Bathroom Exhaust Fan Size Chart

Bathroom Exhaust Fan Size Chart

If you are doing a bathroom renovation then it's time to look at replacing your existing exhaust fan. After all, changing the layout and size of your bathroom means that your old fan may not be up to snuff anymore. It could also be that your old fan may be making a lot of noise and not working as well as it used to. Whatever the situation, shopping for a new bathroom exhaust fan can be exhausting.

But it doesn't have to be. That's where this buying guide comes in. We are going to review ten of the best bathroom fans on Amazon. After the exhaust fan reviews, we're going to talk about what you should be looking for in a bathroom exhaust fan with our buying guide. The buying guide will cover things like what features you should be looking for how to appropriately size an exhaust fan and some considerations in installation.

Bathroom Exhaust Fans Reviews

The Winner

Air King BFQ 140

• Noise Level: 4.0 Sones
• CFM Rating: 120
• White color
• 1 year warranty

This bathroom exhaust fan from Air King has a CFM rating of 120, making it perfect for larger bathrooms or as a permanent exhaust fan to promote healthy air circulation in your home. It is a bit noisier, generating 4.0 sones during operation, however. As a comparison, that's roughly as loud as a car idling from about 33 feet away. This fan has an 8.5 x 9.1 installation size for the housing with a 4.75-inch height. The exterior grille is a white plastic that measures 10 x 10 inches and is held in place with torsion springs.

Installing this fan is easily accomplished thanks to the included lock-in bracket included with the kit. You mount the fan directly to a joist in any ceiling with at least 6 inches of clearance. This fan is rated for ceiling insulated up to an R-40 factor as well. If you like, you can also install this fan on the wall with a rough-in opening of 8.5 x 9.1 inches, provided the fan is at least 8 feet above the floor.

This fan features a one-piece plastic blower wheel with 48 fins connected to a permanently lubricated 4-pole motor. The motor has built-in thermal protection to prevent it from running too hot. The fan housing is made of flame retardant ABS as well. The duct color is meant for a 4-inch duct connection and includes a back draft damper to ensure quiet and smooth operation. The motor draws 0.75 amps from a standard 120-volt line. If installing above a shower or tub, use a GFCI protected branch circuit. This fan has a one-year limited warranty as well.

Read Full Review: Air King BFQ 140 Bathroom Exhaust Fan

Features:

• Dimensions: 8-1/2 x 9-1/16 x 4-3/4 inch Installation
  • Grille: 10 x 10 Inch
• Duct Connection Size: 4 Inch
• CFM Rating: 120
• Noise Level: 4.0 Sones
• Electrical Requirement: 68 Watts, 120 Volt GFCI, 0.8 Amps
• Light Kit: None
• Heating Element: None
• Color: White or Cream
• Warranty: One Year Limited

Best Performance

Broan-NuTone 9093WH

• Noise Level: 3.5 Sones
• CFM Rating: 70 CFM
• Heating Element: 1500 Watts
• 1 year warranty

This Broan-NuTone fan is one of the top-rated bathroom fans on Amazon. It features an integrated light as well as a built-in heater. It is a little different from the other fans in our review section in that the grill and shape are round. It has a centrifugal blower wheel that is able to clear 70 CFM. This provides adequate ventilation for bathrooms up to 100 square feet. The fan is 13.25 inches in diameter and 7.5 inches tall. The exterior Grill is 15-3/8 inches in diameter which gives you about 1-inch clearance around the entire circumference.

The fan can be installed between joists using the included expansion hanger bars. The bars can reach up to 24 in. Additionally, you can use mounting brackets that can be adjusted for up to 3/4 inch plaster. The fan works with a 4 inch round duct so vented air has plenty of room to escape. When it comes to noise level, this fan is early quiet generating 3.5 sones during operation.

This bathroom exhaust fan also features a 100-watt incandescent light bulb fixture as well as a 7 watch night light. The main light is not included in the kit but the 7 watt light is. The heater for this combination exhaust fan provides 1500 watts of heat. It requires a 20 amp dedicated branch circuit with a 120-volt line. The fan Grill is white so that it will match pretty much any decor in your bathroom. This fan has a one-year limited warranty from the manufacturer which covers manufacturer defects and parts.

Read Full Review: Broan-NuTone 9093WH Bathroom Exhaust Fan

Features:

• Dimensions: 13.25 Inch Diameter x 7.5 Inch Height for Installation
  • Grille: 15-3/8 inch diameter
• Weight: 17 Pounds
• Duct Connection Size: 4 inches Round
• CFM Rating: 70 CFM
• Noise Level: 3.5 Sones
• Electrical Requirement: 120 V / 20 Amp / 1717 Watts
• Light Kit: 100 Watt Incandescent / 7 Watt Nightlight
• Heating Element: 1500 Watts
• Color: White
• Warranty: One Year

Best Value

Broan-NuTone 688

• Noise Level: 4.0 Sones
• CFM Rating: 50
• 120 Volt GFCI
• 1 year warranty

This bathroom exhaust fan from Broan Nutone offers 50 cubic feet per minute of air circulation. That makes this fan suitable for rooms up to 45 square feet in size. The housing dimensions for this fan are 7.25 by 7.5 in with a 3-5/8 inch height. The grill is made of white polymer to blend well with nearly every Decor. It measures 9 in by 9.25 in. It installs on to the fan housing with a torsion spring with no tools required. You can get a metal Grill. This is available for purchase separately from the base fan kit.

The ventilation motor for this exhaust fan is a permanently lubricated polymeric blower wheel. The motor assembly snaps in and out to allow for easy cleaning. The fan can be used as a traditional bath fan for removing humidity and odors as needed, or you can run it continuously to help cycle are throughout the home. This fan connects to a 3-inch duct.

This exhaust fan is a great choice for someone who is looking for a No-Frills inexpensive option for their bathroom. With its ease of installation and ability to be installed with a standard 120-volt GFCI and a one-year manufacturer's warranty, you can trust that this Broan Nutone model will meet your needs for an exhaust fan or something to keep your air circulating.

Read Full Review: Broan-NuTone 688 Bathroom Exhaust Fan

Features:

• Dimensions: 7-1/4 x 7-1/4 x 3-5/8 inches
  • Grille 9 x 9-1/4 inches
• Duct Connection Size: 3 inch
• CFM Rating: 50
• Noise Level: 4.0 Sones
• Electrical Requirement: 120 Volt GFCI
• Light Kit: No
• Heating Element: No
• Color: White
• Warranty: One Year Limited

VERSATILE - Heater, Fan, and Light Combo

Broan-NuTone 665RP

• Noise Level: 4.0 Sones
• CFM Rating: 70
• White color
• 1 year warranty
  

This Broan Nutone ventilation fan is able to move 70 CFM while generating 4.0 sones. The housing is rectangular measuring 14 5/8 in by 7 and 7/8 in with a height of 5 and 5/8 in. The exterior Grill is white plastic and measures 9 7/8 inches by 16 in 1/4 inch. The fan housing is made of cold-rolled galvanized Steel, while the grill is made of white plastic. This band attaches to a 4in duct via a long plastic adapter with a backdraft damper.

Installing this exhaust fan with the included 16 inch to 24 inch hanger bars is fairly simple provided you follow the included instructions carefully. Remember that all electrical wiring should be done by a qualified person to maintain code adherence. Because this fan does have a 1300 watt heater, it does require a 20 amp dedicated branch circuit. The unit itself post 12.5 amps to power the fan, the heater, and the 100-watt incandescent bulb. The heating element on this fan is an open coil nickel-chromium variety.

The fan itself is a centrifugal impeller connected to a thermally protected motor. If you have other construction requirements, NuTone does have a complete line of accessories that will help you. However, with a built-in junction box, this is generally not needed. This unit is not designed to be installed over a bathtub or in a shower stall. It does have a one-year limited warranty as well.

Read Full Review: Broan-NuTone 665RP Bathroom Exhaust Fan

Features:

• Dimensions: 14-5/8 x 7-7/8 x 5-5/8 inch Installation
  • Grille: 9-7/8 x 16-1/4 Inches
• Duct Connection Size: 4 Inches
• CFM Rating: 70
• Noise Level: 4.0 Sones
• Electrical Requirement: 120 Volt, 12.5 Amp, Requires a Dedicated 20A Branch Circuit
• Light Kit: 100 Watts
• Heating Element: 1300 Watts
• Color: White
• Warranty: One Year Limited

Runner Up - VERSATILE

Broan-NuTone 100HL

• Noise Level: 2.0 Sone
• CFM Rating: 100
• White color
• 1 year warranty
  

This bathroom exhaust fan from Broan-NuTone scored quite well in overall bathroom vent fan ratings. It has a directionally adjustable fan with a heater and incandescent light kit. It is also available with a fluorescent light kit for an additional cost. This fan is able to move 100 CFM of air, operating at 2.0 sones. That makes a good bathroom fan for rooms that are up to 90 square feet in size. This fan is meant to work with a 4-inch duct.

Installing this exhaust fan is quite simple. It is designed to fit into a 2 x 6 ceiling construction. If necessary, the kit includes 24-inch adjustable hanger bars for wider joist separation. The insulation housing has dimensions of 16 x 10 and 1/4 inches. It also has a height of 5 and 7 / 8 inches. The exterior Grill is 17.5 by 11.5 in and is made of white plastic. One side of the exterior Grill has an adjustable circular Louver which helps you to direct heat wherever you need it. This fan does require a 20 amp dedicated branch circuit for operation. Again, it is not recommended to install this above a shower or bathtub.

If you like, you can replace the hundred Watt incandescent light with a 27 Watt fluorescent lamp. The motor for the fan is permanently lubricated and require zero maintenance. You still want to occasionally clean it, but there is no need for internal maintenance. This exhaust fan is not just for bathrooms. They can also be installed in any room where you want to remove stale air.

Read Full Review:Broan-NuTone 100HL Bathroom Exhaust Fan

Features:

• Dimensions: 16 x 10-1/4 x 5-7/8 Inch Installation
  • Grille: 17-1/2 x 11-1/2 Inch
• Duct Connection Size: 4 Inch
• CFM Rating: 100
• Noise Level: 2.0 Sone
• Electrical Requirement: 70.2 Watt, 120 Volt, 14.5 Amp, Requires Dedicated 20A Branch Circuit
• Light Kit: 100 Watt Incandescent
• Heating Element: 1500 Watt
• Color: White
• Warranty: One Year Limited

Ideal for New Construction and Renovations

Panasonic FV-05-11VKS2

• Noise Level: 0.3 Sones
• CFM Rating: 30 to 110
• Duct Connection Size: 4 or 6 inch
• 1 year warranty

This Panasonic bathroom ventilation fan is extremely quiet, generating only 0.3 sounds during operation. The square fan is 10.5 inches square by 7.4 inches tall during installation. The outside grill is 13 x 13 inches, giving you a 1.25-inch lip around the perimeter of the fan. This fan has a variable Speed Motor and they allow you to select an air movement rate from 30 CFM to 110 CFM. This means that you can place is Fan in any number of bathrooms depending on their size and your need.

The exhaust fan is fast and easy to install. It works with both 4-inch and 6-inch ducts so you can be flexible and your placement and Design. Fast installation brackets allow you to position this fan exactly where you need it to be. The fan's housing is made of 26 gauge zinc aluminum magnesium (ZAM) and fits into a 2 by 8 space in your ceiling joists when installing, it requires a 120-volt GFCI placement with a draw of 20 watts.

While this fan does not have a light kit or a heating element, it does have a unique plug-and-play module system. This system allows you to add features such as a Smart Action motion sensor which automatically turns the fan on and increases its RPM when it senses somebody entering the bathroom. Another audible feature is a condensation sensor. This fan has one of the best warranties of all of our reviewed bathroom exhaust fans with six years on the motor and three years on component parts.

Read Full Review: Panasonic FV-05-11VKS2 WhisperGreen Bathroom Ventilation Fan

Features:

• Dimensions: 10.5 x 10.5 x 7.4 inches for installation
  • Grille: 13 x 13 inches
• Duct Connection Size: 4 or 6 inch
• CFM Rating: 30 to 110
• Noise Level: 0.3 Sones
• Electrical Requirement: 20 Watts, 120 Volt GFCI
• Light Kit: None
• Heating Element: None
• Color: White
• Warranty: 6 Year Motor, 3 Year Parts

Best Quiet Option

Broan-NuTone AE80B

• Noise Level: 1.5 Sones
• CFM Rating: 80 CFM
• White color
• 1 year warranty
  

This bathroom exhaust fan from Broan Nutone is energy STAR certified. This fan gives you the ability to install it completely from the bathroom side without having to venture into the attic or the crawl space. The fan is 9.25 by 10 in with a 5.75 in Height. The exterior Grill is 11.5 x 12 in. The fan connects to a 4-inch polymeric duct connector and allows for installation with 2 x 6 joist spacing.

This fan generates 80 cubic feet of air movement per minute while generating only 1.5 sones of noise. The stand can be installed in the ceiling or along the wall. Keep in mind that if you do install the spin on a wall and must be mounted at least eight feet or more above the floor. This exhaust fan comes with a 26 gauge galvanized steel construction housing.

Additionally, with the special TruSeal technology, this fan can reduce air leakage by up to 50% compared to other models. It can be installed over a bathtub or a shower with a GFCI circuit.

This fan draws 24.7 Watts on a 120-volt line and requires 0.3 amps. It does not include a light kit or a heating element, but it does function as a simple and efficient exhaust fan. The fan is a permanently lubricated centrifugal blower wheel, and can be mounted and ceilings with up to a 7/12 pitch. This bathroom exhaust fan comes with a one-year limited warranty.

Read Full Review: Broan-NuTone AE80B InVent Bathroom Exhaust Fan

Features:

• Dimensions: 9.25 x 10 x 5.75 inches for installation
  • Grille: 11.5 x 12 inches
• Duct Connection Size: 4 inches
• CFM Rating: 80 CFM
• Noise Level: 1.5 Sones
• Electrical Requirement: 24.7 Watts, 120 Volt GFCI, 0.3 Amps
• Light Kit: None
• Heating Element: None
• Color: White
• Warranty: One Year Limited

Runner Up - Super Quiet

BV BF-01

• Super quiet performance
• Mounting opening: 9.25" x 9.0"
• Space up to 90 sq-ft
• 1 year warranty

This fan has a housing dimension of 9 by 9 in with a height of 7.6 in. It has an airflow rating of 90 CFM with an extremely quiet noise level of 0.8 sones. It weighs just over 9 pounds and is extremely easy to install on your own. The fan connects to a 4-inch duct. The exterior grille dimensions are 12.62 inches square. The fan grille is white and made of plastic so you can paint it to match your decor or leave it white.

When it comes to installing this bathroom exhaust fan, it comes with a set of suspension brackets as well as the screws necessary to mount this between the ceiling joists. If you are mounting this into an existing ceiling, you can install the duct into position so the housing lined up correctly and then use included screws to secure the duct connector with the exhaust. The suspension brackets included are 10 and 1/16 inches and 7 7/8 inches in length.

This exhaust fan features a heavy-duty motor with lifetime lubrication and thermal protection. The fan is also UL certified and HVI 2100 certified. It pulls 24 watts and requires a 120-volt line. It is recommended that if you install this over a shower or open bathtub that you use a GFCI circuit. This fan has a one-year limited warranty.

Read Full Review: BV BF-01 Bathroom Exhaust Fan

Features:

• Dimensions: 9 x 9 x 7-5/8 inches installation
  • Grille: 12-5/8 x 12-5/8 inches
• Duct Connection Size: 4 inches
• CFM Rating: 90
• Noise Level: 0.8 Sones
• Electrical Requirement: 24 Watts, 120 Volt GFCI
• Light Kit: No
• Heating Element: No
• Color: White
• Warranty: One Year Limited

Suitable for 120 sq. ft. Room

Hauslane BF200

• Noise Level: 1.2 Sones
• CFM Rating: 120
• 6 Watt LED Light Kit
• 2 year warranty

This large ceiling fan is able to remove 120 cubic feet per minute of bathroom exhaust. The fan operates at 1007 RPMs but only generates 1.2 sones. This low level of noise means that even while operating at its maximum capacity, you will barely hear it. This man is perfect for large bathrooms measuring up to 120 square feet. It requires a 4in duct connection. The fan has a 9 by 9 in insulation size with a 7 and 3/4 in installation height. The grill measures 9 1/8 by 9 1/8 inches. The exhaust fan weighs 10 pounds which means that it is easily mountable between joists in your ceiling.

This exhaust fan includes an integrated 6-watt light panel constructed with LEDs. It should be noted that if any of the lights burn out, you have to get a new panel directly from Hauslane. The replacement panel is fairly inexpensive, and the LEDs should last for at least ten years of normal use.

The exhaust fan does not include a heating system, however. This fan pulls 45 watts of power and can be wired into an existing 120 line and connected to a wall switch. If you are installing this above a shower or open tub, you should use a GFCI circuit for your own safety.

This vent fan includes a double hanging bar system for installation which means you aren't constrained in placement by where your joists are. The light panel is rated to emit light along the 5000K spectrum, which is a softer neutral light meant to simulate the daylight spectrum. This bathroom exhaust fan has a two-year limited warranty that protects the purchaser against manufacturer defects.

Read Full Review: Hauslane BF200 Bathroom Exhaust Fan

Features:

• Dimensions: 9 x 9 x 7-3/4 inch Installation
  • Grille: 9-1/8 x 9-1/8 inches
• Weight: 10 pounds
• Duct Connection Size: 4 inches
• CFM Rating: 120
• Noise Level: 1.2 Sones
• Electrical Requirement: 120 volt GFCI
• Light Kit: 6 Watt LED
• Heating Element: None
• Color: White
• Warranty: Two Year Limited

Other Great Option

BV BF-03

• Noise Level: 2.0 Sones
• CFM Rating: 150
• White color
• 2 year warranty

This exceptionally quiet bathroom exhaust fan can remove 150 CFM of air while only generating 2.0 sones. This makes it great for larger bathrooms of over 120 cubic feet in size or other rooms where you desire venting and exhaust. This bathroom exhaust fan has a housing that is 10.31 inches square with an 8.07 inch height. It weighs a modest 13.36 lb and has an exterior Grill size of 13.38 inches square.

When installing this bathroom exhaust fan you can mount it one of three ways. You can either close mount it without using the suspension brackets. You can also mount it using the suspension brackets. This kit includes two sets of suspension brackets. One set is 10 1/16 inches in length and the other is 7 7/8 inches in length. The last where you can mount this fan is by installing it into an existing ceiling. If installing into an existing ceiling, you should remove the duct connector first. Once that is installed correctly and position then install the housing. This game can connect to either a 4in or a 6in duct.

This bathroom exhaust fan does not feature a light kid or a heater. However, even without those, the extremely quiet operation for the high volume of air removal makes it an attractive choice. The fan pulls 42 Watts on a standard 120-volt line. Remember that if you install this fan above a shower or bathtub, you should install it on a GFCI protected branch circuit for your protection.

Read Full Review: BV BF-03 Bathroom Exhaust Fan

Features:

• Dimensions: 10.31 x 10.31 x 8.07 Inch Installation
  • Grille: 13-3/8 x 13-3/8 inch
• Duct Connection Size: 4 Inches
• CFM Rating: 150
• Noise Level: 2.0 Sones
• Electrical Requirement: 42 Watt, 120 Volt GFCI
• Light Kit: None
• Heating Element: None
• Color: White
• Warranty: Two Year Limited

Bathroom Exhaust Fans Buying Guide

Now that you've read our bathroom fan reviews, it's time to delve into the buying guide so you can make sure you get the best bathroom fan for your lifestyle. First, we'll go over a little bit of what bathroom exhaust fans do and then we will cover the features that are most pertinent for your shopping. Finally, we will help you calculate what size of exhaust fan you need.

What Do Bathroom Exhaust Fans Do?

It seems simple to figure out what a bathroom exhaust fan does. After all, it says right in the name. At their most basic, bathroom exhaust fans take humid air and expel it to the outside so that condensation and moisture do not build up in your bathroom. Moisture buildup in your bathroom can lead to mildew, mold, and other health hazards. Bathroom exhaust fans also help in venting odors, as well as keeping fresh air circulating through your home.

However, bathroom exhaust fans are not just for bathrooms. You can install a bathroom exhaust fan wherever you like. For example, if you are a maker and work with 3D printing or laser engraving, you know the importance of proper venting. Expelling VOCs and other gases is extremely important for safety. If you have a workshop where you paint or sand, then encouraging natural air circulation can keep your lungs and brain Clear.

8 Features to Think About When Buying Your Next Bathroom Exhaust Fan

When it comes to purchasing the perfect bathroom exhaust fan, there are a lot of options in features to keep in mind. While this is not an exhaustive list by any means, these eight considerations are things that you should definitely be thinking about while shopping.

1. Wall or Ceiling Mount

While most people think of installing a bathroom exhaust fan on the ceiling, you can also install them on the wall. It is worth considering wall installation, especially if your ceiling has a high insulation R-value. In some cases, depending on the type of bathroom exhaust fan too much insulation can cause a fire hazard. Just keep in mind that if you do decide to install your exhaust fan along the wall, it should be at least 8 ft above the floor.

2. Noise Level

Exhaust fans generate noise. However, while you may be used to thinking of measuring noises in terms of decibels, fans are rated in sones. The difference is subtle but it's very distinct. Without getting too technical, a decibel measures air pressure. A Sone, however, measures the perception of how loud a sound is.

In real-world terms, every time you double the Sone value you are doubling the loudness. So, a 4.0 Sone fan is 4 times as loud as a 1.0 Sone fan. However, an 8 sone fan is only three times as loud as a 1.0 sone fan. 4 measurements steak, a 1.0 Sone is about as loud as a quiet refrigerator in a quiet kitchen.

It's important to understand the sound rating system of fans so you understand what manufacturers are talking about when they advertise. There are some bathroom exhaust fans that are extremely quiet with fans that are below 0.3 sones. However, these exhaust fans are typically more expensive.

3. Exhaust Duct Size

When looking at bathroom exhaust fans, it's imperative that you compare the size of the exhaust port to your existing ductwork. The most common sizes are 4 and 6 inches. If you are investing in a high volume fan, you may find that the exhaust Port is 6in. If your existing ductwork is only four inches, it's recommended that you upgrade for increased efficiency. If you don't want to, you can't get adapters that will step down from 6in to 4in.

4. Electrical Needs

We have listed the electrical requirements of all of the fans that we have reviews for. It is imperative that you ensure that you adhere to those requirements when you are installing a new bathroom exhaust fan. You do not want to overload your circuits every time you turn your fan on. Additionally, if your new fan is able to be installed over the bathtub or in a shower stall, make sure that you use a GFCI protected branch circuit.

5. Installation Location

We touched briefly on installing an exhaust fan on the ceiling or the wall, but if you are looking to install an exhaust fan in another room, you can generally dispense with additional features such as a heater or a light kit. Think about where you plan on installing your new exhaust fan and if it is not in the bathroom, then consider the needs of whatever room you will be venting. Later on, we will discuss how to measure and appropriately-sized an exhaust fan.

6. Lighting

Having a lighting kit for your exhaust fan is a great option. It essentially kills two birds with one stone. You can remove the existing light and install the ceiling fan where it was, and seal over the location of the current fan. Some things to keep in mind when looking at light kits are the wattage and type of light that the fan kit text. If it takes a specialized bulb then you may want to check to ensure that there is a CFL or LED equivalent.

Upgrading from incandescent to CFL or LED can not only save you money on your light bill, but it will also save you from having to change the lightbulb as often. CFL bulbs are often rated for up to 10 years of normal operation while LED bulbs can last up to 15 years or longer.

7. Heating

Having a heater with your exhaust fan may seem a little decadent. However, it's actually a very nice feature to have in a lot of cases. Having a heater on your exhaust fan can help you save money in the mornings when you are going to be spending a lot of time in the bathroom.

Rather than turn on your Main Heating, you can leave your thermostat set low and turn the heater on in the bathroom. This will quickly and efficiently heat up that small space so you're not spending the money to warm up the rest of the house that you aren't going to be using. And let's be honest, it's also really nice to stay warm with an integrated heater when you're fresh out of the shower and drying off and getting dressed.

8. Other Accessories

Some manufacturers offer other accessories for your bathroom exhaust fan that are very nice to have. Here are a couple of accessories that have caught our eye.

• A motion detector installed into a bathroom ceiling fan Works in conjunction with a variable intensity fan. When the motion detector sense is it somebody is coming into the bathroom it turns the fan up. Likewise, if it doesn't detect anybody or any movement for a long period of time it turns the fan back down. If you like to continuously operate your exhaust fan to keep air circulating, this is a great option to help you save money.
• Moisture detectors work like motion detectors, except instead of sensing people moving around, it detects when the humidity in your bathroom goes above a certain point. This will protect your bathroom from water damage. In this case, it allows the fan to act almost like a dehumidifier.

What Size Exhaust Fan Do You Need? Calculating the CFM You Should Have

It's tempting to get the largest exhaust fan that you can afford or fit into your bathroom simply because it's the largest. After all, what could go wrong? However consider that while you are running the bathroom exhaust fan, you're pulling air from other parts of the house. If it's the dead of winter then you are pulling heat out of your home. And if it's in the middle of summer, you will do the same with air conditioning. It's far better to invest in a quieter or more efficient exhaust fan then one that pulls more CFM. That being said, here is how to appropriately-size the best exhaust fan for your room.

First, you need to determine the overall cubic footage of your room. For example, if your bathroom has an 8-foot ceiling and is 10 by 9, then your total cubic footage is 720 cubic feet. Next, you want to take this number and multiply it by 0.13. That gets your 93.6. Then you want to round up to the nearest ten, so in this case, you want a fan with a CFM rating of at least 100.
If you have a sloped ceiling or a vaulted ceiling, then take the average height at the wall and at the peak.

What Type of Ducts? Flexible or Rigid

When installing a new bathroom exhaust fan, you may wonder whether you should have flexible or rigid ductwork. There are pros and cons to each. In general, we will always recommend rigid ductwork oh, and here's why.

When your exhaust fan is working it is blowing air through your ducts. The less wind resistance there is, the more efficient your exhaust fan will work. Solid ductwork is smoother and allows for airflow to be faster and more efficient. Additionally, it usually has fewer 90 degree bends so the air gets to the outside faster and more smoothly.

Contrast this with flexible ductwork that has wire wrapped around the ductwork to hold it in shape. Those wires cause nooks and crannies to form which causes air to flow less efficiently. Additionally, ductwork can lay in weird directions and can sometimes take unnecessary turns in getting to where it needs to be. While rigid ductwork is going to be a little more expensive, it is worth it in terms of efficiency.

No matter which you choose, you should always keep some general rules of thumb in mind when running ductwork, especially for your bathroom.

• First, remember that the building code says that the total horizontal length of the vent cannot be greater than 75% of the vertical height of the vent. Essentially what this means is that if your bathroom exhaust fan's ductwork goes up 10 ft it cannot go to the side more than 7.5 ft. If the vertical height of your vent is less than 7.5 ft, you should be venting through the roof and not from the side anyway.
• Another thing to keep in mind is if you are using ductwork that goes through an unheated portion of your home or your home's crawl space or attic, then the ductwork needs to be insulated. This is to prevent condensation from building up in the ductwork which can cause a multitude of problems.

Maintenance and Care of Your Exhaust Fan

It's never fun to perform maintenance or clean your bathroom exhaust fan, but it is completely necessary. One key thing to look for is if you are looking at the fan, and you see dust, then you should get up there and take care of it. If you notice that it's taking a little longer for the steam to clear from your mirrors, that's another sign. Here we'll walk you through the basic steps of cleaning your bathroom exhaust fan.

First, you should check to see if you still have at least a little airflow going through your fan. One of the best ways to check if your bathroom exhaust fan is still working is to do the toilet paper test. First, take a small piece of toilet paper and hold it near your exhaust fan. This piece should be about the size of your thumbnail, so if you let go and it gets sucked up into the fan, it doesn't clog or cause damage. If you feel the paper being pulled from your fingers then your exhaust fan is still working. If you don't feel that, then you definitely need to clean your exhaust fan.

1. The next thing to do is to turn the fan off at the breaker. It doesn't matter if your fan has a dedicated branch or if it's part of your bathroom's entire circuit. Turn off the appropriate circuit breaker and label it with a note that warns other people not to turn it back on. You want to make sure the fan doesn't have power and that it won't get power while you're up there poking around. When you get back to the bathroom flip the switch so that the fan discharges all of the energy it may still have in its circuitry. This helps ensure that you don't get an unexpected shock when you start cleaning.
2. Next, use a sturdy stool or stepladder. Don't use a kitchen chair or a stack of boxes. Then remove all of your jewelry, including your rings. Your spouse will understand if you take off your wedding ring to clean the exhaust fan. If they don't, then you can Google ring related accidents that happen when people are working on ladders. It's not pretty and it should convince them you were right pretty quickly.
3. The next step is to remove the fan grill or cover. This is usually held on by metal clips. Just simply press them to the side and the cover should come off quite easily. Some fan grilles are held in by screws, however. If this is the case, unscrew them and put them in a safe place. An empty aspirin bottle works great for this. Close the lid on the screws while you're working so you don't knock the bottle over and lose them.
4. Wash the fan cover in warm soapy water and set it to the side. Make sure that it is completely dry before reinstalling. If you have the time, you can put it in your dishwasher. Just make sure to let it air dry and don't use the heated drying method or you can warp the cover.
5. Next, you need to disconnect the fan from the housing. This usually involves screws, so use another plastic baggie or pill bottle to hold those screws. Once you do that, you can vacuum inside the housing around the motor. Be careful when you do and use the soft brush attachment. This is the one that looks like a circle of bristles. When you're done, wipe the fan blades down with a soft damp cloth. If you like, we recommend using a disinfecting wipe like a Clorox or Lysol wet wipe. This not only removes dirt quickly but also cuts through any oil or residue.
6. After that, check the exhaust vents and the ductwork. Make sure that there's no buildup of moisture, mold, condensation, or anything. If there is, take the time to clean it. While you may not have the equipment to do a deep clean into the vents, anything is better than just leaving it there.
7. Once that's done, make sure everything is dry and that you haven't left any cleaning cloths in the vent. Then reconnect your fan to the housing, and replace the fan cover, using the screws if necessary. You can then safely turn the electricity back on, and use your fan as normal.

It's recommended that you clean your fan at least once every three months. Keeping up with it at this interval ensures that it will never get too dirty. Additionally, if you can, you should clean the ductwork every year. This is to prevent a buildup of dust, and any mold, or mildew that may be in there.

Bathroom Exhaust Fans Comparison Chart

Bathroom Exhaust Fans	CFM	Noise Level	Duct Connection Size	Weight	Rating
Broan-NuTone 9093WH	70 CFM	3.5 Sones	4 inches Round	17 Pounds	9
Panasonic FV-05-11VKS2 WhisperGreen	30 to 110	0.3 Sones	Size: 4 or 6 inches	11.8 pounds	8
Broan-NuTone AE80B InVent	80 CFM	1.5 Sones	4 inches	8 pounds	9
Broan-NuTone 688	50	4.0 Sones	3 inches	3 pounds	9
BV BF-01	90	0.8 Sones	4 inches	10.7 pounds	9
Hauslane BF200	120	1.2 Sones	4 inches	10 pounds	8
Air King BFQ 140	120	4.0 Sones	4 inches	5 pounds	8
BV BF-03	150	2.0 Sones	4 Inches	13.25 pounds	8
Broan-NuTone 665RP	70	4.0 Sones	4 Inches	10 pounds	8

Conclusion

By now, we hope that you have a firm grasp on the issues surrounding choosing a bathroom exhaust fan. We hope that your shopping is as painless as possible. If you need any further assistance please feel free to reach out and contact us. Our experts are standing by to help you. We hope that our unbiased reviews and end up buying guide were able to help you determine the best bathroom exhaust fan for your needs and we are glad that you let us help.

Charles Jasper is the owner and main author of Home Climate Center. He has a degree in Engineering and 20 years experience on working on HVAC systems. He has a passion for everything related to home improvement and loves to travel. When he is not working, you might find Jasper working on projects around the house or organizing a camping trip.

Bathroom Exhaust Fan Size Chart

Source: https://homeclimatecenter.com/best-bathroom-exhaust-fans-reviews/