cool weather=foggy windows

What was your climate control setting?

If it was not on AUTO the inside air was not de-humidified.

Quote from: http://www.denso.co.jp/AR-e/1998/TW/climate.html

Warm cabin air has a high moisture content. So, simply recirculating the cabin air would fog up the windows. The new system sends recirculated air out at foot level. Drier fresh air flows near the windows, which prevents moisture from condensing on the glass.

 

Was the fog on the outside or inside? Outside can be easily explained by a significant temperature drop -- warm air holds more moisture and when cooled, fine condensation is formed on windshileds similar to dew.

I have had this happen when climbing a hill and reaching a temperature change with elevation. Instant "fog" on the windows right before my eyes.

Inside would be a different story.

 

LOL! And I was just going to ask if you and your hubby were IN the car when it was parked and the windows fogged.

 

Stop breathing. Problem solved. Galaxee, I've noticed a similar thing now that temps have dropped here in Denver. Anytime there's another adult in the car with me it seems that the winders fog up more easily. If I've just played hockey then everything is steamed up. Can't see the bloody road unless defrost is on. I don't remember my civic suffering from the fogging like the prius has. Maybe there were more leaks and drier air was seeping in. Who knows.

 

I would have to say my Prius is a bit more fog prone than other cars. I recently switched from auto/AC to vent/defrost on the climate control panel (picked up that idea on PC thank you) and it does seem better.

 

I was *trying* to use recirc as much as possible myself recently,
thinking that once I'd warmed that little body of air then I
shouldn't just blow it out the back vents and bring in *more*
cold air. But that definitely fogs things right up, especially
if it's at all wet outside and you have any water on you, or even
if two people get into the car and keep talking, etc. Fresh air,
punctuated occasionally with a touch of the full-defrost button
to clear the windshield faster if needed, is necessary. Oh well,
so much for trying to treat the prius like a superinsulated ski
lodge...
.
_H*

 

We haven't yet established where the windows were fogged -- inside or outside?

She left the car unattended and upon her return found the windows fogged. It seems like most responses are how to avoid interior fogging while driving.

 

I think the Prius is much better sealed then any car I've owned. On recirc we can drive by cow fields and not smell a thing. I leave the car parked with recirc ON, but I'm not sure if this has any effect.

In rain, fog and high humidty driving I use either recirc with the A/C ON or no recirc and A/C off. If you try to recirc with no A/C the windows will fog.

 

In the owners manual it states that when the cabin air filter gets dirty that the windows will fog up real easy. My wife found the entry. We changed the filter and it fixed the problem.

 

Not only is it fog prone, but the outside air vent setting really doesn't bring in very much fresh air.. Even before the winter, on a cooler fall night, driving in the rain (so that the humidity was extremely high) would result in the windows starting to fog up unless the A/C was running.. On my old Corolla, just opening the outside air vent was and turning up the fan was sufficient to deal with this (good thing too as the A/C on that car no longer worked the last 4 years I had it- lost all the refrigerant due to a leak in the hoses from corrosion, although the compressor was still fine)..

I think part of the reason is that the climate control always recycles some amount of interior air and opens and closes dampers automatically, another part is that due to the aerodynamic design, the system simply is not able to pull in a large volume of outside air..

I can say without doubt that this is the single most annoying thing I find about my Prius.. I've said it many times and I'll say it again: I *hate* the automatic climate control system with a passion.. Although it does the right thing for the battery and does keep the passenger compartment comfortable, it also sacrifices fuel economy to do this (by requiring A/C for optimal performance) and this is a decision that I'd rather make myself..