Do Bathroom Fans Use Cold Air?(Yes! See how)

Bathroom Fans Use Cold Air

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Do Bathroom Fans Use Cold Air?

A bathroom fan is an important part of a bathroom; its usefulness stretches beyond taking a shower to after a shower.

As you take a hot shower, it’s unfortunate that the hot water will turn chemicals like chlorine into vapor.

And as you bathe, you will easily and unknowingly inhale the vapor into your lungs.

Chlorine inhalation is harmful to your lungs as it results in complications, including asthma and allergies.

Additionally, chlorine is carcinogenic and absorbed into the bloodstream; it will cause cancer. 

But you might be asking, do bathroom fans use cold air? Yes. When your fan runs, it will blow out hot air and humid air.

Colder air but not humid air comes in and replaces sucked-out air.

A bathroom exhaust fan removes stale, humid, and impure air from your bathroom. When your bathroom fan is running, it gets rid of steam from your bathroom.

Fans will also remove the foul odor, preventing it from spreading to the whole house.

If you have excess humidity in your bathroom, you will experience the breeding of mold and other microorganisms.

Additionally, high humidity leads to paint peeling from your bathroom walls. As you take a shower, it’s advisable to have your fan running to get rid of any vapor before it builds up.

This is very key in reducing chlorine inhaling. Chlorine gas escapes with vapor when bathing with hot water.

But you should also open the bathroom door to help dry your bathroom faster and get rid of any unwanted gases or air.

Consequently, leaving out the doors open will maximize the flow rate of air. Again, the exhaust fan will remove the bad odor from your bathroom.

While keeping the doors opened effectively removes the odors, it might also lead to a situation where the odor escapes into other rooms.

Therefore, you might find it better to keep the doors closed if this comes as a significant concern.

Can You Insulate Over Bathroom Fan

Yes, it’s needful to insulate over a bathroom fan. A bathroom needs to be sufficiently ventilated to evade unnecessary damages.

If you do not have sufficient ventilation, your bathroom and the entire house are at risk of getting excessive moisture.

The walls and the ceiling will be the first and most affected culprits. As a rule of thumb, insulation needs to be placed over bathroom fans.

Fortunately, modern bath fans scarcely generate excessive heat. Consequently, they can be covered without the need for additional clearance.

Care needs to be taken to cover holes in the housing and prevent loose insulation from entering the fan housing.

On the other hand, older bathroom fans generated a lot of heat and were not very energy efficient.

This accounts for the reason a box covered them before adding the insulation. This becomes unnecessary for modern fans due to modern technology.

And placing insulation directly on the housing suffices. Before insulating your bathroom fan.

You will need to read the fan insulation manual and see if the manufacturer recommends placing insulation directly above the fan housing.

Start by sealing all holes in the fan housing and thus prevent dust from entering the fan housing and then falling into the bathroom.

By caulking around the fan housing, you will eliminate any possibility of energy loss and dust from falling.

Also, insulate the duct as well.

Does The Exhaust Fan Bring In The Fresh Air?

It depends. This will happen if an exhaust fan is placed at the highest point in a room, being powerful enough to create a significant pressure difference in the room.

This will enable more natural cool air to flow from the atmosphere. The atmosphere outside is at a cooler temperature, hence making it possible.

However, this might not be possible in a humid atmosphere. But a powerful and desert cooler exhaust fan will achieve the objective.

All the same, you will need to understand that there is a key role played by the temperature outside and inside the room.

For instance, if the room temperature is much higher inside than it’s outside, there will be no reason your exhaust fan will not bring in the fresh air.

Indeed, it will be cooled to a couple of degrees above the outside temperature.

If the room temperature is 28 degrees Celsius and the outside temperature is 21 degrees Celsius, it’s possible to cool the room up to 23 or 24 degrees Celsius.

However, all this will depend on the room and the exhaust fan size we are dealing with. Otherwise, it might take some time.

This means that it’s not possible to cool your room by, say, about 10 degrees Celsius. Yes, an exhaust fan will only bring fresh air into the room.

It’s not disputable that you can bring the room to a slightly lower temperature, but this will be around 3 to 5 degrees Celsius.

Again, the second law of thermodynamics states that “heat of its own cannot flow from a low-temperature source to a high-temperature sink without doing external work.”

Consequently, it’s best to use an evaporative air cooler in areas with relative humidity low enough to work or use an Air conditioner.

Does The Exhaust Fan Help With Dust?

Yes, but it depends. Exhaust fans are designed to pull hot air out of a larger area or even a room. An exhaust fan performs this function effectively.

When I was living with my parents, our house had an unfinished upper floor in my younger years.

During summer, it would be very hot up there, forcing my father to use a large exhaust fan to draw the heat out of it.  Back in those days, it worked.

This helped get rid of excess heat (and it was extremely hot), although it can’t take the place of an air conditioner.

Yes, an exhaust fan will cool things off, at least a bit, making a place more bearable if you don’t have any other way of cooling your room.

Although it might not remove all the odors, an exhaust fan will remove some odors. However, I am more comfortable suggesting another way of dealing with the odors.

You might consider using essential oils in your electric warmer. Alternatively, get a shot of your favorite scent of Febreze.

Any dust visible on the exhaust cover indicates that your vent is dirty and needs cleaning. You can examine the exhaust cover well using a flashlight to determine how dirty it is.

Can You Insulate Around A Bathroom Fan?

The short answer is yes, you can. Essentially, bathroom exhaust fans need to be insulated, but this insulation needs to be done properly. There are scores for this.

But insulation cannot be put on the actual fan or its fastenings in the bathroom. Yes, what you insulate is the air duct that connects to the fan.

And this is normally found in your attic.

There are scores of things that affect the quality of the air in your bathroom. It might be a stench or just steam.

At other times, the harsh chemicals used in cleaning the bathroom are the culprit. If you have a well-insulated exhaust fan.

You might not have any reason to worry about any of these as it does an efficient job of venting out all such things.

The relevance of this is less of the above things in the air, which is good for your health and comfort.

A well-insulated exhaust fan will do a better job in the circulation of fresh air into the room.

This will result in less stagnant air in the room, meaning pollutants won’t hang around long.

This is because the environment will not be livable for things like mold and other spores. Again, foul odors will not survive where there is a constant flow of fresh air.

Failure to properly insulate an exhaust fan will lead to a situation where moisture doesn’t circulate effectively out of your bathroom.

Not getting rid of enough moisture leads to excess moisture in your bathroom.

Do Bathroom Fans Draw Air From Outside?

Yes, when operating a bathroom exhaust vent fan, you are essentially removing stale air from inside your bathroom and replacing it with outdoor air.

The bathroom exhaust fan is meant to remove excess odors and moisture from your bathroom.

As the air energy in the exhaust fan is lost, a bath fan will need to continue operating to remove excess moisture/odors.

While there will be an energy loss, it’s insignificant compared to the advantages you get using the fan. Such advantages are health-related.

Alternatively, you can install a heat recovery ventilation system (HRV) to pull air from your bathroom.

Capture a percentage of the exhaust air’s energy, and then transfer it to the fresh air meant to make up for the exhausted air.

Unfortunately, HVR will continue to remove moisture from your house even during the winter months when needed.

Still, HVR continues to add moisture into the home during hot, humid summer when not wanted.

But you will not find solace with an energy recovery ventilator (ERV) since it leaves outdoor moisture outdoors.

Still, ERV leaves interior moisture indoors and is therefore not helpful in removing unwanted bathroom moisture.

Consequently, it is best to stick with bathroom fans for moisture removal and refrain from worrying about the introduction of moisture or energy loss.

Remember, the fans located in rooms with high moisture concentrations; will scarcely bring in moisture levels being exhausted.

Can You Put An Exhaust Fan In The Shower?

Yes, particular exhaust fans have a UL listing for over-a-tub (or over-a-shower) installation on a GFCI circuit.

Units with a heating function on them cannot be installed over a tub or shower. Subsequently, you might also ask, can I have an extractor fan in my shower?

Well, these kinds of fans have been particularly designed for installation inside shower enclosures on bath areas. They come with high IP ratings to guarantee user safety.

Additionally, they boast a straightforward installation as they come supplied with an installation kit.

Still, it’s necessary to acknowledge that extractor and exhaust fans need to be vented to the outside of buildings with a vent cap.

Excessive moisture is not good for the fans as it will dictate condensation on insulation and roof members.

When this happens, mold will come, making your home unlivable. But remember, you do not need to vent your extractor fan to the attic.

Interestingly, bathroom fans are not required building codes for some municipalities. As you know, different municipalities have different requirements.

Fortunately, some do not draw a hard line when it comes to requiring exhaust fans.

In such municipalities, ventilation in bathrooms is a requirement, but it can be from a window or fan, your choice.

Can You Install A Bathroom Fan Above A Shower?

Yes, but it’s not the best place to install it. To maximize their effectiveness, most exhaust fans work best when installed near the bathing area.

From this position, exhaust fans easily remove odors and moisture, adding to the home’s safety by reducing fumes from cleaning chemicals and agents.

These can potentially cause serious health-related issues.

Unless you are dealing with exhaust fans that are UL listed for over-a-tub installation, it might not be appropriate to install a fan above a shower.

If your bathroom has both a shower and a whirlpool or a tub and shower, your fan can go anywhere between the two fixtures.

But you will not want to install units with any heating function over a tub or shower.

The position taken by your bathroom fan makes a big difference in how effective it becomes in removing moisture.

Additionally, it makes a significant difference in how such airflow affects people who use the bathroom.

The ideal position for the bathroom fan is on the ceiling, close to your shower but not directly over the shower.


Bathroom fans use cold air.


Hi! I' am Tom. I was a manager in one of the biggest stores for over 10 Years, am also an SEO by night. I don't like to call myself a blogger; they are very analytical, do email marketing, and know all SEO stuff. I faced many questions from customers about different products, and there was hardly any help on the internet. After learning all the things about these products as a manager the hard way, I decided to start a blog and help other people.

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