Last Updated on August 23, 2022 by
Condensation and Car Windows: An Inevitable Dilemma
Regardless of where you live, keeping the interior temperature comfortable sometimes results in battling foggy windows. If you reside in a cold climate area, you’re probably using the heat setting to stay warm in your car which tends to fog the inside of your windshield. And vice versa, if you’re using your air conditioning (AC) in hot, humid weather, you might have the reverse effect of fogging your windows from the outside. To eliminate or reduce condensation, you will need to adjust the temperature inside the car to closely match the exterior temperature.
Car window fogging is a common issue and people become flustered when trying to prevent windshield condensation when they don’t understand why it even happens in the first place. If you are wondering about it as well, let us help. Here’s everything you need to know about fogging car windows, how to prevent them, and the reasons why they often happen.
Why do our windshields and windows fog up?
There are many reasons and factors why car windows get foggy. The common ones include:
HUMIDITY
Humidity is an accumulation of water in the form of water vapor. When you inhale, then exhale, you’re creating warm, moist air. Your body heat also contributes to the warmth. Windshield fogging is more likely when there is more than one passenger in the car because more heat and moisture are being produced.
TEMPERATURE
Temperature is the movement of molecules, and warm air holds more water than cold air. When water is heated, it turns into gas more quickly than it does a liquid. And, because warm air has more space between each molecule, water molecules may slide into this gap creating fog on your windows and windshield.
CONDENSATION
Moist, warm air coming in contact with your windshield’s colder glass creates condensation inside the vehicle. This generally occurs in the early hours of the morning. This is also why on warm days when your automobile air conditioner is turned on, condensation forms at the windshield base where it meets cold air.
A DIRTY WINDSHIELD
Your windshield collects dirt, trash, and other substances and moisture in the air is more likely to adhere to a filthy surface than a clean one. As a result, a dirty car windshield may result in a foggy windshield outside your vehicle.
Recommended Products for Preventing Car Window Condensation
In conjunction with the steps above, here are a couple of highly-rated products & tools that our automotive community recommends to battle foggy windows:
Rain-X Glass Treatment & Anti-Fog Combo – best for exterior condensation
Rain-X 630046 Interior Glass Anti-Fog – 12 fl. oz. – best for interior condensation
SHINE ARMOR Anti Fog Hero with Microfiber Cloth Windshield & Glasses Spray Cleaner
What causes condensation on inside of car windows?
Condensation inside the vehicle is a problem that affects all cars. Condensation occurs when wet warm air becomes contact with a cold surface, such as your car’s windshield. When hot air collides with cold air, humidity in the warm air condenses on the cold surface. This moisture appears as hundreds of tiny water droplets on a car windscreen, looking similar to foggy windows. Condensation within the vehicle might be caused by one or more of the following factors:
- Wet clothes, shoes, and/or pets – Water on these objects will gradually evaporate into the cabin air or, if significantly drenched, cause the seats and carpet to get wet
- Breathe – When you or your pet exhales, a massive volume of water vapor is discharged into the air
- There is a water leak
- There is no fresh air movement
How to stop or prevent condensation in your car
First and foremost, wipe down your windows both inside and out. Because moisture clings to dirt particles, a dirty window is a breeding ground for condensation. Use a windshield cleaning solution and a clean microfiber towel to shine the windows. In an emergency, some newspaper will suffice.
Second, turn on the Defrost button. It’s the most straightforward approach to keep the vehicle dry. It will turn on both the heating and cooling systems. The air conditioner will remove moisture in the air, while the heating system keeps the interior suitably heated.
Third, create a Ventilation Route. Leave the windows open (partially is fine) when driving if it’s a bright day or the sun is up. It will keep the interior warm while also allowing moisture to escape.
Lastly, throw away all wet items from the car. One of the primary causes of condensation inside the car is storing damp objects such as boots, clothing, floor rugs, and more. Because you know what causes foggy glass surfaces, you should eliminate all sources of moisture to keep the windows clear.
How to stop your windows and windshield from fogging up in winter:
When the temperature outside of your automobile is lower than the temperature inside the car, there are no one-size-fits-all guidelines for how to cure a foggy windshield. Though, there are a few steps you can take in the circumstances of needing to remove windshield fog, including:
- Increase the temperature – Set your car’s heater to the highest setting. Because hot air contains more moisture than cold air, turning up the heat will aid in collecting moisture that adds to a foggy windshield.
- Turn on the air conditioning – Turn off your car’s heating before turning on the air conditioner. This aids in removing moisture in the air as it passes over the air conditioner’s cooling coils.
- Reduce air recirculation – Turn off your vehicle’s recirculation system. This permits the entry of cold, dry air into your car.
- Roll down the windows – For a few minutes, leave the windows open. This aids in the removal of fog from your windshield by combining humid air inside your vehicle with the cold, dry air outside.
How to stop your windows and windshield from fogging up in summer
When you have a foggy windshield in warm weather, it means that the moisture level and temperature outside your vehicle are higher than the inside. To prevent a foggy window in warm weather, raise the moisture level and temperature inside your vehicle. Here’s what you should do in this situation:
- Turn on the windshield wipers – To clear condensation from the windshield, utilize your car’s windscreen wipers.
- Turn off the air conditioner – Reduce the temperature of your car’s air conditioner or turn it off completely. This will raise the temperature of your car without overheating .
- Avoid recirculation of air – Turn off your vehicle’s air recirculation system. This assists in guaranteeing that the moisture level and temperature inside your automobile will quickly match the outside.
Summary on Window Condensation
Drivers must handle various situations before they cause concern, such as driving in snow or controlling their vehicle on slipper roads. Even minor problems can result in hazardous situations. A car with foggy windows may not appear to be a significant issue, but it can quickly become life-threatening. You will have to deal with window condensation no matter where you reside. Knowing what to do in this situation will make you safer driver and we hope the advice above will come to mind the next time you deal with foggy windows.