Choosing Bathroom Ceiling Fans, AKA Exhaustion or Ventilation Fans

Ventilation - Bathroom exhaust fans for the ceiling.

Exhausting Moisture and Improving VentilationWith Bathroom Ceiling Fans

Having a bathroom remodeled is an exciting experience for homeowners. You have the ability to completely remake the room to match your specific taste and style. You have so many creative choices to explore, from choosing your vanity and top to lighting, tile, flooring, fixtures, stand alone tub, or steam shower, colors, skylights, it's all fun, creative and in the end you can have the spa-like oasis of your dreams.

One area homeowners rarely spend a lot of time thinking about, but is nevertheless one of the most important elements in your bathroom is your ventilation options. The most beautiful bathroom in the world will become a problem if the ventilation isn't appropriate for the space. Bathroom ceiling fans are critical for removing moisture from the room to avoid mold, mildew, slippery surfaces or worse.

Let's explore why your ceiling fan is the most important element in your remodel and what to consider when purchasing bathroom ceiling fans.

What are Bathroom Ceiling Fans?

Unlike a 60 inch ceiling fan for moderating temperature, a bathroom ceiling fan is a ventilation device that is usually placed in the ceiling or wall of the bathroom and ducted to the exterior of the home. It's designed to remove and draw out stale, impure, very humid air to improve the quality of the air inside the room.

A properly installed exhaust fan will remove the excess moisture, humidity, odors, and other pollutants like aerosols and perfumes, from your home. It is also designed to remove water vapor that has accumulated on the mirrors, floor, tile and walls. With proper ventilation you will be much more comfortable when using the bathroom. Along with comfort by removing moisture, deterioration of interior wall coverings, structural framing and insulation due to water damage is minimized or eliminated saving you from costly repairs in the future.

Four Key Considerations When Choosing Bathroom Ceiling Fans

There are basically four major factors to consider when shopping for your ventilation system.: size, sound, location and operation. You also need to consider your local building codes. They will specify the minimum requirements necessary to meet code.

Proper Sizing

Fans are rated by the amount of air they move. This number is measured as “cubic feet per minute” or CFM. Most local building codes require a minimum of 50 CFM for proper bathroom ventilation. The Home Ventilating Institute and the National Kitchen and Bath Association both recommend a minimum of eight air exchanges per hour. This means that bathroom ceiling fans typically will exceed minimum code requirements.

At Forward Design build we understand the math behind sizing your bathroom ventilation. As a quick measure, if your bathroom ceiling is 8-feet, you can plan on 1 CFM per square foot of space, for example if your bathroom is 10-feet by 8-feet, an 80CFM unit will do the job. Proper sizing is important. If you an oversized unit, it can increase your energy costs.

Considering Sound

Once CFM is determined, we consider sound levels. Bathroom fans are rated using a measurement called a sone. One sone is about the same level as an operating refrigerator. If the fan is too loud, the homeowner may not use it. Extremely quiet units rated at less than one sone are available. It's also possible to locate the exhaust fan away from the room, in the attic for example, and then multiple bathrooms can be ducted and vented through a single unit.

Locating Your Fan

Bathroom ceiling fans are built for two reasons controlling moisture and odor. Where you place them in your bathroom is important for proper functioning. Because the shower and tub are most responsible for moisture, placing one intake in the ceiling near the shower makes sense. This may not address toilet odors, so a second intake in the wall or ceiling nearest the toilet is a good option, depending of course on the size of the room, and the CFM of the unit.In a larger bathroom with a separate tub and shower, a third intake may be necessary. Work with your contractor to determine the best placement for your bathroom layout.


Many homeowners opt to have the fan operate on the same switch as bathroom lighting. While this is ok, it's not always effective at removing large amounts of moisture. For example, moisture can remain in the ductwork of your home for hours. When your fan is located with the light switch, often the fan is turned off when you leave the room. We've found that having the fan controlled by a timer, or humidistat is much more effective.

Choosing bathroom ceiling fans for exhausting moisture, while not as glamorous as searching for the perfect marble vanity top, or lighting, is one of the most important aspects of a successful bathroom remodel. Taking the time and doing the research is important. At Forward Design Build we help our Ann Arbor, MI clients to design and remodel their dream bathrooms, including choosing and properly installing the right ventilation. If you're planning a bathroom remodel give our expert team a call. We'll help you with every aspect of your project, from creating the perfect design, to installing the perfect ventilation system!

Forward Design Build is a residential design-build firm in Ann Arbor, Michigan that is known for its commitment to craftsmanship and communication. We are committed to improving our neighbors quality of life with inspired design and creative remodeling. Our homes are highly functional, exquisitely beautiful, and remarkably comfortable. Contact us to speak with an expert about your new home or remodeling project.