Frost on inside windows

[JTP]

Check your fresh air intake and make sure there's no snow/ice in the area. This often causes excess moisture to be drawn into the cabin. Also check the battery area, there might be some water leaking into that tray.

[Quickurt]

On a more serious note, we took a trip last April up into Virginia just in time for a late winter storm.
It took me a couple of times to realize that when I turned the system to recirculate, rather than bringing in outside air, the windows fogged almost immediately and I would have to turn it to AC to clear them enough to drive. The system would be automatically set to outside air and I would have to "correct it"!
The Boxster has such a small volume of air in the passenger compartment, it is very touchy to humidity conditions, especially with two passengers.
Good ideas on what to check from JTP. I would start with the fresh air intake, from my experience.

[Mike_Yi]

Originally Posted by Quickurt

It took me a couple of times to realize that when I turned the system to recirculate, rather than bringing in outside air, the windows fogged almost immediately and I would have to turn it to AC to clear them enough to drive. The system would be automatically set to outside air and I would have to "correct it"!

I'm confused. At the beginning you said that if you set it to recirculate (instead of outside air) it fogged. Then at the end you said that you had to change it to recirculate. Are you saying that recirc or outside air fogs it worse? I'm not sure what mine is set to normally. I think it is pulling outside air.

The manual says that recirculating causes the windows to mist up. Maybe recirc has been on all this time and I didn't notice it.

It seems like outside air would be drier than inside air since it's so damn cold outside. Cold air holds less moisture than warm air. However, if I'm recirculating and air conditioning, it should dry the air more every time that air goes through the system. Outside air would only be dried once, but it starts drier. Hmmm. I might have to experiment with this.

[JTP]

In general, you don't want to set the air intake to recirculate if you want to defrost. You always want fresh air circulating through the cabin to remove the moisture that your body emits plus the snow melting off your shoes adds to the humidity level. If your system can't keep up, cracking the window open alittle helps to remove some moisture from the cabin.

Make sure the cowl under the windshield wipers are clear of snow. The fresh air intake is in that area.

Some cars such as my VW, will disable the recirculate feature if you have it set to defrost. I don't remember what my Boxster does, never had to do it.

[Jaxonalden]

You can always try want I do for my '66 VW bug, use an ice scraper on the inside. I love that car!

[Mike_Yi]

Originally Posted by JFP in PA

Yeah, turn the A/C on.....................

I'm not sure how the newer cars are, but on mine, the A/C is always on by default.

Originally Posted by JTP

Check your fresh air intake and make sure there's no snow/ice in the area. This often causes excess moisture to be drawn into the cabin. Also check the battery area, there might be some water leaking into that tray.

Where are the fresh air intakes? I know the battery tray is dry because I've been messing with the battery so much lately.