Quote Originally Posted by Mirek View Post
Listen to br21, he knows.

Please follow this small example.

It's cold outside and it's raining.

You have a road car with internalvolume 2 m3. There is 22°C inside. You come inside completely wet and the water starts to evaporate. The maximum amount of water the 2 m3 of air at 22°C can take is 38 gramms. The rest stays in the form of liquid in the clothes or on the floor.

Now you have a second car with the same internal volume but the inner temperature is 50°C. Again you bring some water inside on your clothes and shoes. The maximum amount of water which can evaporate in 2 m3 of air is now 164 gramms. So your air in the car now contains 4,3x more water.

Where the air hits the cold glass it cools itself and the water condenses because the colder the air is, the lesser amount of water it can take. If you have the same heated windsreen which is capable to heat the screen to let's say 30°C average you have no misting in the road car but you still have big misting problem in the other one (the air at 30°C can take only 37% of water compared to the air at 50°C) and due to the fact that the inner humidity is already 100% the blowers don't work.

So the resume is that you have to either heat the windscreen to higher temperature than what the ambient temperature inside the car is. Or you need to bring less water inside (may not be possible), or you need to lower the humidity (not possible without A/C). Or you need to somehow cool down the temperature inside the car. If you have very high temperature drop between the inside and the outside, heating the screen enough might not be possible, so you need to let as much air from the outside to get in because the air from the outside even if it's wet, will still help because it's much colder but the amount of air you can let in is very limited by the vents. You can't drive on stage with opened windows because it's forbidden. After all you might end in a situation where nothing helps.
Yes, it all makes sense.

Everything but why the teams do not take it in consideration.
Just read an interview with Loeb, where he said, that having a mist problems in a 1 million eur car is nonsense.