|Subassemblies of the heating-/air conditioning|
|Suction part with air circulation flap||Above right|
|Multi-stage radial flow pump||Right|
|Replaceable pollen filter||Center|
|Heating/air-conditioning heat exchanger||Rear at the left|
|Flap part with servo-motors||Front at the left|
|This device allows up to three air-conditioning zones through |
|Air-conditioning/heating mostly automatically regulated|
Because below a certain speed the ventilation no longer functions without the fan, this nearly always runs permanently. On it's way into the interior, the air has to be filtered and warmed or cooled. Where the air now comes out, can be freely chosen. The choice of either heating the air or cooling it takes place in the air-conditioning through a control device which, switches either the air-conditioning on or operates the electric heating valve, here's one from a utility vehicle (see picture 3).
|Ventilating fan, filter, heat exchanger, flap part|
At the top right, the air is drawn in and then transported to the middle. The radial flow pump can be seen clearly. Above that is the flap, from where the air, when in circulation operation, is drawn from the interior. From the blower it goes through the filter, at the rear on the left side, to the respective vertically installed heater and the evaporator. Because here a great deal of condensation gathers, there is also a water drain, which cannot be seen here. The flaps with a servo motor direct the air to the top, to the side or down to the foot area. Parts of the operating device can even be partially seen.
|Strong, silent, multi-stage radial pump|
Most car bodies have such a streamlined design, that the outside air, at urban speeds, does not flow into the interior by itself. Apart from that, a slight high pressure in the interior does make sense. For this reason, the strong blower at the bottom right is necessary. Nowadays, a very effective radial fan, which in this case, sucks in the air from above and allows it to flow to the left at a tangent, into the larger part of the air-box. In the above figure, the intake duct with a rounded edge, can clearly be seen at he top in the middle. The relatively short vanes of the rotor press the air outwards. What is also important here, is that there is little noise build-up.
|Flat, even heating, little amount of pressure drop|
One would not think, that in such a well concealed component like the heater radiator (see picture 2), improvements are possible. Nonetheless, there certainly is room for improvement. By using flat piping, the surrounding plating is better supplied with heat. The manufacturer advertises an even heat distribution over the whole surface. The construction has become more compact, thus, requiring less installation space. Last but not least, the pressure-drop on the coolant side has been reduced, which, in turn, lowers the performance demands on the water-pump. 09/10