Why Do Car Windows Fog up

Why Do Car Windows Fog up

Why Do Car Windows Fog up?

Ever wonder why your car windows keep fogging up? Well. It is mainly because of a process called condensation. Why is that you ask? Fasten your seatbelts for a little chemistry 101. 

Condensation is a process through which matter changes its physical state from gas to liquid. When moisture is present in the air, it starts to accumulate on the cold car windows that are colder than the dew point. 

The condensation of moisture occurs because the window glass is colder than the dew point that is a standard temperature at which dew forms.

So, if you are looking for the factors that lead to your car windows fogging up all the time, then the temperature of the car’s windows and the amount of moisture in the car plays an important role here.

Why Do Car Windows Fog Up on the Outside?

When the moisture and temperature of the outside environment are higher than the inside the car, the condensation starts to happen to lead to the fogging up of the windows. 

It can be due to various reasons; AC is the most common one as it makes the windscreen and windows cold and the temperature almost reaches the dew point.

When this happens, the hot air outside starts to condense upon the outer side of the window and windscreen of the car. This is why usually car windows fog up in summer.

Why Do Car Windows Fog Up on the Inside?

Here, everything reverses, the temperature of the external environment drops low; reach the dew point whereas the inside of the car is warmer, comparatively. 

It isn’t necessary to have a heater on in the car. It can happen only with the presence of two or more people in the car as the body heat warms up the inside of the vehicle(exhaling). When the warm inside air comes in contact with the cold windows and windscreen, it starts to cool down and form vapors on the inner side of the glass; this is why car windows fog up in winter.

How to Stop the Car Window From Fogging Up?

How to Stop Car Windows from Fogging Up in Winter?

Fogging occurs due to the temperature imbalance between the air inside the car and the external environment. Keep the internal temperature as close to the outer temperature as possible.

Here are some tips on how you can balance the temperature and avoid the car windows fogging up while driving:

  • Keep the car windows and windscreen clean to avoid the accumulation of vapors. Remember dirt attracts moisture.
  • Turn on the AC for a couple of minutes to get rid of the fogged-up windows in winter. It balances the temperature as well as removes the moisture from the air.
  • Avoid making the air inside the car moisture by not wearing wet clothes, putting in a wet umbrella, or a beverage. 
  • To get rid of most of the moisture in your car, you can use a dehumidifier or silica to absorb moisture. Check out the latest price of Dehumidifier Moisture Absorber.
  • If the fogging situation gets too worse, open the window for a while to exchange humid areas for dry outside air.

How to Stop Car Windows from Fogging Up in Summer?

Seriously, handling the whole window fogging situation in summer is a lot easier than dealing with one in the winter. The following tips will help you keep the fog off the glass:

  • As soon as the condensation appears, use the windscreen wipers to wipe it all off. 
  • Usually, the car vents are facing the glass, redirect them away from the windows to avoid the steam buildup. 
  • Keep the AC to its lowest setting so you can get rid of the fog by turning on the heater just for a couple of minutes.
  • Another way to prevent the car window from fogging up is to use an anti-fogging spray. Spraying an even layer (or two) of the anti-fogging spray will help you avoid this problem. Check out the latest price of Anti-Fogging Spray.
  • Regardless of the season, keep the circulation off to prevent the windows from fogging up.
  • Cars have a defrosting system that is perfect if you are having a hard time with the fogged-up glass. Use it to keep the glass window warm and fog-free.

Why Do Car Windows Fog Up Inside When Parked?

The main reason for a parked car to have fogged-up windows is the trapped moisture inside. It can happen if the sunroof drain is clogged.

A damaged or missing door vapor barrier, a leaking heater core, or windshield may also cause extra moisture in the vehicle which can fog up the inner side of the windows.

Another common reason behind this problem is wet carpets in the car. They might not feel wet due to the padding that soaks up the moisture. It might make the carpets feel dry but the moisture is still present which leads to fogged up windows at the end of the day.

The trunk can be the trouble maker at times. It can allow water vapors to enter the cabin and create excess moisture inside the car.

In a situation like this, there is a need to exchange the moist air inside the car with the fresh drier air outside. Leave a small slit in the car windows for this purpose.

Why Do Car Windows Fog Up Inside When It Rains?

Why Do Car Windows Fog Up Inside When It Rains

Don’t even try to deny it, car windows fogging up during rain is probably the biggest problem people face especially the ones living in areas with high rainfall. 

Now, this problem occurs due to a very obvious reason. Rain makes the glass windows cold which results in the air inside to become reasonably saturated with vapors.

The water vapors inside usually are a result of breathing and body heat. When the vapors come in contact with the cold glass windows that start to condense up and form little water droplets. 

This condensation makes the glass windows cloudy. If you do not fix it immediately it is going to leave water trains on the glass which are pretty hard to get rid of.

The fastest and easiest way to deal with the foggy-window problem is to turn on the car AC for a while and make the cabin cold so the temperature difference reduces.