An electric dryer must be vented to help prevent it from overheating and catching fire. An electric dryer may be vented either indoors or outdoors. Gas dryers must be vented outdoors.
Most homes have designated laundry areas where the builder has installed a vent. In this case, the dryer can easily be vented to the outdoors. An aluminum dryer hose should be attached to the dryer's vent pipe, which is usually located on the back of the dryer. The other end of the dryer hose should be attached to the vent pipe on the wall. The dryer hose should be cut to an appropriate length. Unnecessary length in the dryer hose can collect lint and increase the risk of fire.
If an electric dryer cannot be vented to the outdoors, it may be attached to an indoor dryer vent. Indoor dryer vent kits are available in most home improvement stores. When venting a dryer indoors, an aluminum dryer hose is attached to the dryer's vent pipe. The other end of the dryer hose is attached to a container that is filled with water. When the dryer is turned on, the air vents to the container, which releases the warm, moist air back into the room.