How to Defog Windows How to Defog Windows

Understanding how to defog your windows can be very important to know when driving on a foggy day. Fogged window can obscure your vision, creating unsafe driving conditions. In a house, foggy windows can raise the amount of humidity inside, leading to mildew and mold. Mold and mildew can be hard to remove and can contribute to many respiratory ailments.

Fog occurs when moisture condenses on glass. For example, if it is cold outside, the heat from your car can make your windows fog up. This can happen on any window, mirror or glass. Knowing how to defog your windows can increase your visibility, lessening your chance of acquiring mold as well as keep you safe while driving.

Defogging Car Windows

Defogging your car windows can be a simple task. Most cars manufactured today come with built-in auto defoggers. If your car is equipped with this feature, it should automatically defog your windows. If you do not have an automatic defogger installed or if it is not working properly, you will need to defog your windows manually. Follow these steps to defog your car windows.

  • Start your vehicle. While your car is running, press the defog button or turn your dial to the defog setting. This is a standard option on most vehicles.
  • Once the defog button is engaged, turn your air conditioner on high. You can also roll down a window as well. The goal is to try to get the inside temperature of your car the same as the outside temperature. 
  • Once the windows have completely been defogged, you can roll up your window and turn your heat on. If it is cold outside, leave your defogger button engaged. This allows heat to continue to blow on the windows, thus keeping them clear.

Defogging Home Windows

Defogging windows in your home can be a little bit trickier than car windows. Unfortunately, homes are usually not equip with a defog button. Therefore, you have to figure out how to bypass this technicality.

  • Keeping a dehumidifiers running during winter months can decrease the amount of humidity that is in your home, thus lessening the chance of your windows fogging up.
  • Clean your windows with an anti-fog solution. Using a solution like or similar to Rain-X can protect your windows from being fogged.
  • Apply plastic to your windows during cold months. Plastic decreases the amount of humidity that can find its way into your home, thus decreasing your chances of getting mold as well as saving you money on your heating bill.
  • Turn on your ceiling fans. If you have ceiling fans installed, turning them on can decrease the amount of humidity inside your home. If you do not have ceiling fans installed, cracking a window can provide you with the same benefits. However, it will also allow valuable heat to escape the house, which in turn could cost you more money on your heating bill.

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