Climate control setting

[demondali]

What is the best way to set up climate control? I want to set the climate control to 21degrees and leave it. so that no matter what the outside tempterature is it will remain 21degrees....hate having to fiddle around with it all the time.

1) I've been told that i should have a/c switched on all the time? so if the car needs cooling it can do that. Although living in the uk means thats really rare!

2) should the air recirculation be set on? there is two versions of this what is the difference and which one should it be set to?

3) The temperature control eg the red/blue dots...where should this be set to? These seem to have the most control over the temperature of the car. Get this wroung and your either sweating or getting a cold nose! I never manage to get it just right!

Please can someone give me some advise how to set the Climate control for optimal performance!!