Fog/clouding up on inside of windshield

[mrblotto]

Good day everyone,
A lot of times, especially when it's humid or raining, the inside of my windshield will fog up a lot. Of course, I just wipe it off with a paper towel or such, but it just returns in a minute or two. Surely there must be some product to inhibit/reduce this? Maybe RainX?

Apologies in advance for the 'Dont call me Shirley' crowd.......lol

 

[LTC8K6]

Why doesn't your defroster remove it? A/C not working?

 

[SearchMaster]

There is a RainX anti-fog product but I can't say I was terribly successful with it. It did an okay job on the fog but I must have applied it wrong....left a visible film on the windshield.

 

[mrblotto]

Yes, the AC will remove it, and I could use that on rainy days. I do like to drive with the windows down on nice days, and the fog/film doesn't even go away then.
I was just thinking of a more permanent solution. You know, like how scuba divers spit on the inside of their goggles (blech) to prevent fogging up? I thought there may be a commercial product that does the same thing........perhaps what SearchMaster used.....

 

[LS8]

All RainX products leave a film; it's this film that separates the moisture from the glass and keeps it from "fogging" over.

Basically you can put a dehumidifier in the car (some cars come with these now) or when the windscreen starts to fog up turn on the defroster - after a few seconds the windscreen will be clear again.

 

[Zenmervolt]

Originally posted by: LS8
Basically you can put a dehumidifier in the car (some cars come with these now) or when the windscreen starts to fog up turn on the defroster - after a few seconds the windscreen will be clear again.

Every car with A/C has a dehumidifier. This is why most modern cars will turn on the A/C compressor whenever the "defrost" mode is selected for climate control.

As far as the OP's question goes, aside from trying something like the Rain-X anti-fog or running the defroster even when he has the windows down I don't know of any other ready answers for him.

ZV

 

[mrblotto]

Thank you all for your information/input. *Doffs cap*

 

[LS8]

Originally posted by: Zenmervolt

Originally posted by: LS8
Basically you can put a dehumidifier in the car (some cars come with these now) or when the windscreen starts to fog up turn on the defroster - after a few seconds the windscreen will be clear again.

Every car with A/C has a dehumidifier. This is why most modern cars will turn on the A/C compressor whenever the "defrost" mode is selected for climate control.

As far as the OP's question goes, aside from trying something like the Rain-X anti-fog or running the defroster even when he has the windows down I don't know of any other ready answers for him.

ZV

The dryer in a car's AC system does dehumidify air being circulated through the system but its purpose isn't to dehumidify air already in the cabin - even setting the system to recirculate won't dry the air enough to keep moisture from accumulating on the glass unless the system is set to "defrost". There are cars now coming with dedicated dehumidifiers that work specifically for this purpose.

 

[BW86]

I've used the rain-x anti fog with success

 

[exdeath]

If there is a bluish oily tint to the film on your windshield or if you can faintly smell coolant, you have a pin hole leak in your heater core.

 

[nakedfrog]

Originally posted by: exdeath
If there is a bluish oily tint to the film on your windshield or if you can faintly smell coolant, you have a pin hole leak in your heater core.

And just in case you aren't aware OP, coolant has a sweet smell to it.

 

[LTC8K6]

A properly working defroster system will defog the windshield very quickly even if it is heavily fogged up.

The dryer in a car's AC system does dehumidify air being circulated through the system but its purpose isn't to dehumidify air already in the cabin

IIRC, that dries the refrigerant, not the air.

 

[LTC8K6]

Also, dirty glass fogs up easier and worse, so clean your glass.

 

[Mutilator]

Clean your glass thoroughly with something like Stoners Invisible Glass... that's what I've found to work best over the years.

You'll also want to clean/protect your dashboard with something like 303 Aerospace Protectant... a lot of that crap fogging up your windshield may be from your dashboard outgassing and/or too much previous cleaner (armorall) evaporating and clinging to your windshield. Wipe it on and buff it ALL off - you don't want a shiny residue left behind.

 

[SparkyJJO]

The thing that gets me is when the friggin' OUTSIDE of the windshield fogs up. Sure, a wipe with the wipers will remove most of it, but it doesn't wipe clear and comes right back real fast. A nuisance when it happens.

 

[exdeath]

Originally posted by: LTC8K6
A properly working defroster system will defog the windshield very quickly even if it is heavily fogged up.

The dryer in a car's AC system does dehumidify air being circulated through the system but its purpose isn't to dehumidify air already in the cabin

IIRC, that dries the refrigerant, not the air.

Yes.

AC removes moisture from the air just doing what AC does. It dries and simultaneously cools the air by condensing out the moisture via a cold evaporator to reduce the heat capacity of the air.

In fact the only difference between AC and a dehumidifier is that the dehumidifier is just an AC system that reheats the air back to ambient temperature before discharging it.

 

[Zenmervolt]

Originally posted by: exdeath

Originally posted by: LTC8K6
A properly working defroster system will defog the windshield very quickly even if it is heavily fogged up.

The dryer in a car's AC system does dehumidify air being circulated through the system but its purpose isn't to dehumidify air already in the cabin

IIRC, that dries the refrigerant, not the air.

Yes.

AC removes moisture from the air just doing what AC does. It dries and simultaneously cools the air by condensing out the moisture via a cold evaporator to reduce the heat capacity of the air.

In fact the only difference between AC and a dehumidifier is that the dehumidifier is just an AC system that reheats the air back to ambient temperature before discharging it.

As usual, exdeath nailed it.

ZV

 

[iamwiz82]

If you are anti-AC for defrosting (I've seen this before with people) than you can also set the vent to pull from the outside instead of recirculate.

 

[LTC8K6]

The thing that gets me is when the friggin' OUTSIDE of the windshield fogs up. Sure, a wipe with the wipers will remove most of it, but it doesn't wipe clear and comes right back real fast. A nuisance when it happens.

Warm the windshield up with the defroster and that will usually go away quickly and stay gone.