The Basics of Bathroom Ventilation

source: Venting Direct
NuTone, Model 665RP

Good bathroom ventilation is critical in maintaining your bathroom. Without proper ventilation moisture can build up which can not only cause mold and mildew to grow but can cause cabinets to warp, paint to peel and a whole host of other problems. So choosing a good bathroom fan can help prevent some big maintenance nightmares down the road.

Although the purpose of all bathroom fans is the same - to remove moisture and odors from the bathroom to the outdoors, there are a variety of types to choose from. The type you choose will depend on the location and how you want to install your fan.

• Ceiling-Mounted Exhaust Fans – this is the most common type of bathroom ventilation and, as the name implies, is installed in the ceiling. They expel air from your bathroom upwards and out through ducting to an external vent.
• Inline-Exhaust Fans – are mounted in-between ducting usually in the attic space. These fans tend to be very quiet and more powerful. They are also great for larger bathrooms because you can have multiple exhaust points with a single fan.
• Wall-Mounted Fans - are installed directly on the wall, creating a straight path to the outside; no ductwork is required.
• Combination Units – these combine the different types of fans with additional features, such as lighting and heat lamps.

What Size Bathroom Fan Do You Need?
The fan you select should be based on the size of bathroom you have. Bathroom fans are sized by the amount of airflow they provide which is measured by Cubic Feet per Minute or CFMs. The Home Ventilating Institute recommends that bathrooms under 100 square feet in size have at least 1 CFM of airflow for every square foot of bathroom area and a minimum of 50 CFMs. Bathrooms larger than 100 square feet are sized by the number of fixtures in the room, typically 50 CFMs per fixture. So if you have one toilet, one tub and one shower then you need at least 150 CFMs.

Fan Noise Levels
A factor you may want to consider when choosing a bathroom fan is its noise level. Industry noise ratings for quiet fans are 0.5 and 1.2 sones (1 sone is roughly equal to the sound of a refrigerator running). 1.5 - 2 sones is considered a little louder, but still within a good range, while anything louder than 2 sones is considered on the loud side.

Special Features
You will also want to consider any special features you may want on your bathroom fan such as lighting or heat lamps. Some fans have automatic activation according to pre-set humidity levels and others have a timer switch allowing you to run the fan for a set time. There are also fans with filters that reduce allergens in the air.

Web Resources
Here are some online resources with more tips on bathroom ventilation.

Bathroom Ventilation Guidelines from HVI
Learn more about how to size your bathroom fan from the experts at the Home Ventilating Institute.

Energy Efficient Bathroom Fans
Be green by learning which bathroom fans qualify for the Energy Star rating.

Why Use An Inline Bathroom Fan?
Learn about the advantages of using an inline fan for bathroom ventilation.

Manufacturers of Bathroom Fans
Here’s a list of the top manufacturers of bathroom ventilation fans.
Aero Pure - http://www.aeropurefans.com
AirKing - http://www.airkinglimited.com
American Aldes - http://www.americanaldes.com
Broan- http://www.broan.com
Continental Fan - http://www.continentalfan.com
Delta - http://www.deltabreez.com
Fantech - http://fantech.net
GE - http://www.geindustrial.com
Honeywell - http://yourhome.honeywell.com
Hunter - http://www.hunterfan.com
Lexton Fans - http://www.lextonfans.com
Marley - http://www.marleymep.com
NuTone - http://www.nutone.com
Panasonic - http://www2.panasonic.com
Renewaire - http://www.renewaire.com
Soler and Palau - http://www.solerpalau-usa.com
Suncourt - http://www.suncourt.com
Vents US - http://www.vents-us.com