Individual condensing dryers use air-to-air condensers to remove the moisture from the air before sending it back though the drum. Hot, moist air exiting the drum is passed over a set of metal fins. Cooler, room temperature air is pulled from the room to pass over the other side of each fin, and the difference in temperature causes the moisture in the warm air to condense into drops of water, which are pumped to the same drain as the wash water. The warm dry air is circulated back into the machine; the room temperature air returns to the room virtually unaffected. (The estimated temperature increase in the laundry room is approximately one degree Fahrenheit for a ten by ten room.)