Do Bathroom Fans Remove Smell?

Bathroom fans do a good job of reducing the humidity in a bathroom after a shower. But bathrooms can also have bad odors from a range of different sources. In this article, I will explain whether bathroom fans remove smells.

Overall, bathrooms do remove smell from a bathroom. But only from temporary sources such as the toilet or shower. However, it won’t remove permanent smells that continue to give off an odor, such as mold or urine residue around a toilet.

Removing odors from bathrooms can also be done by keeping windows open. But, generally, keeping a door open means the odors can be smelled in the rest of the house. 

So, below will explain how long it takes a bathroom fan to remove temporary odors from a bathroom if it’s a good idea to run a bathroom fan all the time, and whether bathroom fans can eliminate odors.

How Long Does a Bathroom Fan Take To Remove Smell

A bathroom fan also called a bathroom exhaust fan, effectively removes bad odors from a bathroom. However, it often takes some time for bad odors to disappear when using a fan or opening a window. So, here’s how long it takes for a bathroom fan to remove bad smells.

On average, it takes 10 minutes for a bathroom fan to remove a smell. On average, a bathroom is 240 cubic feet (7 m3), and a bathroom exhaust fan removes 25 cubic feet of air a minute. Therefore after 10 minutes, most of the existing air in a bathroom will be removed by a bathroom fan.

Some bad smells are temporary, such as when someone takes a poop. And caused by tiny particles in the air. These are detected by your nose. Therefore, once a bathroom fan has removed the existing air in a bathroom. Bad odors from temporary sources will also be removed.

How a bathroom fan removes bad smells

Air flow system by exhaust fan mounted on wall

It’s a well-known fact that air being sucked out of space creates what is called, in physics, a vacuum. This sucks any air in the general area towards it. So, as a bathroom fan is running, any air inside a bathroom will be drawn towards the fan and blown outside.

When this happens, air will get sucked from under the door of the bathroom and through any open windows. However, if the wind is blowing past an open window, it will also suck out the air in a bathroom. 

You might have seen this happen if the bathroom is very steamy and you open a window. You can see the steam being sucked out and away from a bathroom by the wind.

A bathroom fan only removes that are from a temporary source

If there is a source of a bad odor that is permanent such as mold, running a bathroom fan will only reduce the smell but won’t remove it. The bad odors will be more noticeable as soon as the fan is turned off. 

If the source of the bad odor is not producing a lot of odor, then a bathroom fan will be much more effective. Whereas, if there is little to no airflow in a bathroom, the bad odors will accumulate and be much more noticeable.

Therefore, bathroom fans are most effective at removing temporary smells. Such as when a person goes poop. After a person takes a poop, there is a lot of bad smell in the air. But, after the toilet is flushed, the poop is completely gone. 

Therefore, there is nothing continuing to produce the bad smell. So, once a bathroom fan has removed all the bad-smelling air, the bad odor will also completely disappear.

Neutralizing bad odors with air freshener

A bathroom fan typically takes 10 minutes to completely replace the air inside a bathroom (source). However, air fresheners are great for neutralizing the odor and making it almost impossible to smell. 

Air fresheners will tend to remove bad odors from a temporary source such as a poop immediately. Especially if they are used both before a person takes a poop and after. However, like a bathroom fan, they will only mask bad odors that are coming from a permanent source, such as mold.

Should a Bathroom Fan Run All the Time

It’s easy to forget that a bathroom fan is on, and it can be left running for long periods. It can also seem like a good idea to keep a bathroom fan always running. But here’s a summary of whether there are any additional benefits to running a bathroom fan all the time.

In general, a bathroom fan should not run all the time. A bathroom fan is maximally effective after running for 10 minutes. After running for 10 minutes in an average-sized bathroom, there is no additional benefit to keeping a bathroom fan running.

Interestingly, a bathroom fan uses virtually no electricity and therefore has little to no effect on your monthly power bill. Even if you run it for many hours a day. I explained how much it costs to run a bathroom exhaust fan in this article about how long to run a bathroom exhaust fan for.

Do Bathroom Fans Eliminate Odors

Bad odors are unpleasant, and therefore it’s best to get rid of them sooner rather than later. Typically removing the source is a good first step, followed up by cleaning the affected area. But what role does a bathroom play in eliminating odors, and does it completely remove odors?

Overall, bathroom fans do eliminate odors. But, only odors that are caused by a temporary source, such as using the toilet or soap, and shampoo odors from taking a shower. Odors that have a permanent source, like mold, will not get eliminated by a bathroom fan.

Bathroom fans suck all the air out of a bathroom, which gets replaced by air that is drawn from underneath the door and the small opening around a door. If the door of a bathroom is open, it will take less time to remove odors and humidity in a bathroom. 

But, it has the drawback that odors and humidity will get into the rest of your home, depending on where a bathroom is located.

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