Did you know that the relaxing shower you have after a tiring day might actually also have a detrimental effect on your home? How? So much of humidity and vapor build-up in an enclosed space can lead to mold and mildew growth. This can further damage your home structure — including the walls, ceiling, and drywall. Hence, in order to prevent this, you need to install one important feature in your bathroom — bathroom exhaust fans. This small component shall protect your building by removing health-hazardous agents such as extra moisture, mold spores, and bad odors. Therefore, if your bathroom smells musty or does not have a fan yet, you should consider installing one in your next bathroom remodel.

What Are Bathroom Exhaust Fans?

A bathroom exhaust fan is a mechanically operated device that is connected to the exterior via duct pipes. It draws in moisture, impurities, small particles, and odors and releases them outside. The entire process ensures that your interior air is pure, dry, fresh, and clean.

How Do Bathroom Exhaust Fans Operate?

A vent fan is connected to your normal electrical circuit and is operated via a wall switch. When you turn on the switch, the fan shall run to draw in air and transfer it out via a hose/duct into an opening located at the roof or sidewall of your house. This equipment also features a louvered cover plate at the endpoint — which closes off the duct when it is not in use.

So, What Are the Factors That You Should Consider Before Installing Bathroom Exhaust Fans?

With emerging technologies and smart manufacturing techniques, bathroom exhaust fans, today, are available in various efficient and functional models. However, with so many features and specifications, sometimes it might become a daunting task for a shopper to choose the perfect type for his home. Therefore, if you know the important factors that you should consider before buying one, then the job becomes much easier. So, here, we shall outline the major aspects which you are required to keep in mind before making the final purchase.

Venting Mechanism

This is the most important factor. You should always go for a bathroom fan that comes with the option to connect its ducts so that moisture is released outside. In many cases, it so happens that the exhaust air is simply expelled to the openings between the ceiling joists or into an attic. Because of this, water collects in those dark, dingy places — leading to mold growth — and damage to your property.

Efficient venting will ensure that your fan sucks in maximum amounts of indoor air and transfers the heat outdoors. Although this is ideal for summer, during winter, it might result in your home becoming colder. In such a case, go for heat-exchange ventilator fan. These models shall suck in heated air and replace it with heated-up, fresh air from the outside.

Air Flow Capacity

The usual measurement of air movement is calculated in cubic feet per minute (CFM). According to the Home Ventilation Institute, the recommended ventilation rate should be eight air changes per hour — which converts to 1 CFM rating per square foot of bathroom area. For example, if your bathroom is of 100 square feet, then you should ideally get bath fans with a rating of 100 CFM. HVI gives the following specifications for air flow capacity according to your bathroom size, which will ensure maximum energy efficiency:

  • Less than 50 square feet: Minimum 50 CFM
  • 50-100 square feet: 1 CFM per square foot of floor space
  • Higher than 100 square feet: Add the CFM requirement for each fixture (such as — 50 CFM each for the toilet, shower, and bathtub and 100 CFM for a jetted tub)

Energy Efficiency

energy plan

Check for the Energy Star label on the model that you are planning to buy. This certification should come from authentic associations such as the Home Ventilating Institute or the Air Movement and Control Association. Models with Energy Star ratings consume 60% less energy than other ordinary models. You can also go for fans which feature motors that operate with minimal noise. Most of these motors consume very less energy.

As bathroom exhaust fans form part of HVAC systems, look at the required building codes in your vicinity. Several areas may require residents to install energy-efficient appliances — when any new construction is taking place or when a major bathroom renovation is in the pipeline — in order to comply with the set specifications.

Read more: Make your home energy efficient

Noise Levels

The unit for measuring the noise level of bathroom fans is sones. In order to ensure a quiet fan operation, get a model which features a rating of 1.0 sones or less.

Read more: Knocking noise in house walls

Bathroom Exhaust Fan Types

As per your need, you can get a standalone model that comes with only the ventilating fan. You can also go for a combination unit — which shall incorporate a fan, a light fixture, and maybe, a heat lamp. If your budget permits, you can even opt for luxurious units such as models with Bluetooth and speakers — to enable you to stream music whenever you are in the mood.

Read more: Bathroom Exhaust Fan Installation

Other Smart Features

Several upcoming models are now equipped with numerous smart features. Check out a few of the notable ones below:

Fan Lighting

This is a type of overhead lighting that can be turned on via motion sensors or switches. There are also night lights installed in certain models which can help you to navigate in the dark.

Motion sensor activation

These fans are designed to automatically start as soon as someone enters the bathroom.

Humidity sensing

Fans with humidity sensing will automatically turn on when the moisture levels in the room rise above a certain level.

Other Important Considerations

  • If you have an enclosed toilet in your bathroom, install a separate exhaust fan in that area.
  • Install the fan above areas which are more prone to getting wet — such as the shower area, the sink, or the tub region. When your bathroom has all of the above elements, place the fan midway between the toilet and shower or tub and sink. If you have a small bathroom, just install the fan at the center.
  • If you have a high bathroom ceiling, with height 8 feet or greater, you might need added ventilation.
  • Ensure that the exterior vent louver is completely sealed once you turn off the fan. Otherwise, cold air will seep in when the fan is not operational.


Currently, the market for bathroom exhaust fans presents innumerable options in terms of specifications, styles, additional features, efficiency, etc. You can go for an option that meets your existing layout, budget, and other important requirements (already outlined above). Settle on a product that complements your bathroom design while also ensuring that your home is safe from moisture-related damages. It is always recommended to only use a reputed HVAC installer to execute the bathroom ventilation installation process.

Read more: Kitchen exhaust fan maintenance

Bathroom Exhaust Fans: Everything You Need To Know was last modified: July 18th, 2022 by Anisha Dutta
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