How To Add A Bathroom Exhaust Fan

How to Install a Bathroom Fan

Updated: October. 15, 2021

Supersede your old, noisy bath fan with a tranquility, free energy-efficient model

how to install a bathroom fan Family Handyman

Replace that old noisy bath fan with one that's whisper quiet and clears the air faster with better airflow. You often can practise information technology in less than a day with piddling or no ceiling repair.

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Time
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Step 1: Plan the bath exhaust fan replacement

A new generation of efficient and quiet exhaust fans is at present available at home centers and from heating, ventilation and ac suppliers. The new fans are nigh silent. They're as well much more powerful and utilize less energy than the older models. They can fifty-fifty be left on full time if y'all need continuous ventilation. (Nigh ordinary fan motors would burn down out.) See "Shopping for a Serenity Fan," beneath, for more details.

In this article, we'll evidence yous how to remove an old bath fan and install a new quiet 1. In virtually cases you lot can practise an exhaust fan replacement in less than a day with footling or no ceiling repair. While nosotros're at information technology, we'll show you how to replace typical 3-in. uninsulated duct with much superior 4-in. insulated ductwork.

This project involves electrical wiring, then call your local electric inspector to find out if you need a permit.

Installing a fan requires only uncomplicated carpentry and electrical skills. You'll need bones paw tools, a power drill and a jigsaw. The basic operations include hand sawing a small drywall opening, driving sheet metal screws into aluminum ductwork, cut aluminum duct, climbing on the roof and sawing a larger roof vent opening, and disconnecting and reconnecting electrical wires. If you meet problems y'all can't handle, such as complicated electrical wiring, tight duct clearances, water impairment at the roof vent cap or a steep roof pitch, don't hesitate to call a licensed electrician.

You'll accept to go into your cranium and walk on your roof, so play it safe. Vesture a long-sleeve shirt, long pants, boots, a hat and a dust mask to protect yourself from dust and insulation in the cranium. While on the roof, use roof brackets, roof cleats or a rubber harness for secure footing and autumn protection. And if your roof is also steep or you don't feel confident upwardly there, hire a pro for this role. The bathroom fan nosotros're replacing is fairly typical. It's located in a ceiling with an accessible unfinished attic above.

The fan is properly wired and ducted with iii-in. uninsulated ductwork to the roof. If your old fan unit has additional features similar a calorie-free or heater that operates off a second switch, your electrical wiring will be more complex. If the rewiring confuses you lot, consult a licensed electrician to work out the details. If you accept a second floor above the fan, measure the summit of the space available. The new, quieter fans are taller than the quondam ones, at least 7-1/2 in. tall. While information technology should fit into typical floor joist infinite, check the fan dimensions to brand sure.

If y'all don't have an attic above, as we show, you'll have to practise the entire installation from below. This means you'll take to cutting open the ceiling a bit (and patch it later!) to get the fan in and run ductwork to a wall vent cap. The connections volition be the same equally nosotros evidence in the photograph series. However, changing to a larger wall vent cap can exist more complex if y'all accept brick, stucco or vinyl siding rather than wood. If yous're unsure how to proceed, check with a siding specialist for advice.

Footstep 2: Remove the onetime fan

Photo 1: Pull out the erstwhile motor assembly

Turn off the ability at the main panel. Pull down the grille cover and remove it. Then unscrew or pry out the old fan motor assembly using a screwdriver.

Photo 2: Disconnect the wiring

Remove the electrical cover plate. Carefully slide out the wires and remove the wire connectors. Turn on the fan switch (on the wall) and test the wires with a voltage tester to make sure the power is off. Untwist the wires. Remove the lock nut from the cable.

Photograph three: Remove the old housing

Become into the attic and unscrew the old fan housing from the joist. Remove the cablevision and pull out the wiring. Untape or remove the clamps that hold the ductwork at the housing and at the roof.

Earlier you start, you'll have to turn off the electricity to the fan at the main console. With the fan running, flip circuit breakers or loosen fuses until it stops.

Put on your safety goggles. As y'all pull down and snap off the old grille, watch out for falling debris! You'd be amazed at how much crud tin spill out. Then unplug the motor and remove it from the housing (Photo i). Information technology volition be held with clips or screws. Wear gloves. The edges may exist sharp.

The electric connections are usually in a small splice box (Photo 2). Bank check the wires for power with a voltage tester to brand sure information technology's off. Then disconnect them.

Next y'all have to get up to the attic. You need a ability drill, screwdriver, utility knife, metal snips, wire cutter, wire stripper and a piece of work calorie-free. To avoid extra trips, conduct all the tools with you lot in a bucket. To make it easier to work in the attic, find a small slice of plywood to kneel or lie on—approximately 2 x three ft. In the summer, work in the morning. Attics get hot on warm days. Push the insulation back from the old fan housing and remove the housing (Photo 3). Well-nigh older fans volition be mounted direct to a joist. The screws might exist hard to remove. A power drill simplifies this task.

Caution: Aluminum wiring

Aluminum wiring requires special handling. If you have aluminum wiring, telephone call in a licensed pro who's certified to work with information technology. This wiring is boring gray, not the tiresome orange that's characteristic of copper.

Step 3: Install the new fan and duct

Photo 4: Fit the new fan housing

Trace the new fan housing outline on the ceiling over the old opening. Overstate the hole with a drywall saw. Pay attending to ceiling joist locations.

Photo 5: Mount the housing

Align the fan housing from above, making certain the housing is oriented properly for ductwork and electrical connections. And so screw the mounting brackets that hold the fan to each joist with 1-in. drywall screws.

Photograph 6: Attach the duct

Screw the four-in. aluminum elbow to the fan'due south exhaust port using three 3/viii-in. self-tapping Phillips sheet metallic screws. Take intendance not to hamper the damper flap inside. Then slide out the inner liner of the flexible ductwork, gather iii or four of the metal rings and utilise three more screws to attach the liner to the elbow.

Photograph 7: Secure the insulation

Pull downwards the insulation jacket and tighten the 6-in. metal clamp at the elbow. Cutting the duct to length with a utility knife and wire cutters and attach a half-dozen-in. piece of directly aluminum pipe to the stop with screws and a clamp, leaving well-nigh three in. of metal exposed. Using metal snips, cut the three-in. exposed end of the aluminum pipe at an bending to friction match the roof pitch.

Photo viii: Connect the wiring

Remove the plate at the electrical splice box and pull out the fan wires. Push the electric cable through the hole provided and anchor it with a cable clamp. Twist together the electrical wires (white to white and red or black to blackness) and install the connectors. Attach the blank copper wire to a basis clip or a screw on the plate. Fold the wires back into the electric box on the housing and supercede the cover.

Photo nine: Caulk the ceiling gap

Caulk the ceiling/housing joint with silicone or another high-quality caulk.

Now get back down to the bath. Hold the base of the new fan housing to the ceiling and draw the new opening size (Photo iv). Most new, serenity fans are larger than the old fans. If not, you'll have to patch the ceiling with drywall. To simplify cutting, line up two sides with the existing pigsty. Article of clothing goggles while cutting.

Before going back into the attic, cutting a piece of insulated flexible duct approximately 18 to 24 in. longer than the quondam duct and cut one slice of 4-in. dia. aluminum ductwork 6 in. long. Take them into the cranium along with the fan, fan mounting brackets, aluminum elbow, sheet metallic screws, drywall screws, electrical cable staples, electrical clench, caulk and duct clamps. You may too demand blocking to attach to the joists to back up your new fan housing.

You'll need a helper to mountain the new fan. Slide the mounting brackets on and extend them to the joists. Align the fan with the new drywall hole. Then ease it downwardly to your helper, who will hold the housing flush to the ceiling while you spiral the brackets to the joists (Photo 5).

After installing the fan, run the ducts. Attach the aluminum elbow to the exhaust port (Photo 6) and the duct liner to the elbow. So measure out and cut the flexible insulated duct. The ideal duct run should be as direct equally possible, with the fewest turns. Extend the duct from the exhaust port to the roof opening, but don't stretch information technology and so tight that information technology kinks. Then terminate connecting the insulated duct to both aluminum ends (Photograph 7).

With our fan, the wiring is done from the cranium. Some models wire from below. In either case, clamp the electrical cable to the housing with a standard clench with vi in. of wire extending into the box. Strip 5/eight in. of insulation off the terminate of each wire and connect the wires (Photo 8). Staple the cable to a framing fellow member inside 12 in. of the cablevision clamp. Yous may find that the existing electrical cable is too short to accomplish the new fan. If the cable runs to a nearby junction box, you can replace it with a longer section. Otherwise, y'all'll have to install a new junction box. If y'all're not familiar with the rules of wiring, call in a licensed electrician to do this office. In whatever example, have your work checked by the local electrical inspector.

Seal the perimeter of the fan housing with flexible caulk (Photo nine). This is critical for reducing audio transmission too as air leakage. Replace the insulation, making sure to cover the fan housing. Await around for all your tools earlier you get back down!

Step 4: Install the cap

Photo 11: Ballast the duct

Reach into the roof pigsty and pull upwards the angled end of straight duct, leaving about 3/4 in. above the roof surface. Spiral information technology to the sheathing with one/2-in. self-tapping canvas metal screws. Seal the gap betwixt the duct and the shingles with silicone caulk or another high-quality caulk.

Photograph 12: Slide on the vent cap

Slide the new vent cap under the shingles for a proper fit. Pull it out. Utilise covering cement to the shingles where the height and side flanges volition residual. Nail in place.

Photo xiii: Seal the cap

Gently elevator the shingles and nail the vent cap at the top and sides using roofing nails. Apply roofing cement under the shingles at the sides and the superlative of the vent cap and over nails.

Consummate the roof work in i trip. While working on the roof, y'all'll need the new roof vent cap, a scrap of the straight aluminum ductwork (cut one end to match the roof angle), a jigsaw, a tape measure, roof cement, caulk, a utility knife, roof nails, one/2-in. Phillips self-tapping sail metal screws, metal snips, a pry bar, a carpenter'southward pencil and a hammer. Clothing a tool belt or apron or you'll exist going up and down the ladder retrieving stuff that slides off!

If you're not fully confident working on your roof, install a pair of roof brackets along with a two×10, or blast a 2×4 cleat to the roof a few feet below the vent opening. Information technology'll requite you a more secure area to place your feet every bit yous work on the roof.

Replace the erstwhile vent cap with a new ane. Remove the quondam one care fully and then you don't impairment shingles. They can be brittle, especially on a common cold day. Then enlarge the sometime 3-in. hole to fit the four-in. duct, using the 4-in. duct as a template. The opening will exist oval-shaped in the direction of the roof slope (Photo 10). Reach through the roof and pull the straight aluminum duct up through the hole, with the angled end extending 3/4 in. to a higher place the roof surface. Spiral the duct to the sheathing (Photo 11). A magnetic drill bit is helpful hither. Bulldoze a roofing nail through the side of the duct to temporarily ballast information technology. Seal around the edge with caulk to continue condensation from running back down the duct or under the shingles.

Check the screen and the damper in the new vent cap before installing information technology to brand sure both are in place. When yous're done, fill any nail holes you lot put in the roof with roofing cement.

To consummate the job, install the decorative grille. At present is the moment of truth. Turn the power dorsum on and listen to the fan—if y'all can hear information technology!

Shopping for a Quiet Fan

A quiet fan has a "sone" rating between .5 and 1.five. A sone is a measure out of loudness. The lower the number, the quieter the fan. By contrast, typical low-cost bathroom fans range from 2 to more than than 5 sones (which you tin easily hear in the next room). Select the ventilation chapters of the fan that fits the size of your bathroom. To apace estimate the cfm needed (cubic feet per minute, or how much air a fan moves), a "rule of thumb" is to multiply the length of your bathroom by the width and circular up. For example, an 8 x 10-ft. (lxxx sq. ft.) room would need a vent rate of 80 cfm and would require an 80-cfm fan. Quiet fans have better motors (rated for continuous operation), heavier-duty housings and larger ducts, usually 4 in. They cost considerably more than standard fans.

Additional Information

The Materials

Required Tools for this Project

Have the necessary tools for this DIY projection lined up earlier you starting time—you'll save fourth dimension and frustration.

Gloves, Trouble light and Goggles

Required Materials for this Project

Avoid last-infinitesimal shopping trips by having all your materials set ahead of time. Hither's a listing.

Originally Published: November 28, 2018