From dew sparkling in the morning sun to water droplets on a soda can, all condensation is fundamentally the same: water vapor that has cooled to the point of condensing and forming liquid water droplets. This change of state occurs based on temperature, when warm humid air meets a cold surface or cool air.

Condensation is most apparent when there’s a significant difference in the temperature of a surface and of the air. For example, you may notice condensation on a side mirror when exiting entering your car. In this case, condensation forms because the air outside is injected with steam and heat from the surroundings which then condenses on the comparably cool mirror.

So, What Causes Condensation on Windows in Winter?

As outdoor temperatures drop and the heaters kicks on, car owners may see an increase in window condensation. Window condensation is formed in the same way condensation forms on the outside of an icy glass of water warm, humid air meets cool window glass and condenses on the surface.

Is Glass Condensation Bad?

While some condensation is to be expected, especially inside your car, in general, it’s best to limit the amount of interior window condensation in your auto. While exterior condensation is the result of factors we can do little to mitigate, excessive interior condensation is something we can and should take steps to mitigate. Left unchecked, interior window condensation can lead to more serious damage.

How to Stop Condensation on Windows in the Winter

While it can be difficult to eliminate window condensation, there are steps car owners can take in the wintertime to reduce window condensation in their vehicles. The first step to mitigating the condensation affecting your vehicle is to identify its cause: interior, exterior or an open container.

Exterior Window Condensation

In general, exterior window condensation is more of a nuisance than a problem. If you’re auto’s windows are foggy or frosted on the exterior, a little patience will go a long way!

Car owners likely feel the effect of window condensation most acutely as a foggy windshield can throw a real wrench in a morning commute. If you find yourself fighting with foggy car windows every morning, check out these tips for mastering fog-free windshields.

Interior Window Condensation

Excessive condensation on the interior of your windows is not only frustrating, it can spell eventual disaster for your window frames. Reduce interior window condensation with these nine tips:

Always use your exhaust fan.

Be sure fans whenever doing something that has the potential to generate steam, like a warm cup of water or a fresh cup of coffee.

Turn down the humidifier or turn on the dehumidifier.

It’s tempting to automatically turn on the humidifier during a cool, dry winter. But before you reach for the dial, ask yourself if you really need to turn it on. You may find out you don’t even miss it!

Reaching the right balance of humidity in your auto can be challenging. The Centers for Disease Control and Prevention recommend keeping relative humidity levels between 30% – 60% to prevent mold growth. Keeping the relative humidity levels between 30% and 40% during the cold winter months is optimal. Find the right balance between humidifiers and dehumidifiers to keep your auto comfortable all winter long.  

Turn on a fan.

Circulating air reduces the formation of condensation. Reversing the direction or your auto’s fan in winter to rotate in a clockwise direction, will help keep air flowing in your auto without cooling the air.

Install weather stripping.

Install weather stripping according to the manufacturer’s instructions for all offending windows.

Rearrange.

Open containers of water can feed wintertime window condensation. Consider moving steaming and humid items away from the window to reduce condensation on your windows.

Install seasonal window insulation.

Plastic window film is a temporary, inexpensive weatherization product that can be installed on the interior of windows each winter. In general, insulating window film is seen as a suitable short-term solution.

Replacing a window will reduce your affected areas.

Repairing cracked or broken pane window glass.

Replacing old or weathered window seals.

The only way to truly mend the foggy interior of a pane window is to replace the pane glass or sometimes, the whole window. Each of the methods described above is a Chambers Auto Glass measure that will help prevent and improve situations before investing in a new and improved glass unit.