White fog/smoke stuff coming out of AC vents when I run the AC.

[mrq]

Hello, all!

I've noticed the past couple times I've had my AC on that some weird white fog/smoke blows out of the vents in my rig. Does anyone have a clue what it could be?

This happened once when it was about 65ºF outside, and just happened the other day when it was 90ºF outside.

Thanks!

 

[flintknapper]

Do you have your A/C set for outside air or recirculate?

 

[mrq]

Do you have your A/C set for outside air or recirculate?

Recirculate. It didn't smell, either. It looked sort of similar to dry ice. But it was a pretty faint amount.

 

[mrq]

Recirculate. It didn't smell, either. It looked sort of similar to dry ice or steam. But it was a pretty faint amount.

 

[mudgudgeon]

was it humid weather?
I've noticed with many different cars when the weather is humid, and you have the AC on a very cold setting, sometimes you will see a few random moments of a little fog of condensation in the cabin as cold air from vents contact moist air in the cab.

if it was humid out, be happy that your AC works really well

 

[IronCladLou]

was it humid weather?
I've noticed with many different cars when the weather is humid, and you have the AC on a very cold setting, sometimes you will see a few random moments of a little fog of condensation in the cabin as cold air from vents contact moist air in the cab.

if it was humid out, be happy that your AC works really well

^^This. If the dew point is very close to the outside temp (or temp in the cabin), the cooler air coming out of your vents lowers the temp of the air enough to cause the water vapor to condense out. Very common and simply indicates that your AC is working fine.

 

[Malleus]

^^This. If the dew point is very close to the outside temp (or temp in the cabin), the cooler air coming out of your vents lowers the temp of the air enough to cause the water vapor to condense out. Very common and simply indicates that your AC is working fine.

x3. This is the physics of AC.

 

[flintknapper]

Completely agree with what the others have posted. Probably just normal.

The reason I asked about your A/C setting however (outside air or recirculate) is that your system can (or might have) picked up a small amount of exhaust gas which would have heated C02 and Water Vapor present. Both will show up readily as a white cloud when they encounter cold temperatures (not unlike that from your exhaust pipe, or even your breath on a winter day).

But since you had the system on recirculate, this seems less likely. I'm going to go with what the others have submitted (small amount of moisture in cab reacting to a very cold and well functioning A/C system).

 

[Hornd]

My Thermodynamics Days are over so here is the chart:

It's condensation and nothing to worry about