The frost forming inside the car is caused by all the water and humidity trapped inside the vehicule (the rain and snow you bring inside with you…). The solution is to get yourself a set of rubber mats but before you put them in, unfold 10 pages or so of newspaper and put them underneath the rubber mats. Then, once a week, when the car is warm after your commute, remove the rubber mats and drain them, then change the newspapers which, by then, will be all wet. Also, when you start driving, crack open the windows for a few minutes so the warm and humid air can get out, otherwise your windows will defrost but the warm and humid air will stay inside the vehicule. Also, if the car is parked inside a garage, leave the windows slightly open. This is what we do here in Quebec (Canada) so if it is good enough for us (considering our winters…) it should work just fine for everyone else in North America.
You didn’t respond to one of the most likely causes: using the recirculate setting on the HVAC.
Just had the same issue. My problem was that the cabin air intake was full of ice (outside of the car, at the bottom of the windshield). The air could not properly circulate and the humidity was trapped.
These are useless for this. Even when new they can only absorb a drop or two of water. And when exposed to room air, they quickly absorb those few drops and become saturated and useless.
I…DO . . in fact know of what I speak . aka; been there - done that.
HENCE ; my advice for school chalk.
But . . Chalk is not the only answer in and of itself. It’s just a desiccant and the last piece of the puzzle.
ALL of the other advice is to be used in total .
One other thing I did with the 06 Escape was . . .
having the windows down some . . - AND - . . running the heater on HIGH to , both, evaporate some and expel that evaporative .
since that first and second winter, 05 & 06 . .
doing all of these things
AND putting in the chalk . . just once.
The interior moisture has . . NEVER . . recurred.
and the chalk is still it its hiding places.
Bought a SILICA FILLED DEHUMIDIFIER BAG on amazon before. It’s not 100% effective but made a difference. My windscreen clears much quicker than it used to.
There are a few products available that were created for exactly that problem. They are formulated to prevent moisture from adhering to the inside of the window. If the moisture can’t stick to the glass, then ice cannot form. Here is a link to a Blog I was reading. I believe it is available in the US quite easily as well.
yeah, that was my first thought too, heater core leaking.
frost on the inside means you have a lot of moisture in your car,the heater core would be the main suspect since it`s located inside your car and has water running through it.