How to Defog a Car Windshield in Seconds

How to Defog a Car Windshield in Seconds

There are some advantages to living in a cold climate, but keeping your car in top condition often isn't one of them. Glass can crack, liquids can freeze and the conditions of the road can be very hazardous. One les dangerous, but very annoying winter car problem is that the windshield can fog up just when you're needing the car to pick someone up or get to work on time. If you need to defog your windshield, it's likely because you didn't prevent your car windows from fogging up in the first place, so keep reading oneHOWTO and we'll show you how to defog your car windshield in seconds. Now you can be where you need to be when you need to be there without worrying about foggy windows.

Why do you need to defog a windshield?

On cold and rainy days it is very common for fogging to occur on your car windows or windshield, which can make you lose visibility on the road and put you and everyone else at risk. The primary cause of the fogging is the temperature and humidity difference between the inside and outside of the vehicle. As the weather outside is colder than the air inside, the relative humidity point is lowered and the warm(er) air inside condenses on the window as it is cooled by the outside air. This is what the fog on the windshield is, it's moisture which has become condensation on the car window.

Your car windshield can fog overnight as you have had the heater on while driving, but when you leave, the warm air remaining in the car turns into condensation and fogs up the windshield and car windows as it cools. This fog is usually even harder to displace as it might freeze in colder temperatures. However, it can also happen while you are driving the car as your warm breath can turn into fog against the cold windshield. Defogging it can sometimes be tricky, so we will show you how to defog your car windshield with the steps below.

Defog with air circulation

To defog the windshield of a car quickly we suggest you let air circulate freely inside the vehicle. This is an effective way to defog your windshield, but it is not necessarily the quickest. However, to defog your car windows in this way, you should lower some windows to let the outside air into the car and have this mix with the heat and humidity of the interior. Hopefully, in a few minutes your car will defog completely thanks to the drop in temperature.

Defog with warm air

If the first trick does not work or you see that the glass has trouble in defogging apply the hot, dry air from the car heating system directly onto the windscreen. If you do not know how to do this you must activate this action by selecting the icon that represents a window and three arrows pointing towards it. Almost all modern road cars will have this, but if they don't or the defog option is not functioning, you can turn on the heating system anyway and it should gradually defog the windshield and car windows. It will take longer to defog the windshield if the heat is not positioned directly toward it, but it will happen eventually.

Defog with cold air

Through the cold air or air conditioning system of the car you can also defog the car windows. Of course, know that if you apply cold air on the glass the moisture will be eliminated more slowly, because cold air is not able to hold as much moisture as warm air. For more information, take a look at our article on how to defog a windshield with AC.

Defog the windshield glass with soap and water

Rubbing the windshield glass with your hands you will remove condensation but only momentarily, so it's not the best way to defog your car. We recommend soaking the windscreen with a mixture of soap and water before starting to circulate. After pass a dry cloth over the windshield to remove the solution. With this action you will stop the car from fogging for some time. Keeping a clean windshield in your car will not only help prevent fogging up, but it will give you an all round better visibility as fog is not the only thing which stops you from seeing the road properly.

Defog the windshield glass with alcohol solution

As the freezing temperature of alcohol is much below that of water, so it is capable of washing away the ice as it won't be chemically affected in the same way. To make the right solution mix 1 part water to 2 parts ethanol or rubbing alcohol and shake together. Put this solution into a spray bottle and spray it on to the windshield and/or car windows. You can do this if you come out to the car in the morning and see there is a lot of frost on the outside this will work wonders. If you are inside the vehicle and see fog on the windscreen, spraying a little bit of the solution will help defog a car windshield in seconds. This is definitely the quickest way to defog the windshield and, as it has such a low freezing temperature, it will not freeze if you leave it in the car like some other products.

Finally, remember that the engine should be at a temperature of about 90 degrees approximately for the windscreen to defog properly and quickly. If your car has air conditioning, defogging the windscreen of the vehicle will be much easier.

If you want to read similar articles to How to Defog a Car Windshield in Seconds, we recommend you visit our Car Maintenance and Repair category.