P83.20-2139-76
Operating condition: Heating
A Fresh air (filtered)
C Warm air
E Defroster flap
F Footwell flap
M Center nozzle and lateral nozzles
W Wiper rest heater
2 Dust filter
5 Heating system heat exchanger
6 Blending air flap
7 Blower
8 Recirculated air flap
9 Electric PTC heater booster
(with OM668 only)
Operating condition: Heating
Function
During heater operation, the fresh air (A) is intaken by the blower (7) via the dust filter (2) into the heater housing. The air, which is cleaned by the dust filter (2), is subsequently conducted through the heat exchanger (5).
This air conduction is controlled via the setting of the blend air flap (6).
The fresh air (A) is warmed up in the heated heat exchanger (5).
As a result of the high level of efficiency in the case of direct injection diesel engines, the fresh air (A) cannot be heated sufficiently in the heated heat exchanger (5). The fresh air (A) is therefore conducted further through the electric PTC heater booster (9), where it is additionally heated by heating elements.
The warm air (C) is conducted via the air outlets (E, F, M and W) into the vehicle interior.
The recirculating air flap (8) is closed.
P83.20-2140-76
Operating condition: No heating
A Fresh air (filtered)
E Defroster flap
F Footwell flap
M Center nozzle and lateral nozzles
W Wiper rest heater
2 Dust filter
5 Heating system heat exchanger
6 Blending air flap
7 Blower
8 Recirculated air flap
9 Electric PTC heater booster
(with OM668 only)
Operating condition: "No heating"
Function
In the "no heating" operating status, the fresh air (A) is intaken by the blower (7) via the dust filter (2) into the heater housing. The air, which is cleaned by the dust filter (2), is subsequently conducted around the heat exchanger (5) and the electric PTC heater booster (9). This air conduction is controlled via the setting of the blend air flap (6).
The fresh air (A) is guided directly via the air outlets (E, F, M and W) into the vehicle interior.
The recirculating air flap (8) is closed.
P83.20-2141-76
Operating condition: No "recirculating air" heating
A Recirculation air (unfiltered)
E Defroster flap
F Footwell flap
M Center nozzle and lateral nozzles
W Wiper rest heater
2 Dust filter
5 Heating system heat exchanger
6 Blending air flap
7 Blower
8 Recirculated air flap
9 Electric PTC heater booster
(with OM668 only)
Operating condition: "No recirculating air heating"
Function
In the "no recirculating air heating" operating status, the recirculating air (A) is intaken into the heater housing by the blower (7) from the vehicle interior via the open recirculating air flap (8). The air, which is not cleaned by the dust filter (2), is subsequently conducted around the heat exchanger (5) and the electric PTC heater booster (9). This air conduction is controlled via the setting of the blend air flap (6).
The recirculating air (A) is guided directly via the air outlets (E, F, M and W) into the vehicle interior.
The fresh air supply is blocked by the recirculating air flap (8).