i was driving down the highway today bout 60 mph when i noticed an odorless, fine white steam coming out of the vents. I didi have the AC on at the time.This only went on for about 5 min then stopped as i got off the highway. It was kinda humid this moring but there was cool condensation on the car when i got in. Ive heard that lots of humidity and a cold evaporator can cause a fine cool steam, and i hoping thats what this is. My xb is an 06 so the repair will be free if needed.give me some feedback.

 

That sounds like what it is - A/C is basically a giant dehumidifier.
I would just watch it and if it happens again have the dealer look at it.
Just be sure you don't get any mildew smell and that your A/C is nice and cold. If not hat means either your coil is dirty has a blockage in the venting or drain (you should see a small water puddle under car after running A/C for a while) or you have a leak.
More than likely it is just condensation - especially since you had a lot of moisture at the time it occured. Stay cool. . .

 

It's called water vapor. When you blow cold air into warm moist air, you get condensation
or water vapor. You get the same thing when you blow warm moist air into cold air.
That's what makes the white foggy contrail behind high flying jets. Happens to all
my cars here in Hotlantla when the humidity is high.

 

Heheheheh... I used to see that on aircraft in the South Pacific all the time - hot, humid air in the cabin and when the A/C system was first turned on the entire cabin would fill with a dense fog - couldn't see your hand in front of your face - for a few seconds (the ATR42's had MASSIVE A/C systems).

Haven't seen it too many times in a car, but my old Volvo used to do that in Dallas occasionally.

Nothing to worry about. :D

 

the only other explination is that there was too much condensation on the coil and it had to defrost itself, home ones do it all the time, but you dont see it cuse one its in the winter, two its the outdoor unit. i would go for the fact that you had the ac on w/ the fresh air vents on the on position, too much humity in the air caused it, ive had it happen a couple of times on mormings that were really really humid, i woulndt worry about it

 

I used to get the same thing in my 95 Toyota pickup. If I put the AC on in the morning, it doesn't happen right away. I have to leave it running for a while, turn it off for a while and then turn it back on. Then it does it for about minute or so. I thought it was kind of neat.