How Clothes Dryers Work

Air Circulation
Dryer airflow diagram
Dryer airflow diagram

You may know that the warm, moist air leaves the dryer through a hole in the back, which is usually hooked up by a pipe to a vent on your house. But where does the air enter the dryer?

Let's follow the path of the air through the dryer. The air is sucked into the dryer through openings in the outside of the machine. One fan drives all of the air through the dryer, but the fan is actually the last step in the process.

In brief, this is how the air makes its way through the dryer:

  1. It enters the body of the dryer through a large hole in the front of the dryer.
  2. It is sucked past the heating element and into the tumbler.
  3. It enters the door and is directed down through the lint screen.
  4. It passes through a duct in the front of the dryer and into the fan.
  5. The fan forces it into the duct leading out the back of the dryer, at which point it exits your house.

The first thing that the air hits is the heating element. After the air enters the body of dryer, it is sucked through the heating element, and then into the clothing tumbler.

Heating element

This is a standard nichrome-wire heating element, just like the heating element in a toaster (see How Toasters Work for details on nichrome wire). This heating element consumes lots of power -- 4,000 to 6,000 watts on most dryers.

The air is drawn through the heating element and into the holes in the back of the tumbler.

Metal stamping and heating element

The metal stamping on the right, with the big holes in it, makes sure that air can enter the tumbler only after it has gone through the heating element.

Tumbler and door

The hot air now makes its way through the clothes in the tumbler, and then into the holes in the door.

Door holes and slot

The air passes through the holes in the door, and out through the big slot in the bottom of the door which leads to the lint screen.

Lint screen and duct

The air is drawn through the lint screen and down a duct in the front of the dryer, where it enters the fan.

Fan and exhaust duct

The fan is a centrifugal type of device -- as it spins, it flings the air to the outside, sucking air from the center and forcing it out the duct at the back of the dryer. In the next section we'll see what makes the tumbler spin.