What Are Ventless Dryers, and How Do They Work?

Standard clothes dryers, also known as vented dryers, work by pulling in air, heating the air, and then discharging moisture through a dryer vent. The discharged air is full of moisture so it is sent through an airtight hose to a rigid vent placed in a wall and expelled outside. Sometimes, you don't have the option to put in a vent for this type of dryer. But there is another kind of clothes dryer that can be used indoors, particularly in small spaces: a ventless dryer.

A ventless dryer is designed so that it does not require a vent to expel air. However, some models of ventless dryers need a drain to dispel the moisture while others have a water collection tank. Read on to learn how ventless dryers work and whether one might be right for your needs.

How Does a Ventless Dryer Work?

When you shop for a clothes dryer, there are two types of ventless clothes dryers that have no output air vent and rely on other methods to get rid of the heated moisture-laden air: condensation dryers and heat pump dryers. All ventless dryers are powered by electricity due to the combustible nature of gases in a non-vented space, and you can find stackable ventless dryer models, as well. Both types of ventless dryers are designed to extract moisture from clothing the same way but each uses different technologies to get the job done.

Condensation Dryers

Like a traditional vented dryer, the condensation ventless dryer pulls in cool, dry air from the room. The air is heated and passes through the clothes to dry them; but instead of being vented outside, the air travels through a cooling device or heat exchanger. The heat exchanger cools the heated air causing the moisture in the air to condense and flow into a containment chamber within the dryer. As the air is dried, it is reheated and passed through the clothes again. The process is repeated until the clothes are dry.

Some models allow the water to be directed and discharged through a clothes washer's drainpipe. This is convenient if you can locate the dryer directly next to the washer or stack the two units. A condenser unit with a discharge unit needs the same attention as one with a containment chamber except for the need to empty the chamber.

Heat Pump Dryers

A heat pump dryer pulls air from the room and recycles the hot air until the clothes are dry. The air is passed through a heat pump where the cold side condenses the water vapor into either a drain pipe or a collection tank and the hot side reheats the air to use again.

How to Use and Maintain a Ventless Dryer

Just as with a vented dryer, there are maintenance steps that should be taken with a ventless dryer. If the maintenance is not done, the dryer must work harder to dry clothes, and will not last as long as it should.

Empty the Containment Chamber

After every load, the containment chamber must be emptied and the dryer lint trap cleaned to be sure that no debris or lint is clogging pipes. The water that is collected can be recycled to water indoor plants or gardens.

Empty and Clean the Lint Trap

Just like standard dryers, lint in a ventless dryer goes into a lint trap. Most lint traps are located just inside the dryer door. After every load, remove the trap and scrape away the lint. Once every two weeks or so, the lint trap should be washed with a bit of dishwashing soap and cleaned with a soft brush to remove any build-up from dryer sheets, fabric softener, or detergent.

Check and Clean the Condenser Unit

No matter how diligent you are about emptying and cleaning the lint trap, eventually, lint will accumulate on the condenser unit of the dryer. The unit should be checked and cleaned at least four times per year. If the condenser is covered with lint, it will reduce the efficiency and longevity of the dryer. Take these quick, easy steps to clean the condenser unit:

1. Remove the condenser unit from the dryer and take it outside or to a large utility sink.
2. Use a hose or strong flow of water to rinse each side of the unit to remove any lint build-up that may be inside.
3. Allow the unit to air dry until there is no visible water and there is no water caught in the unit.
4. Return the condenser unit to the dryer.

Provide Airflow

While a ventless dryer does not need an outside vent, it does require adequate airflow to operate properly or the humidity level can rise in your home. If the dryer is housed in a closet, the door should be open during drying cycles. It is also important to vacuum regularly behind and around the unit to keep excessive dust at bay.

Pros and Cons of Ventless Dryers

The overall benefit of ventless dryers is that they can be placed in any location in the home (depending on if you need a drain or not) and do not require the installation of a vent pipe, making them perfect for renters and small spaces. Ventless dryers are also as safe as conventional dryers and are more popular than vented dryers in Europe, especially in Switzerland where vented dryers are no longer allowed to operate.

The energy usage of ventless dryers is somewhat debatable. It may take ventless dryers longer to dry laundry, which uses more electricity, but they are also gentler on your clothing. However, heat pump dryers are said to use less than half the energy required by either condensation or traditional dryers.

Prices for ventless dryers range from unit to unit, but in general, condenser dryers tend to be slightly more expensive than standard vented dryers.