Knowledge Post: Don’t Mythical Car Sunshade

Text / Rowling

As we all know,carSunshieldThe main benefit is to block the sun, so that the light in the active area cannot enter the car, to a certain extent, it can reduce the burning inside the car, and it can also avoid the leatherSeatAnd the instrument panel is damaged by ultraviolet rays. However, some car owners are still skeptical, does the sunshade really have the above-mentioned functions?

In summer, many car owners like to use something called a sunshade, which is placed in front of the windshield of the car. At first glance, it seems that it can really cool down. According to the position, the car sun block can be divided into three types: front block, side block and rear block. Direct sunlight enters the car, the temperature rises, and it also affects the driver's sight. The role of the car sunshade is to block the direct sunlight and make the car more comfortable.

After the sunshade is installed, the temperature inside the car is indeed lower than that without it, but the harmful substances released will also increase, which has a certain impact on health. From the material point of view, the bubble film aluminum foil shade is a kind of plastic products. Aluminum foil has the ability to reflect light, reduce heat radiation and low heat radiation conduction. It has good strength, toughness, and impact resistance, and is acid and alkali resistant. . At present, the automobile industry uses this feature of aluminum foil to make automobile sunshades, which are used for automobile sun protection and heat insulation, and are mainly installed in the car.

The fatal thing is that manufacturers have overlooked the feature that when the sunshade is installed in the car, the sun will penetrate the glass and enter the car, and the aluminum foil will be reflected back into the car by the glass after reflecting the sun. The sunshade and heat insulation layer absorbs part of the heat, and instead blocks the heat in the car, which in turn heats the air in the car. In fact, it is light-proof and not heat-insulated. The parking time is slightly longer and the temperature is also high. Therefore, only those sunshades installed outside the car can achieve no pollution to the car and achieve the effect of sun protection and heat insulation.

There has been such an experiment. Two identical cars were parked in a place exposed to the sun, one with sunshield and one without. After a hot sun exposure at noon, there was no significant difference in the temperature inside the car. Although the sunshade uses the reflection principle to suppress the temperature rise in the car in a short time, after all, the general environment in which it is located has not changed, and the various parts of the car are still thermally conductive. Therefore, after a long period of parking, the temperature inside the car will still rise, and it will not change because of a small sunshade.

Finally, I kindly remind all car owners: When choosing a sunshade, try to choose the one installed outside the car. In addition, parking the car in the shade or in an underground parking lot is also a good way to "sun protection".