Inside of front windshield frosted over.

[Justin33]

Make sure you don't have your air set to recirculate. That is the single biggest cause of frosted windows. Last week it was -40 here. Saw a ton of vehicles with heavily frosted windows inside. All being driven by immigrants. They think recirc heats faster than heating outside air. All it does is load damp air from inside and freeze it to the windows inside. If you are on full defrost, it does it even faster.

If the cabin air is warmer it should heat up faster though right?

 

[Dean2]

If the cabin air is warmer it should heat up faster though right?

That is what everyone who uses recirc knows too. It is why you see all the immigrants riding around with completely fogged windows. While technically true that heating inside warmer air warms things faster, the offsetting fogging of the interior of the windows is a much bigger issue than it taking a bit longer to warm up inside.

 

[Mister Luck]

Make sure you don't have your air set to recirculate. That is the single biggest cause of frosted windows. Last week it was -40 here. Saw a ton of vehicles with heavily frosted windows inside. All being driven by immigrants. They think recirc heats faster than heating outside air. All it does is load damp air from inside and freeze it to the windows inside. If you are on full defrost, it does it even faster.

HVAC is supposed to remove moisture from the air in both modes heating and cooling as long as your HVAC is turned on and working properly when you park your recirculating vent should keep the outside fresh moist air out
The recirculating vent does not stay closed as some might expect and it opens independently to keep mold from building internally .

When you park your vehicle you should hear the vents cycle and close but if you do not the recirculating vent may be stuck or it’s module broken.

 

[Dean2]

Yes, we have always run the AC on heat or defrost to remove moisture. The newer vehicles now do that automatically particularly if you engage defrost setting. All I can tell you is even the new vehicles clear the windows WAY, WAY better if you use outside air. At minus 20 to minus 60 there is very little actual moisture in the outside air. Remember, the humidity you see on the weather is relative humidity, which means it is temp adjusted. 50 percent relative humidity at 40F has way more actual moisture than 50 percent relative at -40F. Between your breath, moisture on floor matts, snow tracked in etc there is far more moisture inside the car than outside and the warmer air suspends a lot more moisture too.

Absolute humidity is the amount of water vapour present in a given mass of air at a particular time and temperature, while relative humidity is the ratio of the amount of water vapour present in the atmosphere to the maximum amount of water vapour the air can hold.​

And just for clarity, cold air has a lower potential maximum water capacity than warm air.

Hot air expands, and rises; cooled air contracts – gets denser – and sinks; and the ability of the air to hold water depends on its temperature. A given volume of air at 20°C (68°F) can hold twice the amount of water vapor than at 10°C (50°F). The relationship of how much water a given mass of air actually holds compared to the amount it can hold is its relative humidity. When air holds as much water vapor as it can for a given temperature (100% relative humidity), it is said to be saturated. If saturated air is warmed, it can hold more water (relative humidity drops), which is why warm air is used to dry objects--it absorbs moisture. On the other hand, cooling saturated air (said to be at its dew point) forces water out (condensation). This is why a container of a cold beverage sweats: it cools the air next to it and moisture from the air condenses on the outside of the can.

 

[Justin33]

That is what everyone who uses recirc knows too. It is why you see all the immigrants riding around with completely fogged windows. While technically true that heating inside warmer air warms things faster, the offsetting fogging of the interior of the windows is a much bigger issue than it taking a bit longer to warm up inside.

Very true so what should I do when it rains and it wasn’t to fog the windows? Ac on seemed to help with cold air blowing versus hot.

 

[Mister Luck]

Yes, we have always run the AC on heat or defrost to remove moisture. The newer vehicles now do that automatically particularly if you engage defrost setting. All I can tell you is even the new vehicles clear the windows WAY, WAY better if you use outside air. At minus 20 to minus 60 there is very little actual moisture in the outside air. Remember, the humidity you see on the weather is relative humidity, which means it is temp adjusted. 50 percent relative humidity at 40F has way more actual moisture than 50 percent relative at -40F. Between your breath, moisture on floor matts, snow tracked in etc there is far more moisture inside the car than outside and the warmer air suspends a lot more moisture too.

Absolute humidity is the amount of water vapour present in a given mass of air at a particular time and temperature, while relative humidity is the ratio of the amount of water vapour present in the atmosphere to the maximum amount of water vapour the air can hold.​

And just for clarity, cold air has a lower potential maximum water capacity than warm air.

Hot air expands, and rises; cooled air contracts – gets denser – and sinks; and the ability of the air to hold water depends on its temperature. A given volume of air at 20°C (68°F) can hold twice the amount of water vapor than at 10°C (50°F). The relationship of how much water a given mass of air actually holds compared to the amount it can hold is its relative humidity. When air holds as much water vapor as it can for a given temperature (100% relative humidity), it is said to be saturated. If saturated air is warmed, it can hold more water (relative humidity drops), which is why warm air is used to dry objects--it absorbs moisture. On the other hand, cooling saturated air (said to be at its dew point) forces water out (condensation). This is why a container of a cold beverage sweats: it cools the air next to it and moisture from the air condenses on the outside of the can.

Defrost vent setting only uses fresh air of course if you sweat a lot and breath heavily your windows are naturally going to fog up and you have the risk of being detained in a public place.

However if you park your truck overnight check to see if the vents automatically close or it’s like leaving your window open

There are window covers for snow and ice you can place on the outside of your windshield, they are attached by tethers that close inside the front doors and help to also insulate the inside of the windshield

Isoprene alcohol on a towel wiped inside the windscreen help to remove frost build up but is flammable probably best to use with the door open.

 

[truck2569]

Good morning,

I live in the Pacific Northwest where the last couple days have been in the teens to the single digits for a low temperature… I went out to my truck and noticed frost on the inside of the windshield… I drive the truck sometimes 2-3 times a week and sometimes it sits 2-3 weeks before driving it… Called the dealer, and they say this is common for this time of year, especially when it gets as cold as it’s been… They also said there’s nothing they can do… I have owned a lot of vehicles in the past, and I feel like I’ve never had this issue before… Is anyone else having this issue? Is this a common issue? And if so, is there a fix? My truck is a 2022 Ram 1500 Limited… Thanks

The only way to solve this issue is put a littler heater in then vehicle. Itis condensation on the inside of the vehicle that is causing it from the weather change. That is what I had to do if I wasn't going to use my vehicle.

 

[GTyankee]

I am picturing someone putting a heater in a car, after the car has been parked all night outside in freezing weather.
If it happens to have a short crack from a window chip, it may be much longer after the heat is turned on.

Now that Winter is basically over, i found something that would be useful in a basic Ram
so you can have a warm butt & back

MEELEEDUN

1

www.amazon.com

 

[Dean2]

Block Heater effectiveness 5.7

-41c here last week and never plugged my 20 in. Wind makes no difference on how cold the engine gets. I much prefer to pump cold oil into a cold cylinder rather than cold oil/ warm(dryer) cylinder. Not me,as the oil will warm up that much faster on a warm block.You're not pumping oil into...

www.ramforum.com

This thread should help.