Heated mirrors is a system for heating exterior rear-view mirrors, which allows you to get rid of fogging windows, excessive concentration of moisture on the surface, and the formation of ice. Thanks to heating, visibility can be improved, which allows you to have a positive impact on car safety.
Heated mirrors: application and principle of operation
The installation of such a function is justified mainly in countries with harsh winters and long off-season periods. Mirrors from the outside fog up with significant changes in humidity, in a blizzard, frost and rainy weather. If the country has a tropical climate, then thanks to heating, you can get rid of the need for manual wiping in the rain. It turns out that the use of a heating system is justified under any operating conditions and in any climate. Heated mirrors are usually classified as systems for improving the comfort of a car.
The action is based on evaporation by means of a heating element of excess moisture. The formed ice and adhering snow are melted with the help of a heating element. And under the influence of high temperature, the moisture formed as a result of heating evaporates. The operating temperature of the heater is approximately 50 degrees Celsius. This temperature is quite enough to prevent freezing of mirrors at an external temperature of -50 degrees Celsius, keeping the surface of the mirrors clean. The heating elements are powered from the vehicle’s on-board network using a switch, which is usually interlocked with a rear window heating switch. Heating can be switched on automatically by commands from the on-board computer if the outside temperature has dropped below zero or if the rain sensor that triggers the wipers has tripped.
By type of device, mirror heating is usually divided into three types. The first type includes mirrors having a wire heating element. It is installed behind the reflective layer, isolated from it with a layer of glue or with a sticky polymer tape. The coils of the spiral are usually also insulated with the help of the lining and have a small air gap that does not allow the heated metal to expand, while the design of the mirrors is not subject to destruction. This type has the simplest design. The second type includes mirrors with heating based on printed conductors. They are arranged in the same way as the first type of heaters, however, a wire made of resistive metal is replaced by an etched metal film based on a polymer. By printing or etching on a metallized film , a ribbon-like conductor is created, which has the form of an open labyrinth. When it is connected to a current source, it heats up, after which it heats the mirror through a reflective layer. The third type is represented by mirrors with a combined reflective layer, which acts as a heating element. In such mirrors, a thin layer of metal is sprayed onto the back of the reflective layer through the insulating layer of varnish in the form of an aluminum amalgam, and a labyrinth conductor is formed from it. In some cases, the heating element is glued to the reflective layer, and the glue layer serves as an insulator. You can set your own mirror heating.
The main characteristics of mirror heating
The first characteristic is the time to warm up to operating temperature - this is the time that is necessary for complete thermal cleaning from frost or moisture during initial start-up. A positive difference in the temperature of the heater and the outdoor temperature. Duration of de-icing - this parameter is determined only empirically in laboratory conditions. Thermal power, specific power and efficiency.
As you can see, in many cases the installation of mirror heating is very relevant.