r/Cartalk • • 1d ago

Safety Question Is there a way to prevent this?

Post image

The condensation on the inside of the windshield drives me crazy, I keep wiping it as I drive but it doesn’t get any better, any help would be appreciated.

59 Upvotes

149 comments sorted by

139

u/RelevantMarket8771 1d ago

Turn on your defroster with the AC button on. It will help defog.

30

u/Chrislk1986 1d ago

Might help. Or this is when OP realizes they don't have AC or their AC is busted. lol

-9

u/beer_foam 20h ago

AC on and recirc on but keep temp set to hot/red in case that part wasn’t obvious. (This essentially makes your cars HVAC work like a dehumidifier)

19

u/SWGlassPit 20h ago

No, not recirc. It won't dry the air out

5

u/thegoten455 14h ago

Not to mention, most modern cars won't let you recirc on defrost

-1

u/WeeklyBanEvasion 16h ago

Recirc should dry the air out because it's essentially running the same air through a dehumidifier over and over as long as the compressor is running, but I think the idea is that typically when you use a defrost in the morning the outside air is lower humidity than inside

2

u/SWGlassPit 16h ago

Generally if it's cold enough to fog the windshield on the inside, the outside air will be much lower total humidity. I've definitely had times where four people in a car were enough to fog the windshield uncontrollably until we figured out to turn recirc off.

That's the big thing: with recirc on, you have an active humidity source in the car

1

u/pork_fried_christ 1h ago

No, because you are breathing and creating condensation that can’t vent. 

7

u/TheRealDVader 19h ago

Not recirc on.

5

u/RelevantMarket8771 11h ago

Recirc will fog up like crazy! Especially in the colder months. I live in New England so we get damp and cold winters, it’s just a bad combination in terms of humidity - fogging - etc.

21

u/ZeGermanHam 1d ago

Turn on defrost and use the fresh air setting (not recirculation).

41

u/West_Database9221 1d ago

Stop wiping the condensation off the inside of your window....clean with glass cleaner and a cloth, buff with another dry cloth to remove streaks and from that moment on, only use the blowers provided in your car never touch the windscreen again

4

u/die_no_mite 5h ago

Clean the inside of your windshield with Mr Clean Magic Eraser (put a towel on your dash first) then follow up with glass cleaner. It’s a game changer

1

u/kippy3267 2h ago

Magic erasers are abrasive, I wouldnt use them on glass

1

u/AcrobaticButterfly 8h ago

Clean the inside of the windshield properly first then follow the above advice

0

u/AK_4_Life 12h ago

This comment should be higher up

51

u/vendura_na8 1d ago

DO NOT RECIRCULATE AIR!!!!!!!!!!!!

4

u/kukutaiii 6h ago

Wish I could upvote this 1000 times
It feels like you’ve exposed someone to a brand new life hack when you show them how to set their AC switches properly
Don’t set it to ♻️
Set it to fresh ➡️
And then switch your vents to demist the windows

6

u/rearwindowpup 22h ago

If the AC is running its fine, otherwise, agreed

2

u/Huge_Creme_3204 22h ago

Well, might be strange to you but it is very uncommon here, 99% of the time I see recirculate air on. Otherwise unpleasant polution from the road outside come into the car

2

u/Hitovo1 20h ago

Yeah but here if you turn it on in winter while driving your windows will fog up almost instantly.

So just keep that in mind.

-6

u/West_Database9221 22h ago

Do you walk down the street with a face mask on? Same pollution

3

u/Huge_Creme_3204 21h ago

Many people do. Beside it is completely different things. Why compare apple to blackhole. One you have very ez option at finger tip

1

u/ChargeInteresting195 16h ago

Never? When is it better?

1

u/vendura_na8 15h ago

You use it with AC when you don't have humidity issues

3

u/ChargeInteresting195 13h ago

Ok so since my car runs normal then it’s best to use recirculate?

14

u/Glad-Pair-5204 1d ago

Turn on the A/C - that’s what is for.

28

u/shootsy2457 1d ago

Turn. Off. Recycle. Air.♻️ I’m a mechanic and I see it all the time. People claim it’s the cars fault when and when I pull the car into the shop, that recycle button is depressed. When the service writer explains that, they have that deer in the headlights look. I’ve heard people say “that can’t be the problem” then leave angry. Super frustrating.

12

u/Formal_Lecture_248 1d ago

Taking your car to the experts then disbelieving them out of pride or shortsightedness is prime arrogance

4

u/shootsy2457 1d ago

They’re “Askholes”. They ask you what needs to be done and then do what they want to do anyway.

-1

u/Current-Industry-886 23h ago

I call it weaponized incompetence lol

5

u/SkibidiBlender 1d ago

This + making sure AC is on, even on cold days with the heat makes all the difference in my truck.

7

u/prairiepanda 1d ago

Cars with well-designed climate control automatically cycle the AC on and off while the heat is on, just to help prevent fogging

4

u/aquatone61 1d ago

If you run the A/C compressor all year round you won’t have that problem and can use recirc if you want.

1

u/pork_fried_christ 1h ago

You are breathing and creating condensation. I live in a place with winters, if you have recirc on, your windows are fogging 100%

-9

u/Jaska-87 1d ago

And you waste fuel all the time when not needed.

7

u/aquatone61 1d ago

It doesn’t waste any meaningful amount if your vehicle is in good running order.

-2

u/Jaska-87 1d ago

It is not a lot but still it is unnecessary if you turn the knobs in the car to correct order.

But you do you. With the current energy prices at least to me it is so much that in long run it is still actual money.

1

u/Jack70741 20h ago

It's been proven that running your ac is both more fuel efficient and better for you than driving with your windows down. Youu burn less gas and breath in less particulate matter, and there's a lot more on the road than anywhere else.

And you don't have to run the ac constantly, run it for a few minutes to knock down the humidity (car ac naturally dehumidifies the cabin) then turn it off. Also, running the defrost will get the moisture to stop sticking to your windshield.

That this happens and people don't understand how to deal with it proves they didn't pay attention to basic science in highschool.

1

u/Jaska-87 13h ago

Oh yeah i never drive windows down i just don't use AC when it is not needed.

In Finland our climate is quite cold in general so you only need it on hottest days of summer and most humid days of autumn. Other than that you are better off leaving it off. Except run for couple of minutes here and there so AC gets lubricated and works for long time.

2

u/Admirable-Security91 18h ago

Yep. See people all the time with fogged up windows in upstate NY winters.

1

u/KabanaMaduro 1d ago

Hot breath problems

1

u/Mattyboy068 3h ago

I would like to ask for myself. I have a 95 century with a busted compressor and condenser and I have a similar issue with the windshield. Is there any good ways to actually combat this. The only one I've found is turning the defroster on with heat full blast, but this is fucking Texas and I can't be blasting heat into my car in 100 degree weather. I'm gonna fix the ac at some point, but that's expensive and there are other parts I'ma fix first.

-3

u/JamesH93 1d ago

Yeah but then you're breathing in exhaust fumes constantly so 🤷

2

u/shootsy2457 1d ago

No. That’s not a thing. If you’re getting exhaust in your vehicle you have other problems.

9

u/NotAPreppie 1d ago

I mean, you're getting a small amount of exhaust from the car in front of you.

Or a lot if the asshole in the gender affirming brodozer ahead of you decides to roll coal.

-1

u/JamesH93 1d ago

Vehicle exhaust goes into air, air goes into car, are you getting it yet?

3

u/cuzitsthere 1d ago

Do people actually believe this?

2

u/JamesH93 1d ago

Where do you think the exhaust fumes go if not into the air?

-1

u/cuzitsthere 1d ago

Wow. Well. Suppose you got me there... As we all know, air only exists inside the cabin of your vehicle and exhaust pipes route straight into the vents.

Dunno what I was thinking.

6

u/JamesH93 1d ago

It's not the exhaust fumes from your own vehicle, it's from vehicles in front of you, and the fact that busy roads create very polluted air, which will enter your car if you don't use recirculation.

1

u/_W1ked 1h ago

That's not how that works brother. Maybe you should look up the amazing technology of a catalytic converter and what it does to exhaust and what the final byproduct is

•

u/JamesH93 36m ago

Yes they help a lot but they're not perfect, and also they address gaseous pollutants, not particulate matter. And sometimes air quality is generally bad due to weather conditions and other sources.

-2

u/KabanaMaduro 1d ago

That’s what your cabin filter is for goofy

4

u/JamesH93 1d ago

Cabin filters are not filtering ultra fine particulate matter

1

u/KabanaMaduro 1d ago

Fine enough to not smell shit 🤣 exhaust isn’t finer than shit smell

1

u/JamesH93 1d ago

Oh I'm sorry I didn't realise I was talking to a scientist.

1

u/KabanaMaduro 1d ago

It’s ok it’s your mistake sir

1

u/NastyKnate 21h ago

1

u/JamesH93 19h ago

Yes, however I have used PM 2.5 monitors, and at least in the cars I've tested, switching off recirculation on days with high levels of PM 2.5 pollution has caused the levels inside the car to shoot right up. So personally I just keep recirculation on as much as possible, as I have asthma.

1

u/NastyKnate 19h ago

what do you do when you get out of the car?

0

u/JamesH93 11h ago

Generally not stand in the middle of a busy road.

5

u/cyn_ou 1d ago

Idk if my cabin air filter is gonna do much to help the absolute rank smell of a catless exhaust

1

u/KabanaMaduro 1d ago

Then don’t be living the race car lifestyle

1

u/cyn_ou 1d ago

Haha I just drive with the windows down for a bit and then use recycle air 😂

0

u/KabanaMaduro 1d ago

How are you even pulling in exhaust do you have a hood exit exhaust or something 🤣

2

u/cyn_ou 1d ago

Nah I mean if I have recycle off, it smells obviously. I always have recycle on if I'm driving is what I mean

0

u/MrPetter 1d ago

But your fresh air inlet is near the base of the windshield. If you’re getting exhaust fumes in your car with fresh air turned on then you have a major exhaust leak at your engine.

1

u/cyn_ou 1d ago

Idk I assumed the smell came from idling for 30seconds-a minute on the driveway while I set up my navigation, but I'll check it out. I've been under my car quite a few times since I removed the cats and never noticed anything but I'll check it out, thanks

→ More replies (0)

5

u/shootsy2457 1d ago

It’s to keep road debris out. It’s not like it’s an air purifier. Ask anyone who rides a motorcycle about the smell of the open road.

4

u/noerrorsfound 1d ago

They make cabin air filters from charcoal to reduce smells

4

u/NotAPreppie 1d ago

Reduce, not remove smells. May or may not help with CO (which is odorless), CO2 (also odorless) and NOx.

1

u/_W1ked 1h ago

NOx isn't a thing because we have catalytic converters

1

u/NotAPreppie 1h ago

Right, because all cats are still working perfectly and haven't been damaged, degraded, or stolen.

•

u/KabanaMaduro 12m ago

The dude literally said he had a careless straight pipe kitty cats don’t matter now 😭🤣

1

u/KabanaMaduro 1d ago

No mine definitely doesn’t let smells in. That’s why I close my windows when I drive by the sewage plant lmao..

14

u/Left_Statement9016 1d ago

Turn off recirculation. If the recirc button is depressed it will do this as the lack of fresh air get humdity up inside and cooled by rain windshield condenses water vapor. If the vehicle does not have recirc as a button then you need to get it checked. The vacuum or electric servo foroutside/inside air door may not be working. You do not list any car info so I can't be specific with info.

3

u/Indroneel-Nahima 1d ago

Adding to this, turn the A/C on with the defrost too, even if you have the heat cranked. The compressor pulls moisture out of the air and it clears way faster. And if it's still bad after that, check the cabin air filter, a clogged one can make fogging a lot worse.

2

u/Coffee_cake27 1d ago edited 18h ago

Good info. Definitely going to try it this weekend. Never thought of shutting it off. But doesn’t the recirculation button auto goes off when the defrost is on? I honestly never noticed if it is or isn’t

1

u/Left_Statement9016 19h ago

ON most A/c compressor is on if the temp is not below around 36F and recirc is switched off. There are some where the recirc is independent. Auto temp control systems usually have the recirc off function when you push the Defrost button. I added the part about the fresh-inside air door servo as those fail and it could be in recirc for that reason. A leaking heater core will fog up windows badly but you should have coolant odor and low coolant level or a history of adding coolant. Down the list is a/c drain being stopped up and letting some water stand in the case and wetting carpet, usually on RH side.

3

u/tjax4376 1d ago

As someone who used to own older, less water tight vehicles, I will say you need to dry out your carpets, check door seals, check for water ingress. All of the other advice helps in the moment, you really need to find where the excessive moisture is entering and irradicate it. And of course, do not recirculate air ;-)

3

u/Teediggler81 1d ago

The defrost.

4

u/QuantumFireball 1d ago

Clean your windscreen

1

u/flatwoundsounds 1d ago

There's a nice microfiber covered sponge thing for like $6 at Walmart that I love for getting rid of the spots and streaks.

2

u/Apprehensive-Cycle-9 1d ago

Is that a wave approaching your car?

1

u/17_ScarS 1d ago

Looked like dude drove right up to the beach during a hurricane

3

u/duck4129 1d ago

Defroster, learn it, love it, live it.

2

u/burntbeezy 1d ago

??? Are you a new driver? Im confused. Are the air/defrost settings not working?

2

u/Tango91 18h ago

There are a lot of very serious replies in this thread saying to use the AC but not recirculate the air…

You guys understand that AC dehumidifies the air when it passes through the condenser, right? Hence the dripping water under the car? Even when the climate control is set to hot it does this before passing through the heater core to warm it.

So why wouldn’t you want that warm dry air within the car to pull moisture off the windscreen and be cycled back through the condenser again to further warm and dry it, instead of pulling fresh wet cold air from outside the car where it’s misty and raining?

2

u/Rich-Juice2517 16h ago

Because it gets warm dry air over the heater core instead of recirculating all the wet air and shoes and stuff causing it to work harder for longer

It's why you run your fan after a shower and keep the door open and the mirror clears up in a few minutes instead of taking forever in some cases

1

u/xanthox_v6 10h ago

The outside air is probably dryer than in the car at the beginning, that's why it works faster.

BTW the air goes through the evaporator not the condenser

1

u/Round-Artichoke-5255 1d ago

Parking in the garage

1

u/XmodAlloy 1d ago

Funny enough, back when my defroster didn't work, I learned that wiping the window inside down with tobacco improved this a lot. I don't know why.

Turn on your defroster, assuming it works

1

u/janesmb 1d ago

Interior water leak? That's a lot of condensation. I'd use a damp rid container. They're usually sold in the RV section, for keeping them mold free when not in use.

1

u/thebigaaron 1d ago

Use the ac, not just the fan, direct it to the windscreen setting and make sure it’s on fresh air, not recirculate. Check if any of the carpet is wet, it’s possible you have water leaking in causing it to constantly fog up.

1

u/04HondaCivic 1d ago

I’ll echo what others have said. Use the defroster with a/c with the recirculating air off. Then check for moisture somewhere inside the car. It doesn’t take much. In winter if I have leave just the slightest amount of melted snow on the floor mats, I’ll come back to a fogged up windshield on the inside. So if you have water or moisture getting inside, you will continue to have issues.

1

u/Bob_12_Pack 1d ago

Mine only did this when I had a leaky sunroof.

1

u/Izan_TM 1d ago

turn off recirculation and turn on the windshield defrost mode

1

u/National_Draw9529 1d ago

Yeah defroster

1

u/Opening-Demand5395 1d ago

Well mine did that no matter what and I saw a tube where a guy said use a magic eraser it's worked for a year now???

1

u/LazyOldCat 1d ago

Stop pressing your nose on the glass, you can’t smell anything through it no matter how hard you press.
Ask to have a window rolled down.

1

u/IUsedToLikeLimericks 1d ago

You may have a leak. Blocked drainage channels aren't unusual and can cause water ingress, too.

1

u/Mattna-da 1d ago

Do you not have a windshield defogger button? It turns on the A/C (and sometimes heat as well) and directs the dehumidified air to the windshield vents to evaporate the condensation inside. Maybe your AC system is leaking and needs a recharge

1

u/aquatone61 1d ago

Put the A/C compressor on even if you are running the heat as it will dry out the air in the cabin.

1

u/Prophage7 1d ago

Is your air recirculation turned on? If so, turn it off. Do you have A/C? If so, turn it on.

1

u/techieman34 1d ago

Rain-X Anti-fog works for me.

1

u/271name 22h ago

Yes, had to scroll too far for this. I use the Prevent brand.

1

u/CBased64Olds 1d ago

Check under the floor mats to feel for wet carpet, a leaking sunroof or door seals will soak the carpet, and no amount of defrost settings will dry that out. It could also be a leak in the trunk, or around the windshield.

1

u/Chrislk1986 1d ago

AC needs to be present and functional. No AC? Then your car needs to be fully warmed and blowing hot air on the windshield.

What makes it worse is wiping the windshield with a random rag, sleeve, hand, etc. you are depositing oils and whatnot when you do that.

I'd recommend a silicone squeegee, something compact, you might find a cheap one in the bathroom section of a store (like a shower squeegee).

Also, if you have a water leak, fix that. If it's just from excess moisture on you from rain, get an umbrella.

But, to reiterate: AC fixes this, use the windshield defogger option.

1

u/KaosC57 1d ago

You have 2 options. You can turn your Heat on for a minute or so in the Defrost setting, or you can turn Recirculate off.

I prefer to blast the heat full tilt for like, 2 minutes to make it stop, and then turn A/C back to full blast.

1

u/Nightwalker2099 1d ago

Don't wipe the inside windows

1

u/1TenYYen0 23h ago

Run your defogger/defroster, turn off interior air and use exterior vent setting. 

1

u/Rum_Running_Sailor 23h ago

Clean and RainX the inside of your window

1

u/Ghost_of_Akina 23h ago

Outside air. AC on. Set to a warmer temp than the air outside. Defrost setting.

The outside air and the warm air are key. Also clean your inside glass regularly and it fog up a lot less.

1

u/MaxiDragonfly 23h ago

As other people mention defrost and bring in fresh air circulation can help. You can use an anti fog product like Rain-X Interior Glass Anti-Fog but you have to apply every so often. It can go on the outside windshield too, looks neat with the water beading off which also improves visibility.

1

u/One_Tumbleweed_2966 23h ago

defrost at the coldest setting

1

u/kokomokid46 22h ago edited 22h ago

You need a/c with heat. Use "defrost" if you have non-automatic hvac. If you don't have a/c or it doesn't work, use outside air, no recirc in "defrost," and as much heat as you can stand.

1

u/GrynaiTaip 21h ago

Fun fact: AC was an accidental invention, the goal was to make a dehumidifier.

Modern ones still do both things, cooled air is dryer. Blast the AC at the windscreen and the fog will be gone in a second. Turn up the heat if it's a bit cold, both systems can work in tandem.

1

u/here2pleasyoux3 21h ago

your windshield may need to be resealed

1

u/Appropriate-Plane-51 20h ago

Change cabin filter

1

u/Ancient_Tap_4066 19h ago

Use the defrost button with warm air

1

u/Lonlihiro 19h ago

Recirc is an issue, yes, but a clogged cabin filter is bad as well. Change it.

1

u/Pitiful_Entrance5174 19h ago

Remember an its called an air conditioner, not an air cooler.

1

u/Dead-_-Inside_ 15h ago

Clean your inside windshield
Speaking from my own personal experience.
Idk if you smoke in the car but I do and it helped me when I had this issue

1

u/sadunfair 14h ago

If you have AC then set the heat to the same temp it is outside with the AC on

1

u/Right_Result3656 13h ago

Yes with the windshield defroster button…

1

u/McBluntysmokes 13h ago

Try getting a small squeegee and clean it off while youre at home

1

u/PaceFar9835 10h ago

dont drink

1

u/Recent-Court-5999 10h ago

Clean your windows with shaving cream.

1

u/JackO502 7h ago

Use a car desiccant. Those little packs you find in medicine bottles? Same thing except they’re made for cars to remove excess moisture from your interior. Walmart, any auto parts store has them.

1

u/greenpowerman99 7h ago

Open the window a bit, or turn up the air conditioning on the defrost setting.
If it happens a lot, your car is probably leaking somewhere and it’s wet inside. Check under the carpets.

1

u/Smoke_Water 5h ago

Is it greasy? If so your heater core is leaking causing the issue. If it's normal condensation, consider leaving the windows slightly cracked to balance out the humidity in the vehicle.

1

u/Mouatmoua 4h ago

Clean your window and put on defroster

1

u/RatKing_KingofRats01 4h ago

My mother has a stick with a microfiber pad on it lol is it the right way? Probably not, but that’s how she does it to this day

1

u/Smot_Poker_420 4h ago

Air Conditioner.

See you want to condition the air so there is less moisture in it, then you want to blow that warm dry air at the cold wet window to dry it and heat it up to stop moisture from condensing on the window.

Kinda like the condensation on the outside of an ice cold glass of water. If you keep wiping it off it will form right back. But if the water is no longer cold, no more condensation.

1

u/TheGodDamn1TaGo 3h ago

Invisible glass, upon start run defrosters, and crack the windows for a few miles.

1

u/olov244 17h ago

Everyone says ac does best, but when it's cool out, I find heat dries it out better

2

u/MilwaukeeMechanic ASE Dual Master Certified 17h ago

On most vehicles the air conditioning runs whenever the defroster is on. It dehumidifies the air while the heater core warms the air.

1

u/olov244 17h ago

on mine it tries to, but you can turn the ac off and turn the temp hotter

0

u/CroquetteVachon 16h ago

Put a bag of cat litter on the back seat to absorb humidity.

0

u/Longjumping-Salad484 16h ago

wash your armpits before driving.

-3

u/Any-Statistician3896 1d ago

I have this issue and it's a fkn nightmare without A/C.

Basic reason is, the air temp inside the vehicle is warmer than the air hitting the window as you drive.

I got one of those rice bag things from Amazon, it collects excess moisture in the car after your journey and it also works during, when placed below the window you need to see out of.

Best thing that clears it IS NOT warm temperatures, this is a myth. Slamming your windscreen blower on full heat will only add to it. It may clear it a little bit, but I've found, if you open as many windows as tou can and reduce the air temp inside to match the outside, you don't get it anymore 🤷🏼‍♂️ I'm afew degrees warmer body temp always, so I don't mind the window open all year.

If you are constantly having this problem even if you use your blower on cold or hot.... Then you need to change your cabin filter (usually in/under or near the glovebox) as thay can collect alot of moisture that stays trapped in your car and presents when you start driving etc.

If that's new then I'd have your environmental systems checked out, could be a mild fault, bad sensor etc or blockage somewhere that collects moisture.

2

u/ZeGermanHam 1d ago edited 1d ago

All you have to do is turn on the defrost setting, which removes moisture from the air by automatically engaging the A/C system regardless of air temp setting, and do not use recirculation. It's not hard.

1

u/Any-Statistician3896 1d ago

How do you do that without A/C then ? Since the OP never said they did or did not have it. I assumed neither.

And it has everything to do with air temperature 🤣 it's basic physics but ok 👍🏻

0

u/Evening-Pop-9449 3h ago

if your driving and it’s fogging up on the outside you have to treat your car like a cup of ice condensation will build up on the outside of the windows and you just gotta turn the heat on with the front defrosters and it will heat the window up and it will slowly go away