You can use the existing switch wires and ductwork.
Easy way to install bathroom fan.
At this point you will strip the ends of the electrical wires and hard wire them into the unit.
In the bathroom insert the fan unit into the housing per the manufacturer s instructions.
The installation is easiest if you re replacing an existing fan.
Install the decorative plastic grille by slipping its mounting wires into the available slots in the housing unit.
Photo by keller keller photography.
Connect power to both switches through two pigtails spliced to the feed wire.
Connect the red wire to one switch terminal and the black wire to the other terminal.
Also it helps to get a fan that s the same size as your existing fan so you won t have to adjust the size of the ceiling hole.
Measure the ceiling opening and determine if it is large enough to accommodate your new fan.
Switch off the power at the fuse box.
For a fan and light switch with existing wiring splice the white wires and connect the grounds securely with wire.
For optimum performance locate it between the shower and the toilet.
Typically either a bare wire or green wire will attach to the side of the metal housing for grounding a critical safety measure.
Remove the existing fan leaving the old duct work and wiring.
Turn the power back on and test your new bathroom fan to make sure it s working.
This video shows how home renovation brothers dave and rich remove and install a bathroom exhaust fan.
Follow steps 3 10 of the new construction installation to complete.
If not you must cut around.
Fans are rated by cfms and sones.
Draw a mark on the bathroom ceiling where you d like to install the vent fan.