Come deumidificare il parabrezza

How to defog windshield

As a car owner, you may have noticed that the windshield and windows sometimes mist up.

Why is the windshield fogging up?

Windshield fogging occurs when warm air comes in contact with cold air. The reasons this happens in a car are:

  • Hot air from outside meets cold air from an air-conditioned vehicle.
  • Cold outside air meets warmer air inside the vehicle.

Although fogging occurs on the entire body of the vehicle, it is most noticeable on the windshield and windows and can lead to dangerous driving situations. Most drivers get out and wipe the fogging off, but that’s not permanent and means getting out of the car every time the windshield fogged up.

What is the most effective way to dehumidify your car’s windshield? The best methods

Fogging occurs differently in summer and winter, so the way to dehumidify the windshield will vary depending on the conditions.

How can you dehumidify car windows in summer?

Summer fogging occurs when air at different temperatures meets and deposits on the windshield. In summer there is nothing better than sitting in an air-conditioned car. However, when the hot outside air hits the cold surface of the car windows and windshield, it instantly condenses and forms a layer of mist on the outside of the windshield.

Fog up windshield

How do you remove fogging from car windows in summer?

As a rule, fogging that occurs in summer is much easier to remove, here are a few tips:

Reduce the power of the air conditioner

Although cool air in a car can be very comfortable in the summer, it can be quite dangerous for driving. If you want to reduce condensation on the windshield, try reducing the power of the air conditioner.

When the temperature inside the vehicle rises, the air inside the vehicle begins to adapt to the outside air and fogging quickly stops.

Use wipers

It will fog up outside in the summer and you can easily get rid of it simply by turning on your car’s windshield wipers. Condensation is basically water that forms on the surface of the windshield, and that’s exactly what windshield wipers are designed for. If the windscreen wipers impair visibility due to dirt or insects, activate the wiper fluid (wiper fluid recommendation for summer) and set it to a lower speed to clean the windshield better.

Open the windows

For those who are used to the summer heat and prefer safety over comfort, the fastest and easiest solution for dehumidifying the windshield is to open the window. As soon as you see the windshield and windows fogging up, roll the windows down to the desired height and let the outside air flow into the interior of the vehicle. This keeps the inside of the vehicle at the same temperature as the outside and completely prevents fogging

How do you de-ice the windows in winter?

Unlike in summer, fogging occurs in winter when cold outside air meets the warmer air inside the car. This is the case if condensation occurs inside the vehicle and the windshield is misted up from the inside.

Winter fogging is a lot harder to get rid of, but there are a few ways you can get good visibility while driving.

Circulate air

Key for fog circulation

The air recirculation button, located on the dashboard, is one of the easiest and fastest ways to defrost the windshield in cold temperatures. The button shows a car with an arrow pointing to the inside of the car.

Once activated, this function brings in fresh air from the outside, but does not lower the temperature inside the vehicle. The temperature gradually evens out and the fog that forms on the windshield disappears.

Key for fog circulation

You need to make sure that the “Recirculation mode” is turned off, that’s the button with a car and a circular arrow in it. This function circulates the air inside the vehicle by closing the air ducts at the front.

Lowering the temperature inside the vehicle

This may not be the best option, especially for those trying to stay cool. If the windows are fogged up, you can simply lower the temperature inside the vehicle to adapt it to the outside temperature.

The windshield defroster

Windshield defrost button

Those who really know their cars know that the button with a box and three upward-pointing arrows is known as the defrost button. This button is extremely useful for vehicles that are dealing with colder climates.

Once activated, the defrost button sends air directly to the windshield. This air adapts to the ambient temperature and reduces fogging. Some vehicles are equipped with defrost buttons for the front and rear windows.

How do you prevent your car windows from misting up?

Remove the fog disc

If you want to prevent your windscreens and car windows from misting up in the future, there are a few tips you can implement.

Silica bag

One of the first things you can use is a dehumidifier bag or a couple of them and place them around the dash near the windshield. These bags are filled with silicon beads that absorb moisture from the air. If you can’t find a dehumidifier bag, you can put a handful of silica balls in a sock and place them around your car.

Shaving cream

Shaving foam is another great product that can help prevent fogging. To apply shaving cream, take a handful and use a clean cloth to spread it over the glass. Let the foam sit on the windshield for at least 2 minutes before using another clean, dry cloth and wiping off the residue. It forms a protective layer on the windshield and prevents moisture from building up on the windshield

The best anti-fog products for windshields 2024

Anti-fog products are the best solution to preventing the windshield from fogging without air conditioning.

SONAX anti-fog spray

SONAX anti-fog spray is an anti-fog product for all types of glass, plastic, mirrors and even helmet visors.

Hendlex anti-fog spray

Durable anti-fog product for diving goggles, work goggles, car windscreens or motorcycle helmet shields.

Toulifly Anti Fog anti-fog spray

Compact spray to always take with you in the car, for all types of glass.

Rain-X anti-fog treatment

The specialist company Rain-X has this anti-fog product, which is also effective in high humidity and applies to car windows or at home.

Rain-X 26021 anti-fog treatment

Home remedies for windshield fogging

Home remedies for car window fogging are not as effective as products designed specifically for such an important safety feature as windshield visibility.

As far as rubbing the windshield with a potato, for example, the OCU comes to the conclusion in its tests: “It makes the windows dirty and leaves whitish residue, it is not a good solution”.


The next time you have a fogged windshield or windows, you can use one of these tricks or products to make sure you always have a clean windshield and windows.

Driving with 100% visibility is very important and these tips will help you drive more safely every day or night.

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