Defogger in Car: Understanding Front and Rear Usage


11 June,2024


11 June,2024

Driving a car on jam-packed roads can be a difficult task, and diverse weather conditions can make it more difficult. During monsoon and winter seasons, fogging can occur in cars. These fogs can be dangerous as they impair visibility. And in extreme weather conditions, windshield frosting can occur. During such weather conditions, a defroster can help improve visibility. The blog will briefly discuss the uses of defoggers and their types.

car defogger

What are Car Defoggers?

A Car Defogger is a device that gives you clear vision while driving, irrespective of the climate.   Imagine taking a hot shower in cold weather. The bathroom mirror fogs up, and you have to wipe the steam droplets to see clearly. This process of droplets settling on the mirror is called condensation, and the same process occurs in your car.


Fogging usually occurs when there’s a temperature difference in the interior and exterior of the car. When warm air comes in contact with a cold surface, fogging occurs, and this is where defoggers play a significant role.


Defoggers can be a great companion during extreme cold weather conditions. The mechanism by which a defogger works is by embedding an electrical heating element within the windshield. As a result, a controlled warmth will be generated, and the condensation of the water droplets will be removed.


The defogger plays a crucial role during the winter season. It helps you drive safely with a clear view of the road.


Types of Car Defoggers

Defoggers are used for both front and rear windows. The types of defoggers are

  • Front Defogger
  • Rear Defogger

Both types of defoggers work differently, but both give the drivers a clear view.

Front defogger

The front windscreen is the main point of view for the driver. If the visibility is impaired due to rain, snow or fog, it can pose a safety threat. So, it is important that the driver’s visibility is clear to have a safe drive.


The front defogger in a car uses the car’s air conditioning, ventilation and heating system to prevent fogging. When the defogger is activated, the car’s air conditioning system regulates hot air through the vents. As the hot air spreads throughout, the temperature increases and causes the water droplets to evaporate.


Rear Defogger

A rear defogger helps the driver watch for vehicles coming from behind or in all directions. Additionally, while changing lanes or reversing, it is important to check the rear window for vehicle movement.


However, both the front and rear defogger are used to ensure clear vision of the road and the movement of the vehicles. The working of the rear defogger varies slightly from that of the front defogger.


The rear defogger works by using an electric heating system. Cars have a thin device called a demister, usually thin lines and almost invisible, which will be placed on the rear windscreen.


When the rear defogger is activated, the electricity passes through the small device and heats it, which helps defog the windscreen.


How to use car defoggers?

It is easy to use a defogger. However, working of a defogger can differ depending on the model of cars but the basic functionality will remain the same. The general outline of how a defogger can be activated is given below.

  • Look for the defogger button on your car’s dashboard.
  • Push the defogger button to activate it. Some cars have an indicator upon activation of the defogger.
  • If you are driving in warm conditions, reduce your car’s temperature for effective removal of front defogging.
  • If you are driving in cold conditions, increase the temperature to remove defogging.
  • Try to adjust the speed of the fan. An increase in the speed of the fan helps in effective defogging.
  • Some defoggers automatically switch off after some time. Still, if there is fog, you have to turn the defogger again to remove it fully.
  • After all the fog is removed, turn off the defogger. This will help save energy and maintain an optimum temperature inside the car.


Tips for effective defogging

Defogging is important for safe and good driving. So it is necessary that you get the best view of the road.

Make sure your windshield is clear without any dirt or grime that may interfere with the functioning of the defogger.

Check the car's vents. If they are blocked by dirt, the defogger will not work at its full capability. Frequent vent cleaning helps with better airflow.

Always have the vents directed to the windows. This will help with better airflow.

While cleaning your car, avoid using abrasive materials, as they can harm the delicate wires and grids. Instead, use a normal cleaner to clean your car. Gently cleansing will help remove the dirt.

If you encounter any issues related to the defogger, it is important to seek professional help and not try to fix it yourself. A properly maintained defogger will help you see the road clearly, which ensures safe driving.


How to prevent fogging?

Fogging can be prevented by using some simple methods.

Silica gel

Silica gel tends to absorb moisture from the air. Silica gel is available in markets you can just place it inside the car, which helps remove humidity.


Foam or shaving cream

Shaving cream or foam can help prevent fog. Try applying a thin layer of shaving cream or foam to the windscreen. This will create a barrier between the surface and the moisture in the air.


Apply some shaving cream in the interior of your windscreen with a dry towel. If you have any residues, wipe it with another dry towel.



Defoggers play a significant in ensuring a safe and a smooth drive for people driving the car. Defoggers can be used during any seasons and one should know how to use it appropriately during different weather conditions.


Defoggers help with a smooth and safe drive, similarly a comprehensive car insurance can help you drive confidently. Additionally, a car can safeguard you during unforeseen conditions like natural or man-made calamities and during accidental damage. Shriram General Insurance provides Car Insurance at affordable premium and you can purchase it online in just a click.



1. Is it necessary to defogger?

Defoggers play a crucial role in driving as it will ensure a safe and smooth driving experience. Defoggers help clear if there is any dust or dirt in the windshield.


2. Does a defogger affect a car’s battery?

The rear defogger uses electrical power to operate. It can have minimal impact on the car’s battery power. However, if used extensively, it can drain the battery.


3. Does an anti-fog spray work?

Yes, car anti-fog sprays can be effective if used according to the manufacturer’s recommendations.

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Save up-to 85% off on your Car Insurance

Save up-to the 85% off on your car Insurance

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