How to Install Bathroom Vents

What You'll Need
Exhaust fan
Stud finder
Screwdrivers, Phillips and flat head
Wire nuts
Wire Strippers
Electrical tester
Exhaust duct kit
Safety glasses
Jab saw

Whenever you take a shower or a bath, your bathroom will fill with steam. Steam is caused by the evaporation of water that soon becomes liquid again. If it is not directed away from your bathroom, steam and moisture can cause problems with mold and mildew. The best way to remove steam from your bathroom is to install a bathroom vent and an exhaust fan. The fan will generally be fixed into the ceiling and will pull moist air out through a hose to the outside of your home. You will need to make sure that the vent runs outside or you’ll simply end up with mold transferring to another part of the house.

Step 1 - Selecting Your Fan

There are many brands of fan available. You’ll need to buy one that operates to at least 80 CFM (cubic feet per minute). A much higher rate is preferable but this will cost more. Also, look at the noise rating on the packing. An ideal combination will be a fan with 100+CFM and a low noise rating although, once again, this will be more expensive.

Step 2 - Cutting the Ceiling

Use a stud finder to locate the ceiling studs. The duct kit will have a template for the ceiling opening. Use this to mark an opening on the ceiling between the studs and cut the opening with a jab saw, making sure you wear safety glasses while working. It’s best to cut slightly inside the markings and then cut a little more out if the opening is too small.

Step 3 - Wiring the Fan

The duct kit will include a wiring guide. The simplest way is to wire to the lighting circuit in the bathroom so the fan will come on whenever you switch on the light. Before doing any electrical work, turn the circuit off at the breaker and check it’s off by operating the bathroom light switch. Strip the required wires using the wire strippers and connect using the wire nuts. Turn on the breaker and the bathroom light to check the wiring is correct and that the fan comes on.

Step 4 - Mounting the Fan

Ideally, you’ll be able to mount the box for the fan directly onto the joists in the bathroom ceiling with a screwdriver and the screws provided with the fan. Failing that, use the hangers supplied with the exhaust duct kit. Before fixing into place, attach the hose to the box and run through the attic to the outside wall. Now, screw the fan to the box and attach the outside trim, if any is provided, to the bathroom ceiling.

Step 5 - Installing the Vent

Using the jab saw and the template in your duct kit, cut a hole for the vent in your outside wall or in the soffit where the hose will terminate. Screw the outside of the vent to the outside wall. Part of the vent will protrude through. Attach the hose to this and tighten to keep it in place. The vent should have a cover to prevent moisture getting in but which will be forced open by air coming through the hose.