I started my car this morning, and there was a lot of frost on the inside of the windshield. This had to be the result of humid air in contact with the cold windshield, and as the air is dry, the only source of humid air is from my breath. So, when I drive, I fill the interior of my car with warm, humid air, which freezes to the windshield. I've decided that when I get home, I'll roll the windows down and let the fan blow for a few minutes to replace the warm humid air be replaced by cold air. If I am right, it would reduce frost on the inside of my windshield. It can't hurt, I guess. I've seen handheld defrosters which act like a blowdryer to melt the frost on the windshield, do any of them work well? Some of these mornings I waste a lot of time with a frosted windshield.
I'm renting a Prius Liftback right now, and live in The Cities. I'm getting a fair amount of frost on the inside of my windows as well right now due to the -15 temps. Just crank up your heat and a/c while you're driving. It'll clear it out. Will hit your MPGs, but you gotta see.
Do you have the climate control set to recirculate? If so, trying switching it to fresh outside air to continually flush out the humidity. Do you have any significant store of moisture stored in the car? Wet floormats, wet carpet underneath the floormats, damp towel used to dry off the inside glass, sweaty athletic clothing, wet coat or boots, etc? If so, remove and dry them outside the car. Opening the windows to help flush out the humidity several minutes before arriving home has helped in some of my past cars.
Frost? But seriously - there are places in Hawaii where this could be a problem. Higher elevations - Maunakea on the Big Island and even on the slopes of Haleakala. A couple weeks ago we had hail in Kailua and Hawaii Kai. Imagine trying to explain the damage to the car insurance people. "Right!!! and you live where?" This happens once every couple years or so. fuzzy1 is spot on - should run outside air and open the windows (if possible) to get dry air into the car. Mechanic said it's a good idea regardless of temperature to run outside air through the A/C before shutting down as it will usually help to dry out the ventilation system and prevent musty odors...mold?
There's also some discussion about inside-window frost here: First Winter Question | PriusChat It was fun watching snow and ice sublime off my windshield this morning...it looked like smoke
the slope of the windshield increases the problem, but front defrost, high heat and fresh air clear it up in no time. also, try not to sing while you drive, just hum to yourself.
Have you been spying on me? I sing when I drive on the freeway - figure I can't do damage to anyone else when I'm alone in the car. If I don't sing - I often listen to classical music. Not a real big fan but I find that classical makes me drive faster... YMMV
Yup, I've had this issue. The curve makes it not easy to scrape off. I've been rubbing the frost with my glove to make it go away, at least enough to start driving. Opening the windows for a few seconds at the end of your drive or leaving the door open for a few seconds seems to help.
