Ventless washers and dryers use heat to draw moisture away from clothing, recycle the hot air, cool the air and drain the moisture. Ventless washer and dryer combinations eliminate the need for a hosing system to carry the warm, moist air to the outside.
Ventless condensation dryers use recirculated air to dry clothes, sending dry, heated air through clothes to dry them, and then using cooler, ambient air or cold water to condense the warm, moist air. These dryers draw in cool and dry air using a blower, and the air is sent through a heating system. This warm air heats the wet clothes and collects moisture, and then the air gets redirected to a condensing chamber. Cold water or ambient air helps the warm air to cool and condense, the condensed water is drained and pumped away, and the cooled air is redirected back to the heater so that it can continue to dry the clothes.
With ventless heat-pump dryers, air goes through a heat pump to condense the water vapor and send the water through a drain pipe. The air is then reheated to continue collecting moisture from clothes. Heat pump dryers are considered more energy efficient than condensation dryers.
Ventless washer and dryer combinations work well in homes where it is not easy to connect a dryer through vents to the outside. They use less energy than traditional washer and dryer combinations, although they tend to be more expensive than traditional models. Ventless dryers can often work with 110 volts or 220 volts of electricity, although some require cold water to condense and remove moisture from the air.