Bathroom Dehumidifier vs Exhaust Fan — Which is Better?

Exhaust fans and dehumidifiers have long been used to tackle humidity issues indoors. But which one is actually better for you? In most cases, a bathroom dehumidifier is the best choice. However, not all bathrooms have enough space and not everyone can afford it or have the time for regular maintenance. Will an exhaust fan accomplish the task just as well? We aim to answer all of these questions you have about bathroom dehumidifiers and exhaust fans and help you find which product is best for you. 

The bathroom is often damp and humid. Taking a bath or using the shower releases excess moisture in the air and water droplets form when this moist air hits a cold surface such as the bathroom walls, mirrors, or windows. No matter how hard you try to keep it dry, the bathroom is exposed to moisture regularly. Over time, this can encourage mold growth, leading to health problems and structural damage. You’ll need help from a bathroom exhaust fan or dehumidifier to eliminate damp air and replace it with fresh, dry air.

Bathroom Dehumidifier vs Exhaust Fan — What is the Difference?

Although both exhaust fans and dehumidifiers are often used to help reduce humidity, they work in completely different ways. The main difference is that exhaust fans simply circulate the air inside, while dehumidifiers actually extract moisture from the air. 

Exhaust fans work by pushing humid air out of an enclosed area, which in turn sucks in fresh air from outside through a vent or window to replace it. In the case of a ceiling exhaust fan, the air that’s drawn out from the room passes through a ducting system and. As hot air is vented outdoors, it reduces the temperature inside without using an air conditioning system.

Exhaust fans do not control the humidity level. They cannot replace an air conditioner, they simply act as a ventilation system that circulates air within the room, or between the inside and outside. This can provide some relief from the dampness or heat inside the rooms. 

Dehumidifiers work by reducing the amount of moisture in the air. They accomplish this through different methods. The most common is through condensation. The humid air is drawn through a fan and passes through a cold surface. The moisture condenses into water which is collected in a tank or drained through a hose. Dryer air is then released to the room.

Another type of dehumidifier uses a desiccant substance which acts like a sponge. Moisture separates from the air molecules and clings to the desiccant, while a heater warms the saturated desiccant so it can adsorb moisture again. Warmer, dryer air is then exhausted.

Exhaust Fan Improves Air Circulation

If you only need to reduce moisture for a short period of time, say, after a shower, then an exhaust fan may be ideal. Weigh the following pros and cons to see if an exhaust fan is best for your bathroom.

Advantages of Using an Exhaust Fan

Keep your bathroom dry by releasing hot and humid air and bringing in cool, fresh air from the outside. This can help stunt the growth of mold and mildew or other common allergens in the air.

An exhaust fan takes little space. Counter space is valuable especially in a small bathroom. While a dehumidifier requires to be placed on top of a level surface, an exhaust fan can be mounted on a wall or ceiling.

A window exhaust fan is easy to install and set up. Most exhaust fans can fit into a wall or window for easy installation. A ceiling-mounted fan is a different conversation.

No drainage system means less maintenance. Anyone can use an exhaust fan. Just turn it on, let it run for a time, then turn it off when moisture level is significantly reduced.

Disadvantages of Using an Exhaust Fan

Exhaust fans cannot control the humidity level. The air quality and humidity depend on your outdoor environment. If it’s particularly humid outside, then the exhaust fan will take in humid air and circulate it within the bathroom.

Exhaust fans create negative pressure inside your home. When air comes out through the exhaust fan, air must also come in through some other way. If there’s no window or vent readily available, air may seep into cracks on your walls.

Ceiling exhaust fans can be expensive and difficult to install. They need ducting to direct the humid air outside. Some units may need attic access to connect the exhaust vent to the fan.

Some residential areas, like an apartment, may forbid the use of exhaust fans in the bathroom. This is because the indoor air as well as the odors and whatnot are released outside and potentially into the space of other residents. In this case, you just cannot have an exhaust fan installed in your bathroom.

Best Exhaust Fans for the Bathroom

As mentioned, some exhaust fans can be mounted on the wall or in a window, or permanently installed in the ceiling. I’ve picked one of each to help you start looking for the right model for your bathroom.

Wall-Mounted Exhaust Fan

SAILFLO 6-inch Bathroom Window Exhaust Fan

This 176 CFM fan works as a two-way ventilation fan to release air in either direction. It can eliminate moist air from the bathroom as well as take in fresh air from the outside. You can install it in place of the bathroom window or through a hole in the wall. The drawstring acts as the power switch. On the first pull, the fan exhausts outside; on the second, the blades reverse movement to draw air inward; on the third, the fan stops and the louver closes. 

Ceiling Exhaust Fan

Broan-NuTone AE80 InVent Bathroom Exhaust Fan

This quiet Energy Star certified ventilation fan operates at 80 CFM and 0.8 Sones to help circulate air in bathrooms up to 75 square feet. With the TrueSeal Damper Technology, the fan can reduce air leaks by as much as 50% compared to comparable models. The AE110 is specially designed for bathroom installation over tubs and showers. With the GFCI circuit, you can place the fan exactly where you need it to suck out steam before it expands out and condenses on the walls, glass, or mirrors.

Dehumidifier Controls Humidity

If your bathroom has consistently high humidity levels throughout the day, it’s important to have it in control before mold problems arise. Although a dehumidifier is the better option overall, it may not be ideal for every type of home.

Advantages of Using a Bathroom Dehumidifier

A dehumidifier offers precise humidity control in the bathroom. Most modern dehumidifiers feature a humidistat which maintains the humidity level you set. You can leave the unit running and it will automatically turn off when the task is done or when the bucket is full.

It also provides more powerful moisture removal. With an exhaust fan, the air it takes in can only be as dry as the outside air, whereas with a dehumidifier you can program it to make the air as dry as you like.

Dehumidifiers for bathrooms are typically small and inexpensive. There’s also no complicated installation needed. Simply plug in, set it, and forget. The built-in features ensure the safety of your device even if you leave it running all day. 

Full-size units have an option for continuous drainage through a hose, while mini portable dehumidifiers have a tank large enough to hold at least two days worth of moisture.

Disadvantages of Using a Dehumidifier

A dehumidifier contains water and it also works with electricity. This can cause an electrical hazard if you’re not careful enough.

No matter how small, a dehumidifier will take up valuable space from your bathroom counter, table, or shelf. You must make sure it’s placed on a level surface for proper functioning and to avoid spilling water.

You need to empty the collected water in the tank. Dehumidifiers have an auto shutoff feature for when the tank is full. The unit will stop to avoid overflow and it will not resume until you empty the tank and place it back properly. This usually doesn’t take a lot of time, but it can be a hassle if you just got out of the shower and you’ll be late for work.

If you’re going to use a drain hose, you must make sure it’s secure in place to avoid leaking. The dehumidifier has to be in a higher level and the hose in a downward position from the drain outlet to the sink or drain.  

Best Bathroom Dehumidifiers

Depending on the size of your bathroom and how much moisture is present inside, you’ll need different types of dehumidifiers. I’ve chosen two models to get you started in your search.

Thermo-Electric Dehumidifier

Pro Breeze Portable Dehumidifier

This mini dehumidifier uses the Peltier effect or therno-electric cooling for an efficient yet whisper-quiet moisture removal. It’s smaller in capacity than the typical compressor dehumidifier for basements or living spaces. It can extract up to 18 ounces of moisture per day in a 250 sq ft. room while the tank can hold 52 ounces. It’s incredibly easy to operate with just one button for the power switch. Turn it on and it will immediately dehumidify and shut off automatically when the tank is full. This mini dehumidifier is ideal for the bathroom, bedroom, and other small spaces with minimal moisture.

Desiccant Dehumidifier

Ivation 13-pint Desiccant Dehumidifier

This desiccant dehumidifier works in a wider range of temperatures, from 33°F to 104°F. It’s small, light, and quiet since it doesn’t use a compressor. It removes up to 13 pints of moisture per day and the tank can hold 3.8 pints of water. You also have the option for continuous drainage with the included drain hose. Unlike the Peltier type dehumidifiers, this full-size desiccant allows more control over the operation. You can set the humidity level from 35% to 85%, change the fan speed, and adjust the air vents. The LCD display shows you the room conditions including humidity and temperature as well as the current working status. It’s perfect for the bathroom, bedroom, RV, or any space within 270 square feet. One drawback is the higher costs.

Summary

The bathroom is prone to excess moisture and its damaging effects. To prevent this, eliminate moisture and keep the air dry. Opening the window may be a good choice sometimes, until bugs come in during the summer, or you’re freezing in the winter. 

Exhaust fans can help by releasing the humid air and replacing it with fresh outdoor air. However, this isn’t always good for you or your house structure. The best solution for humidity control in the bathroom is a dehumidifier. It can reduce humidity down to a level you’re most comfortable in and keep it that way throughout the day. Whichever you choose, be prepared to perform the required maintenance if you want to make the most out of your investment.