How to Quickly Defog and Defrost Your Car’s Windows

The Crash Course
Defrost icy vehicle windows

Are you ever driving along then the windows in your vehicle fog up freaky fast? It has happened to all of us!

Here are some science-based tips to quickly defog & defrost your windows. No more pulling over to fight for visibility.

  1. Turn your heater on high.
    You want to absorb as much of the excess moisture in the air as possible. The best way to do this is to start your engine, and turn the heat all the way up using the defroster setting.
  2. Press the A/C button.
    This may sound counterintuitive to the whole heater thing, but really what you’re doing is activating a setting on your car’s A/C system that helps dry the air within the cab faster with the help of the coils in your A/C system.
  3. Turn air recirculation off.
    Winter air is cold, and as it does not hold much moisture, it is dry. Bringing it into the car increases absorption capacity & will more quickly dry the saturated air trapped within. 
  4. Crack your windows.
    For the same reason, cracking your windows will help, because it will exchange the humid air in your car with dryer outside air, speeding up the process.

Additionally, you will want to defrost the windows

While the above defogging action is taking place, de-frost your windows. This is an entirely separate process. Reminder this should NEVER include pouring or spraying hot water on your windows. The most common technique is to use a plastic ice scraper, & use moderate pressure to remove the frost or ice from your windows. This will be an easier process after your car has been running for 3-5 minutes & the inside temperature has risen slightly to melt the ice.

If you are interested in defrosting quickly it can be done, it just takes a minor amount of pre-planning, but can save you a lot of time and headaches later. Just mix together a solution of 2/3 cup Isopropyl or rubbing alcohol and 1/3 cup water, pouring the mixture into a spray bottle. This solution will not freeze (rubbing alcohol has a freezing point of 138 degrees below freezing), and can be stored easily in your car, allowing you to easily spray away windshield ice wherever you may be.