Learn all about how car defrosters, defoggers, and demisters work.
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There are two primary kinds of defrosters. The first type uses a vehicle's heating, ventilation, and air conditioning (HVAC) systems to blow warm, dehumidified air directly onto the foggy or iced-over windshield. The other type of defrosting system defogs and de-ices through a mechanism known as resistive heating.