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Ventless Dryers | Will They Increase Humidity?

Have you noticed that the air feels a little stuffy or that the surfaces are covered in condensation after running your ventless dryer? If so, you may begin to wonder what happens to the moisture that would typically be vented outdoors in a conventional dryer.

In short, most of it is removed in the form of water, but some of it is also able to escape out of the dryer into the room. This means that humidity levels can be affected. Let’s take a look at what that means for your home and how you could prevent it.

While ventless dryers usually don’t affect humidity levels drastically, it can happen if the room they are kept in is enclosed and lacks any ventilation, especially if it’s also cold. In these cases, the moisture and condensation created by the dryer accumulate and consequently increase humidity.

Ventless Dryers Do Affect Humidity Levels

Despite ventless dryers having their own way of removing most of the moisture from the dryer air, they will still impact the level of humidity in the room. With that said, this increase in humidity doesn’t necessarily have to be a problem. 

The humidity created by a ventless dryer will be much more of an issue in rooms without proper ventilation. This is especially true if the room in question is a small enclosed space or it keeps a cooler temperature.

How Do Ventless Dryers Work?

There are two types of ventless dryers: a condenser dryer and a heat pump dryer.

A condenser dryer operates by making use of both a heating element and a heat exchanger. 

inside a dryer

Much like in a conventional dryer, the air is heated up in a condenser to dry the clothes. However, rather than venting the hot, moist air outside, the heat exchanger cools the hot air inside the dryer. This condenses the evaporated water back into liquid. 

While some models can be connected to a drain hose, others collect this water in a container that must be emptied manually.

A heat pump dryer is more efficient than a condenser dryer as it utilizes a compressor and heat exchanger to recycle and reheat the air inside itself as a closed system.

So, instead of the hot air just being cooled and then reheated with more energy, the heat from the air is used to heat the next cycle of air.

Any moisture turned into liquid through the drying process of heat pump dryers is also either drained out or collected in a water container.

How This Affects Humidity

Of the two types of ventless dryers, a condenser dryer is more likely to have a larger impact on the humidity levels in your home. That said, both types of dryers have the potential to increase humidity.

However, ventless dryers generally don’t release enough of the hot, humid air to significantly increase rooms temperature or humidity unless the dryer is in a small, enclosed, or cool room that doesn’t have sufficient airflow.

By sufficient airflow, I mean there should be a way for the air to get out, especially during and right after you run a drying cycle. Ideally, there will be a window or a door that you can leave open.

If the moist air has nowhere to escape, it will start accumulating. This elevates the humidity levels and increases the likelihood of mold and mildew, which prefer moist environments, growing in the room.

mold inside the room

The Water Container Should Be Emptied Regularly

As covered, some ventless dryer models will collect moisture in a container that must be manually emptied. These containers should be dumped out regularly, ideally, after every use.

If left to sit, the water left in the collection containers can leak, and as a result, it can also increase the humidity levels in the room.

In case you find emptying the water container inconvenient, a fantastic solution is to connect your dryer to the already mentioned drain hose so that the water can drain automatically. This is a setup based on choice; you don’t need to have an available drain to have a ventless dryer.

However, this way, you won’t be able to reuse the collected water in some of these cool earth-friendly ways.

Ventless Dryers Can Cause Condensation

The process of heat exchange in ventless dryers means that not only does the moisture inside the dryer condense and drain, but some condensation can develop under or outside of your dryer.

Think about how a cold water bottle begins to sweat when exposed to room temperature. A similar concept applies here. The condensation can either form as the warm air reaches the colder surfaces such as walls, floors, and windows, or inside and on the dryer itself.

If too much condensation occurs and it has nowhere to go due to the lack of ventilation, it will increase moisture levels in the room and create a favorable environment for mold.

Condensation formation is typically less of a problem if the dryer is kept in a warmer room, as the amount of condensation outside the dryer significantly increases in cooler environments.

This means that the matter gets worse if your laundry room is not insulated or if you keep the dryer in an unheated basement.

You should also regularly check and clean both the underside of your dryer and its condenser coils to help it operate as well as possible.

Only Install Ventless Dryers in Ventilated Rooms

If your laundry room has adequate ventilation, then this is the ideal space for a ventless dryer.

It is not recommended to install a ventless dryer in a room without proper airflow. However, if you do decide to do so, then it is crucial to ensure that you ventilate the room as well as you can to prevent mold, mildew, and other water damage.

While the best option would, of course, be opening a window or, if the room is already humid, perhaps even installing an exhaust fan, although this is not feasible for everyone. 

Should that be the case for you, you can keep the door(s) to the rest of the house open to allow for natural air circulation. Alternatively, you can try installing a louver (amazon link) or a louver door (amazon link).

You may even consider placing a dehumidifier (amazon link) inside the room to remove some of the moisture.


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