When it rains very heavily, it often causes dew on the car window. Dew covering the car window is usually caused by a temperature difference between the air inside the car cabin and the temperature outside. The temperature outside the cabin when it rains is usually cooler than in the cabin and this is what causes dew to appear on the glass.
So the way to get rid of it is to simply turn on the AC, which is the air conditioning system in the car cabin. This method works if the car does not have a defogger or defroster feature, so you have to keep the cabin temperature cooler than the outside temperature.
When it rains heavily, the air temperature outside the car cabin has high humidity. So, the air that enters the car cabin with high humidity conditions, once inside the cabin will turn into water vapor and can be converted into dew on the inside of the car window. The dew that sticks to the glass will become thicker because of the water vapor remaining from breathing from passengers in the car.
Solution to Eliminate Dew Without Having to Get Cold
To eliminate the dew that appears during heavy rain, the car AC must be kept on. This is important because moisture on the car window can interfere with the driver's visibility. However, often the cold blast of the AC also makes the entire cabin cold. What's the best solution?
So that the dew can disappear quickly, the AC temperature doesn't need to be too cold, but make sure the temperature is cooler than the temperature outside. So, for those of you whose car AC settings have a defrost/defogger feature, you can use this feature to get rid of the dew on the windshield.
Defrost vents are usually located at the two ends of the dashboard. The defrost feature is symbolized by an upward ventilation arrow or a steam logo with front writing. So, if you have activated the defrost feature on the car's windshield, we can close some of the AC vents facing the passengers so they don't get cold.
If dew occurs on the rear window of the car, you can use the defogger feature. So, if we turn off the AC and then open the window, it is not always the right solution because there is a large temperature difference between the two rooms and this can make it difficult for the dew to disappear.
Opening Windows If Gutters Are Installed
The quickest and easiest way to remove the condensation that forms on the car window is to open the car window. You can actually open the car window until the dew disappears, provided that a water gutter is installed on the window so that raindrops don't enter the cabin. After the dew disappears, immediately close it again so that you can feel the cold air from the car AC again.
We can use this method when passing through mountains, where the temperature at night and when it rains can be below 18 degrees Celsius. By opening the glass slightly, the aim is to circulate outside air in, so that the outside temperature and the inside temperature are similar.
However, if the rain is too heavy, you can use the recirculation button. When this function is activated, the car will take in air from outside the car and exhale air from inside without changing the temperature. That way, there will be no temperature differences that cause dew to form.
Conclusion
If it suddenly rains and makes the car windows fog up, this condition is definitely dangerous because a driver's visibility can be reduced. It will be even more dangerous if you drive at night and with minimal lighting.
During bad weather during the rainy season, we are required to be extra vigilant and pay attention to driving conditions to stay safe. Dew is the main enemy of drivers because it interferes with vision, so it needs to be removed immediately so that the view is clearer. The presence of air conditioning has proven to be quite helpful in eliminating dew on the glass, and as long as the temperature setting is right, the dew disappears but the cabin doesn't make passengers shiver.
