Heater/Defrost Settings & Questions

Beetle, Karmann Ghia, Thing.

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Bookwus
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Heater/Defrost Settings & Questions

Post by Bookwus » Sat Dec 01, 2007 3:42 pm

Hiya All,

First off, the car.......1970 stock Bug. Heating system in reasonably good shape. Fresh air box without the fan.

As you probably know the Pacific Northwest can be wet. With the everpresent moisture in the winter I have a heckuva hard time keeping the windows clear. Any moisture and body heat will fog the windshield pretty quickly. The defrost (Hah! Very funny) only seems to make it worse.

So, what I'm wondering is this.........what settings (see below) have you used to get and keep the windshield clear in wet weather? Yeah, I do carry a towel, but I'm thinking that I just haven't hit on the right combination of the five factors listed below. Any suggestions out there?

Here's what I am using to control fog-up........

1. The two heat levers at the emergency brake pivot. I have the left lever (back seat heat) all the way open (up). The right lever (heat flow) I usually have at halfway. But that goes closed when I'm at a stoplight because it will fog the windshield in a hurry.

2. The heater vents at driver and passenger feet. These I usually run closed for defrost and open for heat. If I run them open for defrost, the windshield fogs immediately. Even when they are closed for defrost, the windshield will start to fog up.

Question......are the heater vents supposed to have some sort of foam insulation on the tongue part in the heater channel? Mine don't and I'm wondering if they are "leaking".

3. Fresh air knobs. These don't seem to make much of a difference one way or the other.

4. Vent wing windows are pretty effective at keeping the windshield clear at the corners. I usually run with them open.

5. Passenger and driver side windows are usually run about a half inch down for air circulation. Seems to help a bit.

Like I've said, I haven't had much success in keeping the windshield clear and the car somewhat warm in wet weather. Suggestions are appreciated.
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hambone
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Post by hambone » Tue Dec 04, 2007 10:28 am

Hang in there Mike, when it's this wet it's really hard to keep a Beetle windshield clear.
What seems to work best: keeping the heat off, opening the vent window and the airflow knobs open. When the car is moving the windshield stays pretty clear. At a stop sign you may have to wipe. I use a small squeegee or paper towels until the moisture level goes down.
For longer trips, use the defroster. Right lever up, left lever down. Make sure the footwell flaps are closed.
This only seems to be a problem when we really get a lot of moisture like the past week. For normal PDX rainy stuff the windshield stays pretty clear.
There must be some sort of anti-fog product out there, I'll let you know if I find anything.
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Amskeptic
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Re: Heater/Defrost Settings & Questions

Post by Amskeptic » Tue Dec 04, 2007 11:25 am

Bookwus wrote:what settings keep the windshield clear in wet weather?
Air-conditioning is very effective at clearing windshields magically quick. The combination of cool and dehumidified air is the key.

We a/c but not A/C VWs have a problem. The cooling fan for the engine takes in ambient humidity. Add road splash water incursion into the heater boxes and you actually have a sauna steam bath with which to defrost the windshield. BIG puddles can give you an instant interior steam-up. For youse Pacific Northwest people, I recommend cold air only for the windshield, and crank up the foot wells for your own comfort. If you have an actual frost or freeze, then you need all defrost (distribution) full heat and you will have to suffer a transition where the windshield is initially painted with fog then finally blessedly "burns through" to a dry clear view.

Late buses are pretty funny with this charming trick. They make four huge grey polka dots of fog on the initially cold windshield that then spreads to the whole glass (you can hear the German engineers (Ha ha ha Hans, ziss vill kill zem kwik, HA!) then finally you get the four huge clear polka dots that allow you to see where you almost could have gone before you crashed.
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hambone
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Post by hambone » Tue Dec 04, 2007 11:44 am

Oddly, I never have trouble with the bus defroster. Always a clear windshield in 5 minutes, rain or snow. I guess a Beetle is closer confines.
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spiffy
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Post by spiffy » Tue Dec 04, 2007 12:35 pm

I had this sauna effect happen to me big time on the way home from the October campout. Took a good 15-20 minutes to burn out the moisture.
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