How To Defrost and Defog a Windshield

As summer’s warm weather fades into chill, brisk fall mornings, citizens around the country can enjoy the break from the sweltering summer sun. However, this seasonal change doesn't just bring a welcome drop in temperature. As morning commutes and school drop-offs get cooler and damper, you’ll notice your once dry and clear windshield becomes riddled with ice and fog.

Not only is this new development a threat to visibility, but it also affects your timely arrivals to work and your safety on the road. Fortunately, Husky Liners knows all the tips and tricks to speed up the defrosting and defogging of your car’s windshield. 

In this feature, we outline the do’s (and don’ts) of defrosting and defogging your vehicle’s windshield, including the proper HVAC settings, whether to vent your windows, and which temperature water to pour over the glass. 

Defrosting Vs. Defogging: What’s the Difference?

While most people conflate the two, defrosting and defogging a windshield are different tasks that require slightly different approaches. Defrosting involves melting away ice from the outside of the glass, while defogging involves drying condensation on the inside of the glass. 

Both methods utilize the HVAC set to defrost with recirculation turned off. However, defrosting requires a hot temperature with the windows closed, while defogging recommends a modest, if not cool temperature, with the windows slightly cracked to dry out the air. Defrosting may also require additional steps, such as manually removing ice from the windshield, whereas defogging relies solely on your vehicle’s built-in equipment. 

How to Defrost a Windshield

Defrosting a windshield isn’t a one-step process. In fact, there are several effective ways to clear ice from the front glass—and some not-so-effective and downright dangerous methods. In this section, we cover Husky Liners’ top-recommended methods for quickly, safely, and effectively defrosting a windshield. 

Use Your Vehicle’s Built-In Defroster

Believe it or not, your car’s defroster is one of the most effective ways to defrost a windshield—surprising, right? This setting on your vehicle’s HVAC controller redirects airflow to vents located at the top of the dashboard, pointed directly at the front glass. 

To defrost the windshield quickly and effectively, use the defroster by turning the heat to high, switching the vent position to defrost, and turning off the recirculation settings. Keep in mind that this method won’t be very effective until your vehicle reaches operating temperature and warm coolant has circulated through the heater core. For this reason, it’s best to use this method when you have plenty of time to warm your vehicle up before embarking on your morning commute. 

Removing Excess Ice with a Scraper

If thick, dense ice is an issue, or if you’re seriously running short on time, manually removing ice is the quickest and most effective way to speed up defrosting. To do so, utilize an automotive ice scraper, a credit card, or even a plastic CD case to scrape away most of the accumulated ice. Once the majority of your windshield is clear, turn on the defroster as instructed. 

Melting Away Excess Ice with Water

When excess ice forms, consider using water to quickly remove it. Using cold water, either in a container or from a garden hose, coat the windshield to melt the ice. Then, use the windshield wipers or a squeegee to remove the water before it resolidifies. 

While you may be tempted to fill up a pitcher with scalding water to melt the ice, resist that urge. Extreme temperature fluctuations can shock the glass, causing the windshield to crack. 

Prevent Ice Formation with a Windshield Cover

As with many things in life, the best way to address an unwanted outcome is to prevent it from happening in the first place. Using a windshield cover can help prevent any moisture from collecting on the windshield and turning into ice. When you remove the cover in the morning, any ice that would have accumulated on the glass sloughs off, leaving a clean, clear windshield behind. 

How to Defog a Windshield

To defog your car’s windshield, turn on your vehicle and set the AC system to the defrost mode. Then, turn off recirculation, set the temperature to cool, and crack the windows. 

While venting the windows in poor weather conditions can introduce more moisture into the interior, installing Husky Liners deflectors and visors, like low-profile Ventvisors, can allow you to crack your windows in rainy, damp conditions while keeping the interior dry and protected.  

Prepare Your Ride for Winter Driving with Husky Liners

Whether you’re battling a frozen windshield or a foggy interior, the key to safe winter driving is preparation, patience, and know-how. By understanding the differences between defrosting and defogging, and following the proper procedures, you can boost visibility and protect your windshield. 

Remember the basics—heat for ice, cool for fog, and avoid drastic temperature changes. Also, don’t forget the value of prevention—employ a windshield cover and Husky Liners Ventvisors to keep the windshield clean, clear, and ready for the road. Check out all our articles for additional winter driving tips, like prep for winter driving and the best winter road trips.