Choosing a bathroom fan

Choosing a Bathroom Fan

Choosing a bathroom fan with simple steps and tips to make it easy. The bathroom exhaust fan must be the right size for the right sized bathroom.

For anyone who has been in a hot steamy bathroom, the benefits of an exhaust fan are fairly obvious. By pushing air out of a bathroom, exhaust fans alleviate foggy mirrors, dripping windows and bathroom odors.

Benefits of using a bathroom fan

Bathroom exhaust fans have a few long-term benefits for your home. Exhaust fans remove excessive moisture from the bathroom and your home. This moisture will cause paint and wallpaper to peel, and mildew to thrive. In extreme cases, too much moisture in a home will cause rotting drywall and rotting window frames.

The latest generation of bathroom fans is efficient and fairly quiet. These fans come in different styles. Some exhaust fans work on one switch or two switches. This means you can control different aspects of the exhaust fan separately. Some bathroom exhaust fans are combination fans, lights and even heaters. And they’re fairly affordable, ranging in price from about $40 to $100.

About the only disadvantage you may find with an exhaust fan is itsinstallation. You may have a more difficult time in older homes. The installation process will vary from house to house and takes some planning.

Choosing a bathroom fan that is right for you

Before purchasing a fan, the first step is to take inventory of what your bathroom now has. If you already have a fan installed, the work to install a new unit may be minimal. If you only have an overhead light fixture, be prepared to cut a hole through the ceiling to install a new fan. And if you don’t have an existing light fixture in the bathroom, you’ll need to run an electrical line to ceiling to power the fan. That type of work will probably require the services of an electrician.

As you consider any home improvement, remember to consider your budget and skills before you start the work. If it’s spring and you’re looking to take care of your home, think of a checklist of what you should look for in your home.

Calculating CFMs: (multiple the square footage of the room by 1.07)

The next step of the installation process is choosing the correct fan capacity. A simple formula to determine fan capacity is to multiply the square footage of the room by 1.07. That number will give you the minimum amount of CFM – cubic feet per minute needed to exhaust moisture and odor.

  • A 10-foot-by-6-foot bathroom of 60 square feet multiplied by 1.07
    would require a minimum CFM of about 65.
  • A 15-foot-by-15-foot bathroom of 225 square feet multiplied by 1.07 would require a minimum CFM of about 240.
  • To give you some perspective, the size of most bathrooms in a home is under 40 square feet.
  • And, for additional perspective, the size of a large bathroom would be around 200 square feet.
  • This is the first tip to choosing a bathroom fan.
Installation Steps

The best way to mount an exhaust fan is to install a wall unit on an outside wall. Ideally, such a bathroom exhaust fan unit is placed close to the shower but far from the bathroom door. The ductwork out of the building is usually minimal.

Cut the electrical power

Start the actual installation by shutting off the power to the existing light fixture or fan at the circuit breaker or fuse box. Remove the light fixture. Remove the electrical box (it may be held on via a nut up on the inside top of the box, or screwed into a ceiling joist through the side). Next, try to determine where the ceiling joist is. You can use a nail or punch to help locate the joists through the ceiling or location them from the attic.

Anchor the bathroom exhaust fan box

Exhaust fans are anchored to a ceiling by attaching them to a joist or joists. Depending on the fan, you may have to install support blocks on the inner side of joists to mount the fan housing.

The housing of some fans are mounted directly to one joist through openings on the side of the housing, or through mounting tabs on the exterior of the housing. Other housings use adjustable hanger bars to install the fan housing between two joists. After locating the joists, next position the fan housing around the light fixture opening and trace the outline of the housing on the ceiling. Using a small handsaw, cut out the opening.

If you have drywall ceilings, you will have an easier time installing the unit. Cutting drywall is easier. On the other hand, plaster ceilings are more work. Plaster ceilings may crumble around the edges and you will need to cut through the plaster and the backing material.

Next, place the housing in the opening and use a piece of folded cardboard or a wood shim to keep it place. Make sure you secure the housing unit so that the collar or lip of the unit is flush with the ceiling.

Installing the exhaust ductwork

Next, figure out the best way to run the ductwork coming out of the exhaust fan. In most cases, manufacturers recommend using ductwork to run the exhaust out of the attic and through a wall or the roof.

Some manufacturers recommend using flexible dryer hose – three-inch round ductwork. You’ll need to install the ductwork from the unit to the exterior wall or the roof. Make sure you install a roof or wall cap on the exterior of the ductwork. You’ll need this cap to keep animals and insects out of the home.

Electrical wiring and connections

Finally, follow the manufacturer’s instruction to make the electrical connections to the exhaust fan. The connection of the pipe containing the existing wiring into the fan housing may require a few electrical adapters available at most home improvement stores. If you are installing an exhaust fan and light fixture; or a fan, light and heat lamp fixture, you’ll need to run additional wiring through the existing conduit if you wish to operate the various appliances separately.

We hope these steps and tips help you in choosing a bathroom fan that is right for your bathroom and right for your home.