Defog & Defrost Car Windows Fast with these Science-Based Tips:
1) Turn your heater on.
Start your engine, and using the defroster setting, crank the heater up all the way to absorb excess moisture within your vehicle. Remember: Hot air can hold more moisture.
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.
You need fresh air to enter the car as well. Winter air is cold, and as it does not hold much moisture, it is dry. Bringing it into your car ups absorption capacity to more quickly dry the saturated air trapped within.
4) Crack your windows.
This helps exchange the humid air in your car with dryer outside air, speeding up the process.
5) Defrost Windows.
While the above defogging action is taking place, de-frost your windows. This is an entirely separate process that should NEVER (EVER) include hot water. Defrosting quickly takes a minor amount of pre-planning, but saves a snow-capped mountain of headache later. If you can’t stand scraping, put together a simple 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’re stranded.