When you hit this button:

Most people are not aware that their car’s defroster is tied into the air conditioning system. While that means it can get quite warm and very cold, it also means something else. If you’ve ever had to use a humidifier in your home during the winter because your furnace was removing too much moisture from the air (itchy skin anyone), then you’re already familiar with what’s going on here.

Your air conditioner (whether it’s set to cold or hot) condenses the moisture out of the air into water. This condensation that is captured is vented through a drain hose that runs from behind your glove box out the bottom of the car. The system then pumps dry air into the car. When you turn on the defroster, your vehicle is actually turning on the a/c system which enables it to pump dry air up toward the windshield. This helps to evaporate the moisture far more quickly than it would without the a/c being on.

The right temperature

Sometimes, different temperatures are needed. For example, you may notice that cold air works better during the summer and warm air works better during the winter. This is simply due to the outside ambient temperature. Your defroster (in addition to drying the humidity from the air) is also equalizing the temperature of the windshield and the interior air to some extent.

Unfortunately, this also means that if your air conditioner isn’t working properly, your front defroster won’t work right either. It may either only slightly clear the moisture from the glass, or it may not work very well at all. Generally, this is caused by low refrigerant levels in the air conditioner system or some other system fault.

Talk to your Service Advisor at Auto Care Plus and have them get your system in tip top shape for the coming winter season!