Discussion
N ot sure if we have a problem with the Air Con.
Went out to the car this am and found the windscreen covered in frost/ice. So as usual I used the de-icer and then jumped in the car to demist the inside.
The engine was running, aircon on and the windscreen fast demist (or whatever you call it) pressed in.
However the car windscreen did not demist for 10 minutes.
Also not sure if this is associated, but when the auto button is switched off, the word auto is still displayed on the lcd screen.
Does this sound right or is the Aircon not functioning?
Went out to the car this am and found the windscreen covered in frost/ice. So as usual I used the de-icer and then jumped in the car to demist the inside.
The engine was running, aircon on and the windscreen fast demist (or whatever you call it) pressed in.
However the car windscreen did not demist for 10 minutes.
Also not sure if this is associated, but when the auto button is switched off, the word auto is still displayed on the lcd screen.
Does this sound right or is the Aircon not functioning?
Edited by CatherineJ on Sunday 17th December 12:18
This occasionally happens on my 530 and all the time on my wifes car when the weather is cold.
I find once the heater starts working it clears very quickly.
One thing that does make a difference is which way we park them on the drive !
I.E. - Windscreen facing the house, never happens. Windscreen facing away from the house (more exposed) it often happens !
Go figure ...
I find once the heater starts working it clears very quickly.
One thing that does make a difference is which way we park them on the drive !
I.E. - Windscreen facing the house, never happens. Windscreen facing away from the house (more exposed) it often happens !
Go figure ...
I know there are different opinions about this, but I've always tried not to use the a/c in winter. Some people suggest that it's used for 20 mins once a week to stop the seals drying ou.
If I do have to use it, then I try to remember to turn it off a couple of miles from home so that the system dries out - otherwise when you get in the car in the morning then it just steams up straight away and if it's too cold for the a/c then there's nothing you can do about it.
I do wonder how they go on in colder places? Perhaps it's usually drier there, but people getting into the car with wet coats etc would surely make it mist up.
If I do have to use it, then I try to remember to turn it off a couple of miles from home so that the system dries out - otherwise when you get in the car in the morning then it just steams up straight away and if it's too cold for the a/c then there's nothing you can do about it.
I do wonder how they go on in colder places? Perhaps it's usually drier there, but people getting into the car with wet coats etc would surely make it mist up.
Under the car is the drain from the A/C unit.
Lots of condensation builds up when the warm/moist air comes into conatcat with the cold evaporator.
It the drain gets blocked by road crud, as it may on an off roader the water will just sit in the bottom of the heater box.
When you put the heater on demist you are warmingthe water in the airbox which evaporates into moist air untill it meets your freezing cold screed and condenses again.
In the summer you may have noticed water dripping from under the car. this is normal.
But just chack the drain is clear, I have known these fill up with water so much that the carpets and underfelt has been sodden and the customer has spent a fortune on looking for a water leak!
Ok,the BMW De-mist is generally slow,it all depends on how long the engine takes to warm up..Diesels will take a while (10 mins ish)petrol being quicker.
However most diesels will have the aux heater which will help you out if you time it to come on before a journey and later 1,3,5,7's have PTC(possitive temperature coeficient)aux heater which is a rapid heater that is intergrated into the heater matrix(a matrix is a small radiator inside the dashboard-the fans blow on this and push the warm air through the vents)
The A/C will work to take the moisture out of the air-so when you breath into cold,the steam that comes out is removed from the air.But below 8 deg's(think thats right,may be lower)the system wont work for the obvious reason,you dont want it to snow in the cabin.
The most effective way,well it is at work is to run the engine for 5 mins with the cabin temp set to maximum 32 degs both sides(the reason for this is so that the water valve and pump start pushing the water to the matrix),but dont have the fans or quick demist on.after 5 mins then turn the fans or demist on,there should be a descent amount of heat in the heater matrix at this point to warm the screen.
If the de-mist or fans are on from cold then you have a maximum cooling effect on the heater matrix which is what you dont want-its the same as cooling a engine radiator when its hot.If you have the fan on all the time the engine will never reach its running temperature.
Hopefully that all makes sense--use auxillary to warm the cabin before you go out if you have a diesel and have aux heating fitted.Or try running the vehicle for the first 5 mins with cabin temp set to 32' and with no fans or quick demist on.
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