Bathroom exhaust fans are rated for the amount of air they can move. The highest CFM bathroom fan will move the most air, while the lowest CFM fan will move the least air.
While the minimum bath fan size of 50 CFM will work fine in small residential homes, it will struggle to keep up with excess humidity in large rooms.
In this guide, we have reviewed and compared some of the highest CFM bathroom fans that will remove moist and stale air without a hassle.
What is CFM in Fan?
CFM or Cubic Feet per Minute of airflow is basically how many cubic feet of air the fan can move every minute. This should be a good indicator to help you determine what type of bathroom fans are best for your home and which ones will provide the most benefits in moving all that moist warm air out quickly.
Is More CFM Better Bathroom Fan?
The answer to this question is a resounding “yes.” A higher CFM rating means that the fan will be more effective at clearing out humidity and moisture from your bathroom, making it safer for you and anyone else who uses the room. In addition, having enough ventilation helps keep your home free of mildew or mold spores by maintaining proper airflow through it.
A quick guide to finding the right CFM for your particular needs: 100-400square feet = 400-900 CFM 800-1500sq ft = 900 – 1800CFM 1500+ sq ft=1800+CFM This scale can function as a guideline when trying to determine how much power you need depending on what size of space you’re trying to ventilate.
What is the Best CFM for a Bathroom Fan?
The best CFM for a bathroom fan is dependent on the size of your bathroom and how you use it. The standard range would be anywhere from 50 to 100cfm (cubic feet per minute) as recommended by most manufacturers, but this will vary depending on personal preference.
Remember that the higher the CFM rating, the louder the noise level it will emit. Therefore, suppose you are looking for something more powerful than what we have mentioned above, we recommend taking a look at our Top-Rated Bathroom Fans post or doing some research using Google Search by typing in “highest rated bathroom fans” and select an appropriate page with reviews about these fixtures first before making any decisions regarding which one to purchase upon its features such as noise, power usage, and other factors.
Can You Have Too Much CFM in Bathroom?
As with every product, you can have too much of something good. For example, if your bathroom fan is very powerful and has high CFM (cubic feet per minute), it might be so strong that the air in your bathroom doesn’t get adequately circulated or enough to maintain freshness.
You may need more than one fan for this job – especially if your room isn’t large enough. The best way to find out how many fans you need is through testing.
You can do that by placing the fans at different heights around the bathroom while running separately at high speed. This will help you see which fan generates a better airflow inside the space and then use all/additional ones accordingly.
Is it Bad to Oversize a Bathroom Exhaust Fan?
Many people wonder whether it’s a good idea to oversize a bathroom exhaust fan. The answer is yes. You can go ahead and do that as long as the manufacturer recommends an oversized unit for your space.
Oversizing will allow the high capacity ventilation fan to run quieter and more efficiently because there won’t be any strain on the motor trying to move air through restrictive ductwork or grilles.
If you install an undersized ventilator in your home, not only would it make noise but also eventually fail due to increased stress placed upon its components like bearings and motors.
And if this happens during peak summer months when you need ventilation most, then what? You’ll end up having to buy another one for replacement.
Another reason to install an oversized ventilator is its energy-efficient nature. Under-sized units require the high capacity ventilation fan motor to work harder, increasing electricity consumption and heat output in the bathroom, making it uncomfortable to use during summer months. Oversized units are much more thermally efficient due to reduced resistance in ductwork, so they don’t have to work as hard for the same amount of airflow as undersized ones, resulting in less power usage.
The last thing you want is your ventilation system failing when you need it most because that’s when health risks increase dramatically due stuffy, moist environment where mildew can multiply on walls and other surfaces. Unfortunately, this also increases risks associated with mold exposure like coughing, wheezing, watery eyes, runny nose, and other flu-like symptoms.
That’s why it is a good idea to install an oversized bathroom exhaust fan because they can handle additional moisture and humidity without breaking down.
Are Bathroom Exhaust Fans Standard Size?
Bathroom exhaust fans are not a standard size. They come in different sizes ranging from 50 CFM to 150 CFM. But it’s important to know the highest CFM bathroom fan you will need before purchasing one. It should be at least double the amount of air that needs moving during a typical shower or bath time for your home’s average family size and other uses like cooking while no showers/baths are running.
The most common residential bathroom fan size is 80 CFM. Most commonly, bathrooms are built with 70 or 100 CFM exhaust fans that do not meet code requirements. When there is no shower/bath running and cooking simultaneously in the same room as a shower/bath, you need at least 150 CFM to keep your home safe from mold growth and other health issues caused by moisture build-up on walls and ceilings.
How to Choose the Right Size for a Bathroom Vent Fan
While there are no hard rules for sizing a bathroom fan, you should consider the space of your room. The size of the bathroom exhaust fan is proportional to its ability to circulate air in larger rooms and areas with more occupants. If you’re building an addition or constructing new bathrooms, you must consider all factors so that every vent will work properly when installed.
Here are some of the factors you need to consider.
The Standard Way of Sizing Fans
Bathroom vent fans are measured in cubic feet per minute, or CFM, and are rated for the amount of air they can move. Bathrooms with dimensions of 100 square feet or less use customary high capacity ventilation fan sizing rules. The rule of thumb is that you require at least 1 CFM per square foot of room area.
To measure the area of your bathroom, divide the length by the width. For example, if your bathroom is 6 feet wide and 9 feet long, its square footage is 54. As a result, it should be equipped with a fan capable of delivering at least 54 CFM. However, there are a few factors to consider before you begin looking for fans.
The first step is to oversize the ventilation fan by a few inches. In our example, a 60 CFM fan is appropriate for a 54-square-foot space.
Second, if your bathroom has a jetted tub or separated areas or alcoves, you may want more than one high capacity ventilation fan.
The minimum allowed fan volume is 50 CFM, so if your bathroom is only 42 square feet, you’ll need a 50 CFM fan.
Buying for a Large Bathroom
If you have a large bathroom, exhaust fans can be sized to meet the number of fixtures. To calculate using this method, add up the required CFM ratings for all of the fixtures:
- Jetted tub – 100 CFM
- Toilet – 50 CFM
- Bathtub – 50 CFM
- Shower – 50 CFM
A 100 CFM fan is required for a bathroom with only a shower and a toilet, whereas a 200 CFM fan is required for a jetted tub, toilet, and shower.
Another unique calculation technique is the one for rooms with high ceilings (over 8 feet). Multiply the square footage by the ceiling height, divide by 60, then multiply by 8 (the suggested number of air exchanges per hour).
You May Need a Second Fan
If you have a toilet or shower area enclosed by a door, installing a separate exhaust fan for that space is essential. A 50 CFM ventilation fan will work in a tiny enclosure.
If you’re not sure what the best calculation is, try one of these options. Otherwise, make use of a calculation that takes into account the room’s dimensions. Just keep in mind that the fan requires fresh air to perform properly. If your enclosure’s door is closed, there isn’t enough space at the bottom of the door for ventilation.
When using the toilet or shower in an enclosure with a high capacity ventilation fan running, leave the door open slightly when the gap below the door is less than 5/8 inch. A louvered door that allows airflow might also be used as another option.
Other Things to Consider when Choosing a Bathroom Fan
The sound level of a fan is usually rated by its sone rating, which indicates the volume. A lower number equals a quieter fan. A fan with a sone rating of 1 or less makes about the same noise as a refrigerator.
The most popular types of ceiling-mounted bathroom fans are the ones that mount on the ceiling. They connect to an exhaust duct that runs through the attic or between floors. Wall-mount bathroom fans are intended for rooms where venting via the ceiling isn’t feasible. These fans usually vent straight through the wall and into the outside environment, with little or no exhaust ductwork. Some fans will function in either a ceiling- or wall-mount installation.
Check for any obstructions that could cause the high capacity ventilation fan to overheat the electric circuit. High-CFM fans use more electricity since they have larger, more powerful motors. In addition, features like lights and heating elements increase power consumption.
Most Powerful Bathroom Exhaust Fans Reviews
1. Broan-Nutone L400 High Capacity Ventilator Fan
- HIGH-CAPACITY FAN: Ventilation fan operates on two impact-resistant centrifugal blower wheels at 434 CFM, 2.3 Sones, and 120V for a powerful and effective performance
- HEAVY-DUTY: Features a sturdy, 4.5" x 18.5" metal duct connector to provide long-lasting use
- CUSTOMIZATION: Fan ducts horizontally, vertically, or in-line with a separate adapter for your convenience
- EFFECTIVE: Automatic backdraft dampers and permanently lubricated motors provide continuous and quiet operation
- VERSATILE: Install fan in ceiling or wall -wherever it's needed most! Not for use over tub or shower.
- 434 CFM 2.3 Sons, 120V, 1.4 amps
- 4-1/2" 18-1/2" duct connector
- Two impact resistant centrifugal blower wheels and quiet automatic backdraft dampers
- Painted white enamel steel grille
- Can be ducted horizontally or vertically
The Broan-Nutone L400 is marketed as a commercial ventilation fan that can be used in commercial buildings. True to this assertion, the fan has several features that make it worth considering if you are looking for the right tool to remove excess moisture and bad odors in large bathrooms in commercial buildings.
Its capacity to move air is amazing: 434CFM. This means that the high capacity ventilation fan can provide sufficient ventilation in rooms that measure as much as 450 square meters.
It has a very powerful brushless DC motor that is fully greased to reduce the noise level of the fan and operate without requiring constant repair. The fan is amazingly quiet with a loudness score of 2.3 sones.
Although this fan can be installed anywhere, including the wall or ceiling of your bathroom, the process is not easy. However, once you align the fan ducts properly, then the ventilation fan will be good to go.
- High performance because of the 434 CFM value
- The sturdy metallic body and connector ducts enhance its durability
- The fun ducts are easily customizable vertically, horizontally, or the standard in-line
- The installation process is long and complicated for non-technical users
2. Broan-NuTone L300 High Capacity Ventilator Fan
- HIGH-CAPACITY FAN: Ventilation fan operates on a single, impact-resistant centrifugal blower wheel with 308 CFM, 2.9 Sones, and 120V for a powerful and effective performance
- HEAVY-DUTY: Housing is constructed of 20-gauge galvanized steel and features an 8" round metal duct connector to provide long-lasting use
- CUSTOMIZATION: Fan ducts horizontally, vertically, or in-line with a separate adapter for your convenience
- EFFECTIVE: Motors are permanently lubricated to provide continuous and quiet operation
- IDEAL FOR LARGE ROOMS: High-capacity ventilation fan is great for conference rooms, public restrooms, and other areas in commercial buildings that require ongoing ventilation
The Broan-Nutone L300 is a heavy-duty fan ideal for use in large spaces that measure up to 310 square feet. These may be bathrooms and restrooms in commercial buildings, and conference rooms that need continuous ventilation.
The fan provides steady, powerful, and effective performance, thanks to the inclusion of high-quality components and the use of a 20-gauge galvanized steel housing for their protection.
Good fans should maintain a very low profile even if they are used in bathrooms and public restrooms in commercial buildings. Fans may be noisy because their moving components are not properly greased or they end up vibrating during operations.
Luckily, Broan-Nutone has been designed with these challenges in mind. It’s motor and other internal components are well greased. As a result, they can remain in excellent shape and operate silently for a long time.
Additionally, the body of the high capacity ventilation fan is sturdy enough to operate without much vibration. As a result, the fan maintains a very low profile.
The only disadvantage of this fan arises when you have a large space that requires ventilation. The 310CFM value limits this fan to spaces that are less than 310 square feet.
- High-capacity fan suitable for use in large spaces like commercial restrooms
- Low vibration during operations maximizes its durability and minimizes noise
- The installation process is straightforward and easy for anyone to follow
- Unsuitable for use in very large spaces that measure over 350 square feet
3. Delta BreezProfessional Pro300, 300 CFM Bathroom Exhaust Bath Fan
- ENERGY STAR qualified with Brushless DC Motor technology
- Quiet operation at 2.0 Sones
- Ceiling mount ventilating fan rated for continuous running
- Energy efficiency at 7.3 CFM/Watt
- Green LED indicator light to show power is on
Although this fan has been made for use in large bathrooms, it can still be used in large areas that require continuous ventilation, including work areas and recreation rooms.
It has an above-average airflow capacity of 300CFM, which is enough for mid-sized spaces such as standard bathrooms and kids’ rooms.
This fan is excellent for use in the bathroom for two reasons: it is completely water-resistant and has built-in dampers to protect back drafting.
When drafts of air get sucked back into your fan, they end up causing the fan to overwork. This results in higher power consumption rates.
There is a small green LED indicator light that you can use to tell when the fan is working or not. This can be helpful particularly when you are installing the fan for the first time and would like to test whether it is functioning.
Because of its low noise level, the small indicator light is the only way of telling that the ventilation fan is powered on and working.
- Delivers value for money because the motor has been engineered to run continuously for 70,000 hours
- Great user experience because of several features, such as the LED light indicator
- Operates with minimal distraction because of the 2.0 sones score
- Installing this ventilation fan on the ceiling may require cutting for additional space
4. Panasonic FV-30VQ3 WhisperCeiling Ventilation Fan
- Ceiling-Mounted Fan: Made with high-quality motors and blade design; wears at slower pace
- Easy-Install Fan: Detachable adaptors, secure duct ends, adjustable mounting bracket, easy wiring
- Better Air Quality Ventilation Fan: Designed with a built-in damper to prevent backdraft
- Guaranteed to Last: Panasonic ventilation fans use less energy to move larger volumes of air
- Code-Compliant Ventilation: Energy Star certified and complies with the latest codes and standards
The Panasonic FV-30VQ3 is one of the most amazing bathroom fans with mid-level technical capabilities. The greatest thing about this fan that you will enjoy is the way it moves fairly large volumes of air silently.
Some fans with a CFM of over 270 tend to be noisy whenever they are set to operate at the highest speed level. However, this fan remains fairly silent yet its airflow capacity is 290CFM.
This is due to the excellent engineering of the high capacity ventilation fan and housing. With minimal vibration and a well-greased motor, the fan can only produce 2 sones of sound when operating.
Its installation, however, may be more complicated than you may think. The recommended procedures for installation using 6-inch ducts and the incorporated double hanger-bar system may be problematic at times.
But if you understand how to use the hanger system, then it will be easy to position this great ventilation fan and enjoy its amazing ventilation capabilities.
- The double hanger-bar system enables ideal positioning for optimal performance
- Can be installed directly over a bathtub using a GFCI protected circuit
- The heavy-duty housing guarantees longevity thus cutting down on repair and replacement costs
- Managing the double hanger bar during installation may take longer than expected
5. BV Ultra-Quiet 200 CFM, 2.0 Sones Bathroom Ventilation, and Exhaust Fan
- 2.0 sones super quiet performance. Silent-Clever Technology
- Mounting opening: 10.5" x 10.5". Height: 8". Stainless steel 6" duct collar
- Ventilating area for bathroom space up to 200 sq-ft
- HVI 2100-certified,and Energy Star Approved. Quality & performance assurance.
Although the BV Ultra-Quiet Bathroom Fan has an average CFM value of 200 (some high CFM fans have 350), it can still be relied upon to ventilate small areas quite well.
It can maintain the air quality of spaces that measure up to 200 square feet by effectively sucking excess humidity and bad odors that are found in bathrooms.
Additionally, the ventilation fan requires a small opening on the ceiling that measures 10.5 inches by 10. Inches. Some large fans require large cuttings or even 15 by 15 inches.
Cutting the small opening makes it very easy for the grilles to cover the ventilation fan completely and maintain the beauty of your bathroom ceiling.
Mounting this fan should not be a problem if you understand the basics of installing fans on ceilings or bathrooms. The suspension brackets are supposed to be used as extensions when mounting the ventilation fan on the wall of your bathroom. Some people may find the entire process very time-consuming and technical.
- It causes minimal distraction because of a low sones score of only 2.0
- The housing has been built to withstand excess moisture and other environmental conditions and keep the motor safe for long
- The inclusion of the dampers helps the fan to be more efficient in consuming energy by preventing backdrafts
- The installation and mounting procedures are long
6. Broan-Nutone 504 Exhaust Fan
- VERSATILE FAN: Exhaust fan helps eliminate , tobacco smoke, and cooking odors. The galvanized steel house installs easily between ceiling joists for use wherever you need it most
- EFFICIENT: Operates on 330 CFM and 8.0 Sones to ensure high-quality performance
- EASY INSTALLATION: Includes steel mounting brackets with keyhole slots for a fast and easy installation
- DECORATIVE: Paintable polymeric grilles allow you to ensure the fan is cohesive with your existing decor
- SAFE: This 10" fan is ENERGY STAR qualified and HVI certified to ensure safe use for years to come
The Broan-Nutone 504 Exhaust Fan can be a great companion for collecting and removing all the bad odors and excess humidity in your house. The grilles are effective at sucking in all unwanted odors from the kitchen and the bathroom and directing them outside through the duct.
Also, when you need the house to be warm, this ventilation fan can suck warm air that accumulates near the ceiling and distribute it across all the rooms in the house. It is a multipurpose fan that you would want to have in your house at all times.
The installation process is straightforward if you understand a thing or two about such fans. The mounting brackets and keyhole strokes are supposed to make the mounting process very easy to complete.
The main drawback of this ventilation fan is that its level of loudness is high. Some high-performance bathroom fans with CFM scores of over 300 have sones scores of less than 3.0.
- The polymeric grills can be painted to match the color of your walls
- Great performance because of the excellent airflow capability of 350CFM
- Low footprint means that you do not have to make big cuts on your ceiling during installation
- The loudness level of 6.5 sones higher than that of the majority of bathroom exhaust fans that are marketed as high-performance brands