Windshield fogging with AC ON??? WHY????

[ERIKSKY]

This is so frustrating....

I live in SW Florida and I know its hot here, but come on... this can't be right. When I blow my AC out the front vents, even at the lowest fan speed I get fogging on the windshield directly above the passenger side defrost vent... BUT NOT A DROP ON THE DRIVER SIDE... Please tell me I'm nuts or my service advisor is , this does not seem normal.

I have attached a visual for your enjoyment

[DUBSTER]

I Get The Same Problem Sometimes, Weird!!

[Rambit]

I get that when I restart my car on hot humid days. It only lasts a few seconds and it's on both sides though. Of course I'm driving with my sun roof open and A/C on, so the humidity is inside the car to begin with.

Is this condition present all the time, or just when you restart your car and how long does it last? Have you ever checked the air filter to see if it's wet? It's located on the passenger side. Just a thought.

Rambit

[DUBSTER]

It only happens once in a while. I will check the filter. THANKS!!!!

[EricG]

Could be the filter, not that I would know - however if you are cooling the air to a temp that is 60 degrees or so on a very humid day, it is exiting the vents at a lower temperature than the outside dew point meaning the outside air will immediately condense liquid water on the outer surface of your windshield (that would have a colder surface temperature than the outside dew point) meaning condensation has to happen. Hope that made sense.

Eric

[MrHappy]

Are both sides of the car set to the same/smiliar auto temps? (Just guessing here, that is if you have dual climate control)

[ERIKSKY]

Originally Posted by EricG

Could be the filter, not that I would know - however if you are cooling the air to a temp that is 60 degrees or so on a very humid day, it is exiting the vents at a lower temperature than the outside dew point meaning the outside air will immediately condense liquid water on the outer surface of your windshield (that would have a colder surface temperature than the outside dew point) meaning condensation has to happen. Hope that made sense.

Eric

My main complaint is why is my windshield fogging up only on the passenger side right above the vent when I don't even have those vents on. Shouldn't the AC only becomming out the front vents when that is selected? Almost like its leaking out the defrost vent.

Erik

[bruno]

EricG,
Your explanation seems to match the reason for this condition when I experience it. I can actually see the fog blowing out all the front vents and of course, it almost completely covers the inside (not outside) of the whole windshield. The first time it occurred, I thought something was on fire inside the engine compartment and was being sucked into the venting.

Eriksky,
For me, the condition tends to happen when I'm leaving a geographical area of hot, dry, weather and entering a cooler, balmy, area. Specifically, that exact area is coming down the ridge route of Interstate 5 and switching to the 210 East entering the L.A. Basin of California. It also happened in my Toyota Avalon. I don't think you have anything to worry about unless it becomes something continuous.

bruno

[ERIKSKY]

Originally Posted by bruno

EricG,
Your explanation seems to match the reason for this condition when I experience it. I can actually see the fog blowing out all the front vents and of course, it almost completely covers the inside (not outside) of the whole windshield. The first time it occurred, I thought something was on fire inside the engine compartment and was being sucked into the venting.

Eriksky,
For me, the condition tends to happen when I'm leaving a geographical area of hot, dry, weather and entering a cooler, balmy, area. Specifically, that exact area is coming down the ridge route of Interstate 5 and switching to the 210 East entering the L.A. Basin of California. It also happened in my Toyota Avalon. I don't think you have anything to worry about unless it becomes something continuous.

bruno

Thanks Bruno..

MY condensation is on the outside of the window, I know cuz the wipers will take it off for a second.... And it happens everyday, mostly in the morning.

[bruno]

Originally Posted by ERIKSKY

Thanks Bruno..

MY condensation is on the outside of the window, I know cuz the wipers will take it off for a second.... And it happens everyday, mostly in the morning.

Oops...sorry. I guess mine is a slightly different situation than yours. Normally, I just turn off the A/C and open up the windows to clear out all the white fog.

bruno