hi all,hope you can help
I have a BMW 530d,2002 with automatic airconditioning.if I set the temperature inside the car higher than the outside(without using the aircon,just on the fan),the windscreen fogs up,it helps somewhat if then the aircon is started.Does the aircon need to be used or is there another way to demist or is the ventilation system defective
many thanks
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Hi,
This has a been a problem for me as well in all my recent BMWs. Outside/inside temp differential is, as you say, critical and when in Wales climbing some of the passes in can lead to an almost instant "white out". I don't think that the ventelation system is faulty per se but is a design factor. BMW dealers confirm that this known to happen. I always leave the air con on now and adjust cabin temp through the climate. I think that the demist mode is too "violent" as well....
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Seems to happen in all climate control cars I have had. It is a 'feature' or better 'quirk' of the system. Itis far better to leave the air-con all the time to avoid it. On your car the increased fuel consumption will be almost undetectable.
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Espada III - well if you have a family and need a Lamborghini, what else do you drive?
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"I don't think that the ventelation system is faulty per se but is a design factor."
Is this the same as a 'design fault'?
Anyway, if I understand the original post correctly then when you are trying to heat the car (want the inside warmer than the outside) you get misting up if the aircon is not switched on? This does indeed sound like a fault to me - it sounds like the heater/aircon unit is not draining properly and there is water trapped in there. Have you checked that the drain tube is not blocked?
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fault, quirk, factor - whatever. (sorry semantic/lexicon word interface issue ! get paid by the word see :-))
See my thread when I bought my 530, did the same, not done it through this summer, may be a seasonal thing.
Check my drain tubes on the next serivice.
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thanks guys
how do you check the drain tubes in this car?
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It is all the condensation in the evapourator getting heated up and evapourated into the airstream. The condesation lies there, and when the A/C is off, the pipes are heated under the bonnet by the engine, and hot refrigerant creeps round the system, warming up the damp evapourator and it all ends up on the wondscreen. Best to leave the CC to make it's own mind up when it uses the aircon.
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Sorry for any typos Im very long sited
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nand,
my personal point of view:
i have a 5 series (+ others) and have never had this problem.
in a car fiteed with climate control, as opposed to air-con, there is no point in not having it on constantly. and if you can afford to own and run an exec car, you can afford the tiny extra fuel consumption.
bmw advise you to switch off ac is when the outisde temperature is below 5C.
bmw say, "if the windows fog over immediately the ac is switched off, switch it on again".
however, do make sure your climate control is on auto.
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"if the windows fog over immediately the ac is switched off, switch it on again".
Just found that in the manual as well. They know about it !
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"if the windows fog over immediately the ac is switched off, switch it on again". Just found that in the manual as well. They know about it !
It's almost bound to do that as the moisture on the evaporator is released into the airflow into the car - sometimes the air goes noticeable 'steamy'.
I don't subscribe to the 'leave it on all the time' school of thought - I try to get into the habit of turning the a/c off a few mins from home (if it's been necesary to use it) so that the system dries itself up, and isn't left 'wet' all the time. If I forget, then normally a/c has to be used next day or the car just mists up straight away. My wife's Jazz is quite bad for this - if there's any kind of dampness in the air it's impossible to turn the a/c off, once it's been used.
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Seems that the design of the evaporator, or its housing, is such that it is retaining a lot of moisture. The old Mondeos were bad for this - also leads to smells if the dampness hangs around.
Its true that if you switch the aircon off then, for a few minutes, the incoming air will pick up humidity from the condensate on the evaporator. This should dry off in about 10 mins. If this misting up happens after the car has been left standing for a while then I would say that the condensate is not draining. Check the drain outlet on the firewall.
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Ensure you have the air re-circulation switch/paddle off, this I have found, causes a great deal of condensation on many cars.
Carse
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Ensure you have the air re-circulation switch/paddle off, this I have found, causes a great deal of condensation on many cars. Carse
Good point.
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