Bathroom Dehumidifier vs Exhaust Fan | Which is Better?

In this article, we’ll weigh the pros and cons of a bathroom dehumidifier vs exhaust fan, and show you how to determine which is better for your purposes.

If excess and lingering humidity is a problem in your bathroom, either a humidifier or an exhaust fan could be the solution. Both appliances will remove the moist air and help to prevent mold growth and lingering dampness.

But that’s where the similarities end. They do different things well and produce different results.

In short, if you have weak ventilation and your bathroom remains humid long after you’ve had a shower or bath, a dehumidifier is the appliance you should consider. 

However, if your ventilation is adequate and your bathroom only remains humid for a short while after bath time, an exhaust fan could be your answer. 

It is more nuanced than that, though.

We’re about to show you the differences between bathroom dehumidifiers and exhaust fans, examine their strengths and weaknesses, and arm you with the knowledge to make an informed choice.

Keep reading.

Bathroom dehumidifiers

Small windows are often a problem in modern bathroom design. The ventilation is poor, and humidity becomes a persistent issue. In this case, a dehumidifier is the best option.

Bathroom dehumidifiers extract moisture from the air in the bathroom. It is collected in a water reservoir, which you have to empty every thirty hours, on average.


These units work fast and feature precise humidity control all the time. They measure the moisture in the air and switch themselves off when it reaches the desired level. Once the humidity rises above the preset level, the unit kicks into operation again.

Bathrooms require smaller dehumidifiers, and these are generally fairly cheap and easy to set up.

Above all, these units require no installation. Take it out of the box, plug it in, set the desired humidity level (43% is recommended) and you’re good to go.


Even though they’re small, dehumidifiers do take up some space. If your bathroom is a tight fit this may be a problem.

These units need an electrical outlet. Many bathrooms don’t have that.

The water reservoir needs to be emptied every 30 hours or thereabouts.

Exhaust Fans

These units will extract the humidity from your bathroom fast. They’re quicker than a dehumidifier.

They work by replacing the entire volume of air in your bathroom several times an hour while running.


Exhaust fans are quick. They only have to run while you’re in the shower or having a bath. Once you’re done, they’re done.

Because they’re built-in units, they don’t take up space in your bathroom. They’ll sit flush against a wall, ceiling, or window.

Some units feature a heater element, which makes them great for winter.

Some units even have a Bluetooth speaker so you can listen to music while you’re in the bath or shower.


Exhaust fans need to be installed. The installation process is often too complicated for anyone but the most ardent DIY enthusiasts.

The cost of a professional exhaust fan installation could be as much as 4 or 5 times that of a dehumidifier.

Window-fitted units are cheaper to install but they allow bugs and other outside critters access to your bathroom.


Although an exhaust fan and a dehumidifier do things differently, the desired result is the same – a less humid environment in your bathroom.

An extractor fan works by producing sufficient airflow to change the air in your bathroom (ideally) 8 times per hour. It is critical to get the right size exhaust fan for the square footage of your bathroom. Determining this is a bit of a math quest. But once you’ve measured your bathroom, every exhaust fan manufacturer should have a chart available to help you determine which model is best suited for your requirements.

A dehumidifier doesn’t change the air in the bathroom – it simply extracts the moisture from the atmosphere. These units can be preset to bring humidity levels down to an ideal level, and then sustain them. That means instead of replacing the air from your bathroom as an exhaust fan does, the dehumidifier will control the humidity levels instead.

A bathroom exhaust fan is typically installed in a wall, ceiling, or window. So, it doesn’t occupy any space in the bathroom.

A dehumidifier is not a built-in unit – space can be a factor in smaller bathrooms.

Exhaust fans rely on the power of a fan to extract air. That means they’re noisy. Finding a unit that is quiet enough can be difficult.

Dehumidifiers are by nature quiet. They switch themselves on and off as needed. At worst they emit a soft purring sound.

An exhaust fan often has a built-in light. This combination typically means when you switch the light on, the exhaust fan starts to work. You have little or no control over that.

A dehumidifier runs all the time until the water reservoir is full. It’s a set-up-and-forget appliance. Some have lights, but many don’t.

An exhaust fan doesn’t require any operational maintenance. It simply needs to be switched on.

A dehumidifier pretty much runs itself, but you do have to empty the water tank on average every 30 hours.

Some exhaust fans have a heating element for winter.

Dehumidifiers don’t have a heating feature.

Which is the best overall

If you aim to simply extract moisture from your bathroom by using brute force, then an exhaust fan will do just fine. Also, if your bathroom has fair to good natural ventilation, and if the humidity is not persistent, an exhaust fan will be your go-to.

However, if you want to regulate the humidity in your bathroom and keep it at ideal levels 24/7, then a dehumidifier is the unit for you, without a doubt. A dehumidifier is also by far the better choice if the humidity in your bathroom is persistent, and if you don’t have adequate ventilation.

How to get your hands on an exhaust fan or dehumidifier

Once you have your bathroom specs worked out, and decided between a dehumidifier or an exhaust fan, there are various online options available.

Here is a link that will take you to good dehumidifiers for your bathroom.And here is a link that will take you to good exhaust fans for your bathroom.


Shawn Willis is all about humidifiers. After working for some of the biggest names in the industry, he started HumidifierGuys with Scott Dawson. Now, the dynamic duo helps others figure out what they need in their next humidifier.

Shawn is an avid sports fan, motorcycle enthusiast, and has two dogs named Whiskey and Boba.