Washing Machine and Dryer Combo. Washer-dryer combos are not the same as a single set of washing machine and tumble dryer, but rather are a single laundry machine that has one cabinet for both the washing machine and the dryer. While they are not popular everywhere, for people who live in very small homes or apartments, people with limited space to hold bulky machines, they can be great because they do not take up very much room at all. They are economical with space for domestic laundry appliances.