For anyone with a car, the notion of having to deal with foggy windows while driving is nothing but grief. The problem is that many drivers on the road do not know how to deal with foggy windows, which is why this article even exists. You see driving with foggy windows is nothing but an accident waiting to happen. The decrease in visibility, mixed with the fact that other drivers are unaware of your limitation, could lead to tragic events.
Throughout this article, I aim to explain, somewhat scientifically, why windows fog as well as the solution to the problem and why it works.
One could simply sum almost all of the reason up by saying humidity but it is not that simple. Car windows fog is created when the glass of your windows are colder than the air on either the outside of inside of the vehicle. This is because water condenses on surfaces that are below the dew point of the air besides that surface. To wrap that up, when warm, humid air is next to a cooler surface it will create fog. The issue with this fog is how we can try to prevent it as well as deal with it when the situation arises.
Solving the Problem
When you encounter foggy windows, it is important that you are prepared to act in the appropriate manner. Most vehicles have climate control options that allow you to effectively deal with the issue. You need to be aware of the fact that there are two methods to solving this problem. The solution you choose depends on what the temperature is outside of the vehicle.
The only bit of advice I have that applies to both hot and cold weather, is the application of any product that is designed to prevent fogging. These products are relatively inexpensive and can be found at most local auto shops. The investment you make on these products is well worth it as long as you clean the windows before applying the product.
When Driving in the Cold
When you are driving in the cold and the air inside your vehicle is hotter, causing fog, you have two solutions. If you need to solve the problem quickly then turn the cars defroster on at the coldest setting. This solution levels out the temperatures, which removes the fog but leaves you feeling unpleasant and cold. If you want to solve the problem but you have plenty of time to spare, there is a more pleasant solution.
You can always turn the defroster on high heat and blow that air across the dashboard, which will remove the moisture that has built up.
When Driving in the Heat
When you are driving in warm weather, you will have a different set of solutions to try out. First, try your windshield wipers in case the condensation is forming on the outside of the glass. Then try turning raising the temperature in small increments until you find a temperature that balances out the whole equation. In best-case scenarios, you will find a reasonably cool setting on your AC that also helps heat the car up just enough that the fog problem is solved.
While windshield fog is an annoying problem, it does not have to be an unsolvable one. Following the advice outlined above you can always be one-step ahead of fog. This will increase your safety while driving as well as reduce visual strain.
Eduardo Dieguez is a 1st generation American born Cuban that is currently in pursuit of his AA Degree at Valencia. An avid computer enthusiast, Eduardo spends countless hours tinkering with electronics both new and old. When not working with electronics, Eduardo stays busy writing content for Linear Automotive.