Frost or ice on your windscreen can affect your ability to properly see your surroundings. Removing ice or frost from glass will increase not only your own safety, but also that of others. It can also be illegal to drive without proper visibility.
Why remove ice or frost from glass
Removing ice and frost in a safe way will help to prevent damage to your windscreen, the time you spent outside in the cold temperature and the amount of effort you have to put into getting your windscreen clear again. A clear windscreen will improve safety, for you and the people around you and will prevent you from getting a fine from the police.
Removing ice or frost from glass
+ water mixture
A mixture of either 50/50 and (demineralised) water or 25% and 75% water, will help to liquefy the frost again. has a much lower freezing point then that of water, mixing it with water will make it more economical. Spraying it over the frost/ice will mix the solution with the water in the ice, effectively lowering its freezing temperature. Demineralised water will help to prevent waterspots.
Rinsing with water
This is a solution that is not without danger. When the water you rinse with is too hot, the temperature difference will cause stress in the glass itself. If that stress becomes to big, it will make the glass crack and break. Rinsing the windscreen with water that is just above freezing (between 2 and 5 degrees Celcius for example) would be safe. Note that it may take a while for the glass to become “warm” enough to stopt the water from freezing again.
White vinegar + water mixture
A mixture of either 50/50 white vinegar with (demineralised) water, or 25% white vinegar with 75% water, will help to melt the ice. It will also help to avoid re-freezing of the molted ice, because the white vinegar has a lower freezing point then that of water. This solution can be sprayed on the windscreen in a liberal amount and left for some times to do its job. Although it works, it might not be the quickest solution.
There are special product on the market that contain certain solvents (such as alcohol) to help melt the ice/frost and to prevent re-freezing. This are often sold in the form of a spray or a spraycan. These need to be applied liberally and left for a certain period to work. After that, the ice/frost should have been melted far enough to see through the windscreen properly.
This hard piece of plastic can be used to literally scrape the ice/frost from the windscreen. There are also metal variant on this, but they are not recommended as they can damage the glass. An ice scraper should not be used on body parts, or anything else then glass. They sometimes have a backside with ridges on it, these can be used to crush ice when its either really thick or frozen stuck to the glass.
Airco or blower
The airco inside your car often has a specific setting to defrost the window, or de remove condensation from your windscreen. Although this air will still be cold if you just started the engine, it will be warmer then the glass. And will help to melt the ice/frost. Note that it may take a while before it has proper effect. If you don’t have an airco, of you don’t have the dehumidify option, you can still set your blower to a high speed, aimed at the windscreen with a medium temperature. Don’t set the temperature to hot, because the temperature difference can cause the glass to crack!
Electric heated windscreen
Some cars are fitted with an electric heated windscreen, which means you can raise the temperature of the glass by using a special conducting wire that is inside the glass itself. This will make it easier for the ice/frost to melt and be removed more easily. Please note that this put a heavy load on the running engine, which might decrease fuel efficiency.
The windscreen cover is more of a prevention than a solution. This cover is applied over the windscreen before the temperature drops, making it less likely for frost or ice to form on the windscreen. This cover can be made from aluminium, but some people also just use a towel on their windscreen. The downside is that the cover can get stuck to the windscreen when the water/moisture between the cover and the glass freezes. Removing the cover without melting the frozen moisture/water can result in tearing the cover. Especially with towel (which absorb moisture very well), freezing can turn in a hassle to remove the towel before driving off.