In some old neighborhoods, radiators have been used for many years, and you can see blackened marks on the walls. This is mainly due to the fact that the air rises after heating, and the dust on the ground also rises, and the air runs to the wall, and the dust falls on the wall. Therefore, after the radiator that has been used for many years is removed, there will be a blank mark on the wall, and there will inevitably be gray marks around it.
However, this problem is only found with traditionally shaped radiators. Many new radiators will make some R&D changes in the shape, change the direction of air flow by changing the shape of the radiator, and guide the hot air outward, so that it will not fall on the wall, which will avoid blackening the wall. Therefore, if the radiator at home has been used for a long time, you can replace the radiator with a new shape.
If you don't want to replace the radiator, you can also place some trinkets and plants on the radiator to change the direction of movement of the air flow through these objects to avoid dust adsorbed to the wall.
You can also put a small basin on the radiator and put a little water in it to increase the humidity of the air and avoid dust from flying.