Generally, tumble dryers are available in condenser, heat pump and vented tumble dryers. A condenser dryer works by collecting the moisture from the air in the dryer, then using a fan to cool it down and condense it into water, which is collected or drained away. Heat pump dryers use refrigerant to draw moisture from clothes, which is often a gentler option. A vented tumble dryer, meanwhile, heats up the air inside the dryer and uses a fan to vent moisture, leaving clothes dry.