Updating bathroom ventilation isn’t usually a big deal. However, in an older home, the outdated electrical system and lack of an existing vent system can make it tough. When a homeowner wanted to add ventilation to her older home, master electrician Heath Eastman was the pro for the job, and he took us along for the ride.
Consider the Exhaust Fan Type
There are two exhaust fans to consider. The first is a standard bathroom vent fan, which has a motor installed directly on the grill’s other side. These units are usually easier to install but can be very loud. The other option is a remote fan, which has a length of ductwork connecting the fan to the bathroom. This typically makes them quieter, though a bit more difficult to install.
You’ll Need Access
If there isn’t an existing duct to work with, you’ll need access to the ceiling from the bathroom or from the attic above. You need to ensure there is room for the fan and that there is direct access to the exterior of the home, whether through the wall or through the gable.
Time to Pick a Switch
There are a few options for exhaust fan switches. The first is a standard switch to turn it on and off. The next is the humidity sensor, which activates when the humidity in the room reaches a specific percentage. Finally, a timer switch can be installed, with several buttons for different run times.
Choose a Grill Location
You’ll need to choose a location for the grill. For an exhaust fan, the most common (and best operating) location is directly above the shower, but the vent can be installed anywhere within the room. This is especially true when installing a remote fan, as they pull a lot of air from the bathroom.
Electrical Considerations
You’ll need power—controlled by the switch—to power the fan. In newer homes with modern wiring, tapping off an existing wire is usually not a problem. However, in homes with BX wire (a type of metal wire without a copper ground), you’ll need to find power elsewhere and run a new wire to the motor and switch.
Ductwork Connections
Standard fans typically connect directly to a vent placed in a hole drilled directly through an exterior wall. A flexible 4-inch, insulated duct and band clamps are typically all that’s required. However, with a remote fan, duct work is more challenging. The remote fan needs to be installed and connected to the grill with flexible ductwork. Then, rigid 4-inch duct work needs to be installed between the fan and the exterior of the home, typically through a vent drilled through the gable end.
Resources
Heath installs a remote motor bath fan in the attic above the bathroom.
To cut a hole in the ceiling for the exhaust grille, Heath uses a 6” hole saw.
For the new switcher, Heath installs a timer switch that has the option of setting the fan for 10, 20, 30, or 60-minute increments.
The sheet metal technician installs 4-inch ductwork, which connects from the damper to the remote motor and then out the exterior of the gable end.