It is obvious how paper towels work to dry our hands – absorption. With air powered, wall mounted hand dryers, there is slightly different physics at work. Here is a quick explanation of how these wall mounted hand dryers work so efficiently at getting us on our way. The first piece of physics involved is pressure. You see, the air coming out of wall mounted hand dryers is coming at a speed that it will push excess moisture from your hands. Combine this with the second bit of physics involved – heat – and you get evaporation. Most wall mounted hand dryers suggest rubbing your hands together as they dry. This provides friction, which leads to more evaporation of the moisture. Between the pressure, heat, and friction that come into play when using wall mounted hand dryers, you can see why they have become the dryer of choice for many public restrooms.