Frost inside windshield?

I don't think I've ever had the climate control on recirculate before. I always leave it on fresh air.

 

And the windows still frost up on the inside? Something is wrong; outside air plus heat should dry the windshield in a jiffy. Lots of people use these cars in Canada, Minnesota, et cetera and don't have this problem.

 

Well, in Canada, when it's nice and cool (-20C ish), frost will deposit on the windshield if there is enough moisture in the car. More than one person in the car, some snow transported into the car when you enter, or more rarely at that temp, high outside humidity.

The solution is easy. Select the climate screen, and press the front defrost button. It will remove the excess moisture from the air ensuring you don't get any more frost on the windshield, and will also remove the frost from the windshield that is already there.

I really don't understand why this topic has so many postings. It's not rocket science. One button solves the problem.

 

hey i do recirculate frequently because i feel that i am sucking less exhaust if sitting in traffic...

i figure, i aint making any, i shouldnt have to breathe any...

 

I need to be a bit more clear. The frost forms after the car sits in the parking lot at work for 8-9 hours. Once I get going and get it cleared off it stays clear.

 

Ah! As the cabin cools the relative humidity rises until water vapor condenses on the windows. It should help to sit and let it run with the defroster going and using external air and a window open and the temperature on max for a minute or so before shutting the car off. Anything to dry out the cabin as much as possible. But then that will reduce fuel economy by some amount... just opening the window for a minute to get rid of as much of the warm air as possible might be enough.

 

This isn't the first car I've had that has done this, but the two cars I've had with this problem have a similar design. I think it is the wedge shape of the windshield as my previous car an Eagle Talon (same as a Mitsubishi Eclipse) would also do this frequently. I think it has something to do with the way the dash sits fairly close to most of the windshield.

The best tips I have to offer as I have dealt with this every year since 1997 have mostly been mentioned prior but...
1. Always kick your boots together before you bring your feet in the car to keep excess snow out of the car.
2. Don't switch the A/C off when on Defrost. (the Talon automatically turned A/C on when in defrost regardless if you tried to turn it off)
3. Make sure your windows aren't cracked while you are parked.
4. It also helps if you try to park where the sun will be facing your windshield for most of the day while you are parked.

 

It may not be rocket science, but just because it doesn't happen to you doesn't mean it doesn't exist. THAT'S why there are a lot of posts. I live in Stuttgart, Germany and also have this problem. Last few days I have had to scrape inside but not outside. That's why I'm on this chat today. I do not recirculate but also do not use the AC. I appreciate that suggestion. My situation is also after the car has been sitting during work. I never get it after the car has been in the garage. Obviously the defrost will clear it eventually. However, I always have the defrost on here. I also wonder if the sun (which we've had a surprisingly lot of lately) shining through the large windows coupled with the weather in the teens contributes to the problem. Thanks again and I'll definitely try the AC suggestion. I normally deselect that.

 

Hi All,

I think I have more understanding of this problem now. And here what is apparently working for me. The Outdoor Air Intake Vent is on the passenger side of the car, just between the hood and windshield. It needs to be cleared of ice and snow. Use a snow clearing brush and hammer the bristles down into the metal grill in the vent to clear those. Then the inside fogging/frosting will be dramatically reduced.

If you do not do this, the car is just recirculating air even when you set the car for outdoor air.

 

I don't actually have frost inside my windshield, but I have noticed fogging on these colder mornings (it was 23F this morning). Today I tried what I have read in this thread. I pressed the Auto AC button and set it for a comfortable temperature, 70. 15 seconds later (I counted!) the windshield was clear. I turned it off, and a few minutes later it fogged up again. So I put it on again. It cleared again, quickly. Wow. I've previously been fiddling with the climate screen, turning off AC, turning on recirc, etc. As someone said earlier here, just press the Auto/AC button on the steering wheel and let it do it's job. I never trusted previous systems to do that (not even my 1999 Lexus RX300). But one good morning today, and now I'm feeling much more ready to trust the Prius AC.

Re: recirc - I usually don't like to inhale the exhaust of the cars ahead of me. But in the Prius, I'm leaving a little more distance between my car and the car in front, and it's less of a problem so far. Actually, since I'm one of the slowest cars on the road by driving at or just above the speed limit, most cars zoom past and I'm not subject to as much exhaust, either Keeping the recirc "open" does tend to keep the windshield clearer.

 

Just remember to stay to the right, please :_>

 

I do stay to the right. Always.

 

There is a product called the Frostshield that you can buy on the web. It is an excellent product. It will eliminate any frost, snow or ice on your windshield. Check it out!