A bathroom exhaust fan not only prevents steamed up windows and mirrors, but also helps reduce moisture-related problems in the bathroom. It helps prevent the growth of mold and mildew, and keeps towels and curtains from souring. Installing a bathroom fan presents few problems. Perhaps the most difficult part of the installation is running the duct work to the outside.
Instructions
1. Choose an exhaust fan adequate to vent the amount of space in your bathroom. Measure your bathroom and figure the total square feet of floor space in the room. Multiply that number by 1.1 if you have an 8-foot ceiling, 1.25 for 9 to 12-foot ceilings and 1.5 for cathedral ceilings. This will give you the needed cubic feet per minute (CFM) airflow. Check the fan unit to see that its CFM rate meets or exceeds the needs of .
2. Cover the floor and fixtures below the area where you will install the fan with a drop cloth. Use the stud finder to find the ceiling joists and cut a square in the ceiling between two joists large enough to accept the fan housing box.. Cut a second hole into the attic the size of the flexible duct, if you are running the duct work out that way or through the roof. If not, trace the joists to where it meets the soffits just under the roof eaves and locate the place for a soffit vent for the duct.
3. Cut the duct hole into the attic with a saber saw or cut a vent hole in the soffit. If you vent to the attic, cut a hole in the attic gable wall or in the roof. Install the soffit vent, roof vent or gable vent according to manufacturer's instructions. Push the flexible duct through the outer vent hole and clamp to the inside of the vent plate before screwing the vent plate in place. Feed the duct between the joists or through the attic and down into the opening you cut for the fan assembly.
4. Run the 12-gauge electric wire from the junction box in the attic or ceiling to which you intend to attach the fan back to the hole for the fan housing. Make sure the circuit has a breaker strong enough to run the fan. Run the 14-gauge wire from the fan box through the ceiling and fish it down inside between the studs where the wall switch is located.
5. Screw the fan housing box between the ceiling joists in the opening. Attach the duct to the duct mount behind the housing box with duct clamps before screwing the box in place. Fish the power cable and switch wire through the fan box housing and attach the wires to the appropriate leads using screws or wire nuts. Be sure the switch leads are attached to the wires going to the switch box.
6. Attach the power wire to the appropriate leads on the fan and with screws or wire nuts. If you are installing a fan/light combination, use 3-wire 12 gauge cable instead of the 14 gauge 2-wire cable to run to the wall switch. You must have the 3-wire cable to operate the fan and light switches. Follow the manufacturer's diagram to ensure proper connections and ground wire hookup on the fan/light assembly.
7. Assemble the rest of the fan mount by attaching the fan, fan blades, and light and light bulb to the appropriate bracket mounts in the fan housing and fan/light assembly. Then cover the whole assembly and housing box with the fan cover plate and clip or screw the cover in place.
8. Unscrew the switch plate from the wall, and unscrew the switch and switch wires and pull them out of the switch box. Pull out the old switch box, and fish the old and new switch wires out of the wall and through the back of the new switch box. Install a two or three switch mounting box to replace the old single switch box -- a two switch box if you install a fan only or three if you install a light/fan combination. Cut a new hole with the saber saw that is large enough to accept the new switch mounting box. Mount the box in the new hole with screws. Attach the fan wires to the switch or switches according to the manufacturer's instructions. Then mount the fan switches in the new switch box and screw into place. Reattach the old light switch to its wires and remount it in the new switch box beside the others..Screw the new switch plate to the box over the switches.
9. Turn on the circuit breakers for the bathroom, and test the fan and light switches.
Tags: light assembly, soffit vent, switch wires, your bathroom, according manufacturer, according manufacturer instructions, appropriate leads