It's not that you have to have one, but it's good for couple of reasons. Say if you have a few loads of laundry to do, you'll need the dryer as you run out of space for hanging. Dryer also helps to fluffy up the clothes so they're softer as opposed to hang right from the washer. What I usually do is to put the clothes in the dryer for 10-20 minutes, then take them out to hang. Bad things about using dryer is using lot of power and your clothes faded from time to time due to high heat.