Using AC to demist windows

Ste7en

Well, we have had AC in three (four if you count our current loan car) now. We rarely use it as the Mrs doesn't like the smell.

Because of this I've still never figured out how to use it to demist windows. Especially during the Winter months.

I'll put it on then switch it off when the windows are demisted, but then they steam up again.

How do you do it?

its_all_Greek

leave it on

IronGiant

A/C doesn't just cool air it dehumidifies it, and it's the latter that is useful when demisting and keeping windows clear.  It tends to get musty if it's not used, so keeping it on will help with that too.

ashenfie

The ac need cleaning if it smells. Most likely bacteria build up.

prezzy

I never turn my air con off summer or winter, annoys me when I get in peoples cars and they have it turned off.

IronGiant

As above...  At the very least you should run it once a month to keep it lubricated and stop the seals drying out.

un1eash

As above if it smells it needs cleaning. Modern cars you can just leave it on, the car will engage/disengage the pump when its needed.

djbsom

As IG said,  AC removes moisture from the air within the car so it's effective in keeping the windows clear with normal use. The systems in use in today's cars run with much improved efficiency than even cars twenty years or so ago although there is a slight deficit in available power from the engine whilst the AC is switched on resulting in slightly poorer economy but IMO not nearly enough to warrant ever switching the AC off. I spend my average day in a car with  stressed and sweaty teenagers in rainy West Wales and I can't remember the last time I switched my AC off.
If you can smell the AC there is something wrong somewhere.
I actually always have the rear drivers side window open half an inch to make sure the car is always fresh and clear as I need clean clear windows more than most.

IronGiant

Try an AC bomb.  I got one from Amazon, but this is the sort of thing :

STP Auto Air-Con Cleaner 150ml

car-man

Don't forget to replace the cabin (pollen) filter before using the aircon bomb.