Windshield Condensation

[montegoblue]

Hello guys,

Just a simple, maybe trivial question. I currently own a 2008 Carrera S. I am having issues with condensation outside of my windshield (lower areas) when running my AC. I also noticed the same problem on my previous 996 C4S. All my other cars do not do this; I have tried AUTO setting, changing vents, etc. The only solution seems to redirect air completely to my feet but this doesn't seem to work very well when it is warm and muggy. Any input is appreciated.

[rob545]

Hello guys,

Just a simple, maybe trivial question. I currently own a 2008 Carrera S. I am having issues with condensation outside of my windshield (lower areas) when running my AC. I also noticed the same problem on my previous 996 C4S. All my other cars do not do this; I have tried AUTO setting, changing vents, etc. The only solution seems to redirect air completely to my feet but this doesn't seem to work very well when it is warm and muggy. Any input is appreciated.

I have 2006 Carrera and have the exact same issue when running in Auto mode down here in muggy So Fla.

[extrememoto]

mine too, 06 C4S. Maybe apply some RAIN-X on the windshield?

[montegoblue]

Have yet to find a solution -- AUTO mode is out of the question... Just redirecting air with arrows to front only appear to do the trick. This seems to defeat the purpose of AUTO operation ?? Maybe it works well in Stuttgart :P

[Deepsix]

I had the same issue this morning in muggy Texas, as long as the air inside is a lot cooler than that outside this will happen, I find that when the little spoiler thingy pops out the back the condensation seems to go away...lol

I have a 2004 Carrera 2

[wwest]

Amazingly VW has provided a firmware fix for this problem on their version of the Cayenne while Porsche still pretends not a design flaw. I first reported this "flaw" in June of 2001. Subsequently I tried to get it addressed via the local dealer who tore up the service order after I explained what the "job" was to be. In my '01, and previous '99, once the cabin was cooled down to within a few degrees of setpoint the defrost/defog/demist airflow ducts would be opened. I suppose this was to reduce the discomfort of cooling airflow to the face and upper body once the cabin itself was comfortably cooled.

My '01 C4 now has a toggle switch within the console glove box that I use to open the compressor clutch throughout the winter and times that cooling or cool down is not a requirement.

Other than the switch modification my solution to exterior windshield condensation, inadvertent, even DANGEROUS(***), windshield condensation, has been to manually cycle the defrost/defog/demist airflow "on" then OFF. Apparently this action places just that function alone under manual control leaving all others in automatic, including the dash airflow outlet control and the footwell control.

***In late June of '01 we took US delivery of our C4 in Charleston NC at about noon. Hot and humid day, and as is typical to this area of the country sporadic late afternoon showers. Approaching Birmingham Alabama just after dusk, not quite full darkness, I did not at first realize why my night time distance vision was being slightly "eroded". Finally came to the realization that a fine, thin, film of condensation had formed, was continuing to form, on the outside of the windshield. A quick swipe of the wipers cleared up my forward vision INSTANTLY. The C4 has rain detecting wipers but my guess is that the onset of condensation was so slow, and the water "droplets" so tiny, that the rain sensor never triggered.

Be careful out there..

[wwest]

Hello guys,

Just a simple, maybe trivial question. I currently own a 2008 Carrera S. I am having issues with condensation outside of my windshield (lower areas) when running my AC. I also noticed the same problem on my previous 996 C4S. All my other cars do not do this; I have tried AUTO setting, changing vents, etc. The only solution seems to redirect air completely to my feet but this doesn't seem to work very well when it is warm and muggy. Any input is appreciated.

"..other cars do not do this.."

Except the ENTIRE Toyota/Lexus fleet using automatic climate control. Actually almost ANY vehicle, mostly US and asian origin, using NipponDenso, Denso US, automatic climate control designs. Most of these vehicles even have a warning/caution note in the owner manual about this potential. But unlike the idiots at Denso the european models at least take the correct action if the defrost/defog/demist mode is entered manually. INSTANT, massive levels of HOT airflow to the interior surface of the windshield.

[wwest]

Have yet to find a solution -- AUTO mode is out of the question... Just redirecting air with arrows to front only appear to do the trick. This seems to defeat the purpose of AUTO operation ?? Maybe it works well in Stuttgart :P

"..Maybe it works well in Stuttgart..."

No, while we didn't experience any windshield fogging during our tour of the Castles of Europe in the spring of '01 we did take notice of a directly related system operation anomaly. I did bring the effects to the attention of our factory rep when we returned the car for subsequent shipment to the US. Throughout our tour I had noticed that I often, too often, had to "dicker" with the climate control temperature setting in order to maintain the cabin at our comfort level. After returning to the US and inadvertently discovering the condensation problem I examined the operation of the '99 and '01 climate control system more closely.

In doing so I came to the conclusion that what had been happening to us in Europe was that once the cooling airflow began to be distributed, "dispersed", via opening the windshield and footwell outlets the overall cooling effect declined accordingly. Also, glass is NOT a very good insulating material so the cool airflow to the windshield mostly served to cool the windshield itself and thereby also the great "beyond". That resulted, of course, in less cooling capability, overall, to the passenger cabin. So, once the cooling airflow was "dispersed", radiant heating from sunlight would become the more dominant comfort factor and I would then react by lowering the temperature setpoint. 70F vs 72F, soon TOO cool, rise it.

These days when I use the cooling capability of our C4 I set the temperature control to MAX COOL and recirculate and then use the blower speed to "regulate" our comfort level. Often having to add dispersion of the too cool system outlet airflow via opening the footwell vents along with the dash vent. NEVER the defrost/defog/demist outlets, it would take an IDIOT to intentionally do that.

I have learned, the HARD way, that the dehumidification capability, efficiency, of the A/C system is totally a "WILD CARD", more likely to be NON-FUNCTIONAL in my area of the country than otherwise, I NEVER allow the system to be used, activated, except for actual cooling or initial cool down.

[wwest]

I had the same issue this morning in muggy Texas, as long as the air inside is a lot cooler than that outside this will happen, I find that when the little spoiler thingy pops out the back the condensation seems to go away...lol

I have a 2004 Carrera 2

At "those" speeds the windflow is your windshield "wiper" insofar as outside condensation is concerned.