Frost inside windshield?

clongwor · 12-30-2007, 03:18 PM

I don't remember noticing the last 2 winters, but this year whenever it gets frosty outside, there is also frost inside the windshield. This morning I had to scrape inside the car.

Is this normal? There seems to always be a lot of fog in there too.

davidtm · 12-30-2007, 03:25 PM

I would recommend turning AC "on" in the Climate screen, as that will de-humidify the air inside the car, even when you're not running the defrost mode. Then, there won't be the moisture inside that will condense or freeze on the inside surface of the windows. The AC compressor will not run if the outside temp is too cold, so the hit on mpg won't be so bad.

seasalsa · 12-30-2007, 03:59 PM

Quote:

Originally Posted by clongwor

I don't remember noticing the last 2 winters, but this year whenever it gets frosty outside, there is also frost inside the windshield. This morning I had to scrape inside the car.

Is this normal? There seems to always be a lot of fog in there too.

It is normal if you have AC off. Hit the Auto/AC button on your wheel and it will take care of the frost as stated above.

john1701a · 12-30-2007, 06:39 PM

Using RECIRCULATE allows for moisture build up.

I never do in the during the cold season and have yet to ever see frost inside... here in Minnesota driving a Prius for 8 winters now.
.

clongwor · 12-30-2007, 06:54 PM

Thanks everyone!

That's exactly the problem. I started shutting off the A/C and also started choosing RECIRCULATE in the mistaken belief that it would warm up the car faster than bringing air from the outside.

Duh!

**TonyPSchaefer** · 12-30-2007, 10:48 PM

Quote:

Originally Posted by clongwor

Thanks everyone!

That's exactly the problem. I started shutting off the A/C and also started choosing RECIRCULATE in the mistaken belief that it would warm up the car faster than bringing air from the outside.

Duh!

Well don't come down on yourself too much. The recirculate for warmer air was a good idea and you're right. Unfortunately, you simply failed to take into consideration the water vapor in your breath that is also recirculated.

Live and learn and pass it on.
Trust me, many of the tips most of us pass on were learned the hard way.

jsuh84 · 01-02-2008, 10:52 PM

It was freezing here in Chicago today and I had the same problem. What bothered me was that I just got my '08 Prius this past weekend, and already I couldn't believe a problem like this would occur.

I'll be following the suggestions. Thanks.

smithBYU85 · 01-09-2008, 12:28 PM

I'm in Utah and I have the same problem. I started turning the A/C on to stop it. My problem is that I normally leave the heater off when I'm by myself to help out with my MPG, with a coat and gloves on I stay pretty comfortable.

David Beale · 01-09-2008, 03:44 PM

First, put the climate control system in "auto" mode.
Then just go to the climate screen (press "climate") and select front defrost on the bottom of the screen buttons.

Presto, the windshield is cleared in just 10-20 sec. If you leave it on it's a little noisy, but the windows will not fog up.

qbee42 · 01-09-2008, 03:49 PM

Just to add to the above posts, the climate control system on the Prius is fairly smart, and the A/C compressor is unlike that in most cars. The Prius will only run the compressor when it needs to, even when it is switched on, and the compressor is driven by a variable speed electric motor: If the climate control needs just a little bit of cooling or drying, it will run the compressor at a low power setting. It's not like the all-or-nothing clutch controlled compressors on normal cars.

Tom

12-30-2007, 03:18 PM	#1
clongwor Member Join Date: May 2005 Location: Acushnet, Mass. Posts: 53 My Car: 2005 Prius Package: #6 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Frost inside windshield? I don't remember noticing the last 2 winters, but this year whenever it gets frosty outside, there is also frost inside the windshield. This morning I had to scrape inside the car. Is this normal? There seems to always be a lot of fog in there too.

12-30-2007, 03:25 PM	#2
davidtm Senior Member Join Date: Oct 2007 Location: TJ'ville Posts: 111 My Car: 2008 Prius Package: #6 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Re: Frost inside windshield? I would recommend turning AC "on" in the Climate screen, as that will de-humidify the air inside the car, even when you're not running the defrost mode. Then, there won't be the moisture inside that will condense or freeze on the inside surface of the windows. The AC compressor will not run if the outside temp is too cold, so the hit on mpg won't be so bad.

12-30-2007, 06:39 PM	#4
john1701a Senior Member Join Date: Jan 2004 Location: Minnesota Posts: 2,601 My Car: 2004 Prius Package: Pioneer #3 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 3	Re: Frost inside windshield? Using RECIRCULATE allows for moisture build up. I never do in the during the cold season and have yet to ever see frost inside... here in Minnesota driving a Prius for 8 winters now. .

12-30-2007, 06:54 PM	#5
clongwor Member Join Date: May 2005 Location: Acushnet, Mass. Posts: 53 My Car: 2005 Prius Package: #6 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Re: Frost inside windshield? Thanks everyone! That's exactly the problem. I started shutting off the A/C and also started choosing RECIRCULATE in the mistaken belief that it would warm up the car faster than bringing air from the outside. Duh!

01-02-2008, 10:52 PM	#7
jsuh84 Junior Member Join Date: Sep 2007 Location: Chicago Posts: 17 My Car: 2008 Prius Package: #2 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Re: Frost inside windshield? It was freezing here in Chicago today and I had the same problem. What bothered me was that I just got my '08 Prius this past weekend, and already I couldn't believe a problem like this would occur. I'll be following the suggestions. Thanks.

01-09-2008, 12:28 PM	#8
smithBYU85 Member Join Date: Aug 2007 Location: Provo, Utah Posts: 34 My Car: 2004 Prius Package: #5 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Re: Frost inside windshield? I'm in Utah and I have the same problem. I started turning the A/C on to stop it. My problem is that I normally leave the heater off when I'm by myself to help out with my MPG, with a coat and gloves on I stay pretty comfortable.

01-09-2008, 03:44 PM	#9
David Beale Senior Member Join Date: Jul 2006 Location: Edmonton Alberta Posts: 1,443 My Car: 2007 Prius Package: B Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Re: Frost inside windshield? First, put the climate control system in "auto" mode. Then just go to the climate screen (press "climate") and select front defrost on the bottom of the screen buttons. Presto, the windshield is cleared in just 10-20 sec. If you leave it on it's a little noisy, but the windows will not fog up.

01-09-2008, 03:49 PM	#10
qbee42 Senior Member Join Date: Mar 2006 Location: Northern Michigan Posts: 5,224 My Car: 2006 Prius Package: #7 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 5	Re: Frost inside windshield? Just to add to the above posts, the climate control system on the Prius is fairly smart, and the A/C compressor is unlike that in most cars. The Prius will only run the compressor when it needs to, even when it is switched on, and the compressor is driven by a variable speed electric motor: If the climate control needs just a little bit of cooling or drying, it will run the compressor at a low power setting. It's not like the all-or-nothing clutch controlled compressors on normal cars. Tom