   • The air is extracted out of the plenum chamber. Refer to FRESH AIR INTAKE, REMOVING AND INSTALLING .
4. Air Intake from the Vehicle Interior (in Recirculating Air Mode)
   • The air is drawn out of the front passenger footwell when the air recirculation door under the glove compartment is open
   • In this illustration, the air recirculation door is shown in the "closed" position.
5. Fresh Air Blower -V2- with Fresh Air Blower Control Module -J126-
6. Air Vent to Left Instrument Panel Vent
7. Air Vent to Left Footwell Vent
8. Air Outlet to the Right Instrument Panel Vent
   • Depending on vehicle equipment also to wide vent
9. Air Vent to Right Footwell Vent
10. Dust and Pollen Filter
    • There are different versions. Refer to the Parts Information.
    • Removing and Installing. Refer to DUST AND POLLEN FILTER, REMOVING AND INSTALLING .
11. Evaporator
12. Heater Core for the Heater
    • Removing and Installing. Refer to HEATER CORE, REMOVING AND INSTALLING .
13. Zone Partition Grille or Auxiliary Heater Heating Element -Z35- (with the Auxiliary Heater Control Module -J604-)
    • The Auxiliary Heater Heating Element -Z35- (with the Auxiliary Heater Control Module -J604-)is installed depending on vehicle equipment. Refer to Auxiliary Heater Control Module -J604- (WITH Auxiliary Heater Heating Element -Z35-) REMOVING AND INSTALLING .
    • For vehicles without Auxiliary Heater Heating Element -Z35-, zone partition grille is installed
14. Front Left Mixing Chamber for Warmed and not Warmed Air
    • Via the various temperature control doors, a certain portion of the air is directed through or past the heater core (and the Auxiliary Heater Heating Element -Z35- or the zone partition grille)
    • The temperature control doors for the front are not shown here
15. Separator between the Driver and Front Passenger Side
    • Separates the air duct to the left and right vents and is responsible for different air temperatures coming out of the vent. Depending on the position of the particular temperature doors.
16. Left Front Area Air Vent
    • Depending on the setting, the warmed or cooled air can be directed to the vents.
    • The rear temperature control door is not shown here
    • On a heater and A/C unit for a "Low" or "Mid" A/C system the door for the air vent in the rear (Item 16-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Left Front Area Air Vent, -Item 17-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Center Front Area Air Vent and -Item 18-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Right Front Area Air Vent) are joined with each other via a curved washer depending on the position as closed or open (only the door -Item 16-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Left Front Area Air Vent and -Item 18-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Right Front Area Air Vent) via the shaft.
    • On a heater and A/C unit for a "Mix" or "High" A/C system the doors for the air vent in the front area -Item 16-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Left Front Area Air Vent, -Item 17-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Center Front Area Air Vent and -Item 18-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Right Front Area Air Vent are closed or opened at the same time (they are attached with each other via the shaft).
17. Center Front Area Air Vent
    • Depending on the setting, the warmed or cooled air can be directed to the vents.
    • The rear temperature control door is not shown here
    • On a heater and A/C unit for a "Low" or "Mid" A/C system the door for the air vent in the rear (Item 16-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Left Front Area Air Vent, -Item 17-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Center Front Area Air Vent and -Item 18-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Right Front Area Air Vent) are joined with each other via a curved washer depending on the position as closed or open (only the door -Item 16-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Left Front Area Air Vent and -Item 18-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Right Front Area Air Vent) via the shaft.
    • On a heater and A/C unit for a "Mix" or "High" A/C system the doors for the air vent in the front area -Item 16-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Left Front Area Air Vent, -Item 17-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Center Front Area Air Vent and -Item 18-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Right Front Area Air Vent are closed or opened at the same time (they are attached with each other via the shaft).
18. Right Front Area Air Vent
    • Depending on the setting, the warmed or cooled air can be directed to the vents.
    • The rear temperature control door is not shown here
    • On a heater and A/C unit for a "Low" or "Mid" A/C system the door for the air vent in the rear (Item 16-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Left Front Area Air Vent, -Item 17-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Center Front Area Air Vent and -Item 18-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Right Front Area Air Vent) are joined with each other via a curved washer depending on the position as closed or open (only the door -Item 16-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Left Front Area Air Vent and -Item 18-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Right Front Area Air Vent) via the shaft.
    • On a heater and A/C unit for a "Mix" or "High" A/C system the doors for the air vent in the front area -Item 16-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Left Front Area Air Vent, -Item 17-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Center Front Area Air Vent and -Item 18-  AIR DUCT IN FRONT HEATER AND A/C UNIT List Item:Right Front Area Air Vent are closed or opened at the same time (they are attached with each other via the shaft).
19. Front Right Mixing Chamber for Warmed and not Warmed Air
    • Via the various temperature control doors, a certain portion of the air is directed through or past the heater core (and the Auxiliary Heater Heating Element -Z35- or the zone partition grille)
    • Temperature control doors for the front are not shown here
20. Connection for Glove Compartment Cooling Air Duct Hose
    • On vehicles without the optional equipment of "glove compartment cooling", he opening in the heater and A/C unit is sealed with a cap. Refer to AIR GUIDE FOR GLOVE COMPARTMENT COOLING, REMOVING AND INSTALLING .
    • Glove Compartment Cooling Air Duct Hose, Checking, Removing and Installing. Refer to AIR GUIDE FOR GLOVE COMPARTMENT COOLING, REMOVING AND INSTALLING .