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?
Yeah, you should shake off the water first (12 times is a good number), then rub your hands to spread the water over your hands so your evaporating water on all parts of your hands.
Takes less than a minute and gives you completely dry hands. This works with type 1 and 3 mentioned by you. Type 2 like the Dyson Airblade work if you pull your hands through slowly but then they will take a couple of minutes to dry on their own. With type 2 shaking the water off is not important since the machine does it for you.