After the car is completely washed, the final step in the automated process is the dryer. Much like a giant hair dryer, the dryer in a car wash heats large amounts of air and forces it out through a series of nozzles. These heated blasts of air rapidly dry the surface of the car.
The dryer has a large, flat, round section just before the nozzle opening. This section is called the silencer. Like a muffler or the silencer on a gun, the dryer's silencer deadens the noise created by the air being forced through the system.
Some car washes apply a special chemical after the final rinse, before the dryer, that speeds up the drying process. The temperature and force of the dryer can be set. Most full-service car washes set the dryer lower than exterior-only car washes. This is because a full-service car wash usually has attendants who hand-dry the car with towels to remove all of the water.