What Is Bathroom Fan Sound Rating?

There’s nothing like unwinding in your bathtub after a long day at work. The bathroom is an excellent place to relax, though it also serves as the breeding ground for mildew and odor. An exhaust fan helps reduce significant moisture in bathrooms, but it can also be a nuisance if it’s too noisy.

Bathroom fan sound rating is a sound level rating given to bathroom fans and measured in sones. Sones is a numerical representation of how loud or quiet appliances are; the lower the number, the less noise you’ll hear. Quiet bathroom fans have a sound level rating between 0.3 to 0.9 sones.

Read on to learn more about bathroom fan sound ratings. This article will explore how a fan’s noise level is measured and discuss other qualities you should consider before buying one.

What Is a Sone?

A sone is a unit of measurement for sound, conceived in 1936 by Stanley Smith Stevens. Unlike decibels which measure loudness based on sound pressure level, a sone measures sound based on how the listener perceives it.

One sone is equivalent to a tone at 1kHz played at 40dB (decibels), which is how loud a refrigerator’s hum is. Sones are linear, so four sones will be twice as loud as two.

The table below should give you a better idea of how sones relate to decibel ratings and everyday sounds:

Sones	Decibels	Sound
0.29	10	Normal breathing
1.15	30	Whisper
9.2	60	Conversation
18.4	70	Washing machine
36.8	80	City traffic
104.3	95	Motorcycle

Read: Why Nutone Bathroom Fan And Light Stopped Working? – Troubleshooting Guide

Why a Bathroom Fan’s Sone Rating Matters?

The bathroom doesn’t only serve as a place to answer the call of nature and keep yourself clean, it’s also the ideal spot to get some alone time, to gather your thoughts, or clear your mind. So, the last thing you want is a noisy bathroom. Just imagine trying to study in a library that’s full of noise.

When buying an appliance, pay attention to its sone rating, especially if you plan on using it in your bedroom or bathroom. Bathroom fans have sone ratings that range from 0.3 to 6.0 sones. A bathroom fan with a sone rating above 1.0 would be considered annoying to some people.

Why You Need a Fan in Your Bathroom?

One of the best places to find serenity is in the comfort of your own home. Taking a dip in your bathtub is the perfect escape after a hard day’s work. So, keeping your bathroom clean and quiet is crucial to get your much-deserved tranquility.

No matter how cozy your bathroom is, it’s a hotbed for mold and fungus due to the moisture and heat that’s constantly present there. Molds proliferate by producing microscopic reproductive cells called mold spores. The humidity in the bathroom creates an ideal environment for mold spores to spread and grow.

Unless you take your showers in front of an open window, the lack of ventilation will increase and prolong the humidity in the bathroom. This humid environment is sustained each time you use warm water.

Installing an exhaust fan will significantly reduce the moisture in your bathroom and considerably lessen the tendency for mold to spread.  There are numerous advantages of having a fan installed in your bathroom.

Some of the benefits include:

• Quickly dissipating foul odors.
• Conveniently getting rid of steam and foggy mirrors.
• Improving the quality of air and reducing airborne contaminants from cleaning agents.
• Preventing water damage to bathroom surfaces.

Having an exhaust fan installed in your bathroom is crucial to keeping it well maintained and sanitary.

Read: How To Fix Samsung Refrigerator Fan Noise? – Troubleshooting Guide

How To Choose the Right Fan?

Many consumers can mistake choosing an exhaust fan based on price, availability, and maybe even aesthetic design. But for a fan to serve its purpose effectively, there are some technical qualities that buyers should not overlook.

The Fan’s Noise Level

When choosing an exhaust fan for your bathroom, you obviously would want one that will be quiet enough not to be annoying while in the bathroom. Since bathrooms are usually confined, sealed spaces, the reverberations from the walls amplify the softest sounds.

Earlier, we discussed sone ratings and how fans with lower sone ratings are quieter and less intrusive. And as much as you should select a fan with a low sone rating, it’s equally important to pick one that will adequately perform its primary function of removing moisture from your bathroom.

So, the idea is to choose a fan with a low sone rating that suits your budget, bathroom size, and installation requirements.

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The Fan’s Cubic Feet Per Minute (CFM) Rating

An exhaust fan’s primary purpose is to move hot and humid air out of a confined area. Hence, its airflow capability should conform to the size of the room.  Fortunately, fans have a CFM rating, which measures the volume of air they move every minute.

According to the Home Ventilating Institute, every square foot in your bathroom requires 1 CFM.  Bathrooms over 100 square feet should add 50 CFM for every toilet and shower.

It would be fair to assume that smaller, less powerful fans have low CFMs. And generally speaking, fans with low CFMs also have low sone ratings. However, neither statements are absolute since many factors affect a fan’s CFM.

The elements below each significantly impact a fan’s CFM:

• Fan speed. A fan’s maximum RPM (revolutions per minute), or how many times the blades complete a full rotation per minute.
• Blade size. The surface area of the blade.
• Blade design. The curve and angle of the blade.

Most exhaust fans with a CFM of 110 have sone ratings of 1.0 to 1.5. If you need a fan with a high CFM but can’t find one with an acceptable sone rating, you will need to take separate measures to lower the sone output.

You can reduce a fan’s noise by doing the following:

• Mount the fan on softer material.
• Insulate the duct.
• Install sound deadening materials.

Read: LG Microwave Fan Won’t Turn Off – Troubleshooting Guide

The Fan Type and Installation Method

Another vital consideration is what type of exhaust fan you should get and the installation method associated with each one.

Below are the different types of bathroom exhaust fans:

• Ceiling mounted fans. Integrated into the ceiling and pushes air out through the roof or attic.
• Wall-mounted fans. Mounted on the wall and pushes air directly outside the house.
• Inline fans. Fan is installed remotely (in another room) and sucks air through ducts connected to the bathroom.

Avoid having the exhaust fan move dissipate air by directing it to the attic or the space between ceiling joists. Redirecting the air from the bathroom to another part of your home will only cause mold and moisture to build up elsewhere.

It’s always advisable to use ducts to direct air outside the house. You can use duct adapters for ceiling or wall-mounted fans.

Read: Bosch Fridge-Freezer Fan Is Not Working

The Fan’s Efficiency

How much energy a bathroom fan consumes should not be overlooked. A fan that’s easy on your budget at the onset may end up costing you an arm and a leg in electricity bills.

Look for an exhaust fan that’s Energy Star Certified since it uses up to 70% less energy than non-certified fans. Energy Star Certified Products comply with stringent efficiency standards set by the US Environmental Protection Agency or the US Department of Energy.

The Fan’s Features

You should also consider a fan’s features before making a purchase. Some bathroom fans come with nifty features like built-in lights and heaters.

Smart fans have humidity or motion sensors that automatically switch the fan on and off as needed. Given the heftier price tag, it may seem like an added expense, but the lower energy consumption may save you more money in the long run.

The Broan-NuTone SPK110 Bathroom Exhaust Fan (available on Amazon.com) has a CFM of 110 and a sone rating of 1.0, making it capable of covering over 100 square meters (1,076 square feet) without being noisy. It also has a built-in BlueTooth speaker so you can enjoy music and sing along while taking a bath.

Final Thoughts

Exhaust fans play a significant role in reducing humidity and odor in your bathroom. All fans have a sone rating which determines how much noise they make during operation. But, you also have to consider other factors (like CFM) because as crucial as it is to purchase a quiet fan, you have to ensure that it can adequately perform its primary function.