I find there’s three types of hand dryers: the standard kind that blows really hot air to evaporate the water, the ones that blow strongly to push the water off the hands, and the ones that are supposed to do one of these but don’t. At my university almost all of the hand dryers fall into the third category.
Why are hand dryers like this, and am I somehow drying my hands wrong?
It has a clean roll and a dirty roll. Someone takes out the dirty roll and replaces the clean roll periodically. Apparently they typically have about 30 meters of cloth, enough for about 200 uses.
How often that is, depends on how frequently it’s used.
There are cleaning services that wash the cloth and swap them for you.
Interior diagram: