Can Outside Humidity Affect Vapour Coming from AC Vents in a Car?

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DaveC426913
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Are there any normal* circumstances under which one might see vapour coming from the AC vents of one's car?

*non-broken-thing


I'm wondering if it had something to do with the outside humidity and the internal temp or something. It was about 28C out, and it's a sunny, muggy day. I had the internal temp at 22. It seemed to happen only when the car was in motion; the moment I pulled over it seemed to stop but if I started back on the road, it would start up again.



On the other hand, when I shut off the car today, the AC made that long, rattly, breathy sigh before going quiet. Has my AC finally given up the ghost?
 
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Oh, my AC on my old SAAB 9000 Turbo did that right before it started spitting little chunks of ice at me. $600 later I pick it back up from the repair shop and about 5 minutes from the place it starts spitting out little ice pellets and dies. I drove it back to the shop, "OH, well, what we did needing fixing, but there must be another problem." Quote to fix 2nd problem $700, because they have to take everything apart again. I told them where they could stick their quote.
 
DaveC426913 said:
Are there any normal* circumstances under which one might see vapour coming from the AC vents of one's car?

*non-broken-thing

Yes, I experienced visible vapour (misty haze) coming from my air vents just a couple months ago. I have an 04 Accord with no problems. I don't remember the circumstances though, but I'm sure weather conditions played a part.
 
Evo said:
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(giggle giggle)
 
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It's completely normal. The AC takes in warm, humid air from outside and chills it. The relative humidity goes up as the air is chilled, and goes over 100%. The water condenses into a fog, and comes out the vent.

- Warren
 
K, thanks. I'm a bit paranoid because I know there is - or was - a tiny leak. It drained once but when I had it repaired they found nothing. I'm driving on eggshells, waiting for it to go kerflooey.