Unlike the vehicle’s ventilation system, the rear defroster does not need to blow hot air across the glass. Instead, it heats the window itself, allowing ice and condensation to disappear gradually across the entire surface. This can restore visibility within minutes.
The system is also designed with efficiency in mind. Many vehicles automatically switch the rear defroster off after a certain amount of time. This prevents unnecessary electrical demand and reduces the strain placed on the battery and alternator, especially during extremely cold weather.
