What is the principle of rear windshield heating?
2 Answers
The principle of rear windshield heating is that the electric heating wire in the glass layer heats the glass, raising its temperature to evaporate fog and water droplets on the surface. Specific process of windshield heating: There is a pattern on the air conditioning mode switch; adjust the air conditioning to the warm air mode, then set the mode switch to the correct position, and the warm air will blow onto the front windshield to achieve the desired effect. Precautions for windshield heating: Before heating, be sure to clear snow from the glass and ensure that the film on the windshield is of high quality and will not melt or catch fire due to heating. If snow is not removed, the glass may crack due to intense thermal expansion and contraction; if a low-quality sunshade film is applied, the heating wire may melt the film, potentially causing a fire.
The principle behind the rear windshield heating actually relies on the resistance wires embedded within the glass. I've seen this design—when you press the rear window defrost button in the car, electric current flows through these fine wires. The resistance causes the wires to heat up, and this heat transfers to the glass surface, quickly melting frost or fog. This process is based on Joule's law, converting electrical energy into thermal energy. I think this device is quite clever, especially convenient in winter, eliminating the need for manual window wiping and providing much clearer visibility when reversing. However, be careful not to turn it on immediately after starting the car; it works more efficiently after the engine is running to prevent excessive battery drain. Also, avoid scrubbing the inner side of the glass too hard during car washes, as broken wires can be troublesome to repair. Overall, it enhances driving safety and is a must-have for driving in rainy or snowy weather.
