i30 Owners Club

GOT PROBLEMS OR ISSUES? => PETROL => Topic started by: Dave470 on December 19, 2019, 15:53:43

Title: Fog on the windscreen when cold
Post by: Dave470 on December 19, 2019, 15:53:43: Hi everyone,

Always when gets cold around 0 degrees, fog on my windows from inside appears. So in cold morning I end up with ice on the windscreen inside the car. This did not happened last winter. I've tried to search for similar topics and the only similar issue I found was blocked A/C drain, but it always caused water on passenger mats. I've checked the car and didn't find anything wet. Did anyone had the same issue? I own Hyundai i30 SE 2016.

Thanks for any help.
Title: Re: Fog on the windscreen when cold
Post by: Shambles on December 19, 2019, 16:43:25: :wttc:

Are your mats wet or is anything damp left in the car overnight?
Title: Re: Fog on the windscreen when cold
Post by: Dave470 on December 19, 2019, 17:14:50: Hi, everything is dry... That's why the only logical explanation seems to be water in ventilation system. Today I've checked the air filter which is located behind glove box on passenger side, filter was a bit dirty but dry. Have no idea where is the moist coming from. It's happening only when is cold that's what I find strange, this morning was 10 degrees and there was no fog.
Title: Re: Fog on the windscreen when cold
Post by: eye30 on December 19, 2019, 17:41:17: I get it and have been since new 7 years.

Depending on wind direction it can be slight, if wind blowing towards rear, or bad, if wind blowing directly onto the front.

So I put it down to colder breeze hitting front screen plus coming into car via the screen vents plus initially warmer inside car than outside therefore internal condinsation .

If I remember I will make sure the screen vent is NOT 'open' and before I turn engine off put vents to feet.

Also, wind direction will decide if the car is on the drive front first or rear first.

Plus
Put circulation to cabin rather than external
Title: Re: Fog on the windscreen when cold
Post by: Dave470 on December 19, 2019, 18:21:09: I didn't think of that 🤔 almost all the time it's on windscreen. I will definitely try it. For some reason I thought it will automatically close when the engine is off....

Thank you 😊
Title: Re: Fog on the windscreen when cold
Post by: sundiz on December 19, 2019, 18:33:11: Get new air filter. Dirty filter causes moisture inside. Clean filter with better air flow helps a bit. But mainly that is just something that happens in low temps. If it is wet you bring moisture inside the car with you (shoes, etc.). Especially here when you get snow inside the car...
Title: Re: Fog on the windscreen when cold
Post by: Dave470 on December 19, 2019, 18:43:10: I will try new filter, and will see what happens. Thai year wasn't snowing yet. Do you think water from shoes is enough to have ice on windows next day?
Title: Re: Fog on the windscreen when cold
Post by: Dave470 on December 19, 2019, 18:44:41: Just to be sure, did u mean cabin air filter?
Title: Re: Fog on the windscreen when cold
Post by: sundiz on December 20, 2019, 03:38:53: Yes, cabin filter. Engine filter has nothing to do with interior air.

When temps get colder moisture will appear. That is just physics. And if you don't drive long distances the condensated water will not get out of your car. Also clean the windscreen (from the inside). Clean glass does not fog up as easily as filthy one.
Title: Re: Fog on the windscreen when cold
Post by: The Gonz on December 20, 2019, 10:11:22: Does your air conditioning have healthy gas? Demisting is not just heating. It works with air con to draw moisture from your cabin air, even when it is cold weather.
Title: Re: Fog on the windscreen when cold
Post by: eye30 on December 20, 2019, 11:22:48: Quote from: The Gonz on December 20, 2019, 10:11:22
Does your air conditioning have healthy gas? Demisting is not just heating. It works with air con to draw moisture from your cabin air, even when it is cold weather.
Had my air con replaced/ regasses few months ago.

At same time I replaced air con filter.

I still get fogging.
Title: Re: Fog on the windscreen when cold
Post by: Dave470 on December 20, 2019, 21:17:51: Quote from: The Gonz on December 20, 2019, 10:11:22
Does your air conditioning have healthy gas? Demisting is not just heating. It works with air con to draw moisture from your cabin air, even when it is cold weather.

I bought that car 1 and half year ago, and didn't service the ar conditioning, so it could be that issue. Anyway I will change the air filter and put the cabin air circulation on when parked, will see what happens when temperature drops to 0.
Title: Re: Fog on the windscreen when cold
Post by: sundiz on December 21, 2019, 11:48:06: Cabin air circulation fogs up the windows. You want dry air from the outside.
Title: Re: Fog on the windscreen when cold
Post by: Dave470 on December 21, 2019, 18:21:40: Quote from: sundiz on December 21, 2019, 11:48:06
Cabin air circulation fogs up the windows. You want dry air from the outside.

This might sound stupid, but is the air from outside dry, when I love by the sea and mostly rainy weather?
Title: Re: Fog on the windscreen when cold
Post by: sundiz on December 21, 2019, 18:50:44: It is basicly same air inside and outside. But you and any other people or animal are breathing and maybe even swetting inside the car. So you don't want to circulate the same air where you breathe and create even more moisture. Fog goes away when moisture gets low or temperature gets high. AC on and fresh air from outside.
Title: Re: Fog on the windscreen when cold
Post by: sundiz on December 21, 2019, 18:53:30: At least my car has this clever button for fogging wind screen. It turns the AC on and changes the air intake to outside.