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of Home Improvements

*Installing a Bathroom Vent*

Many types of bathroom exhaust fans are available, from the simplest fans, to more elaborate models with built in lights, heaters and timer switches.Measure the size of your bathroom and make sure the fan that you choose is rated for your size bathroom. The broan rating is a measure of how quiet the fan is. Some fans are so loud that it can be heard a couple rooms away some models are designed to be mounted on the ceiling, while others are mounted to the walls.

Before starting to wire your fan always turn off the power to the switch at your circuit panel. Check the wiring requirements contained in the instruction booklet and follow them. Wiring at the switch should be performed after the unit has been installed. Your choice of switching for the installation determines the type of cable that must be run from the switch to the fan unit.

Installing a fan/light combination as a replacement for an existing light fixture is an easy project. The wiring is already in place, so the project requires no special knowledge of electrical wiring. For this installation, the light switch will operate both the fan and the light at the same time.

If you wish to operate the light and fan independently by separate switches, it will be necessary to run a 3-wire cable between the unit and the existing light switch and install a double switch at the electrical box. The switches should be wired as indicated in the drawing.

Consult the manufacturers instructions the wiring of different kind of fan combinations. Some times the cost of wiring a large combination unit will far exceed the cost of the unit itself.

If possible, place the housing in a position, which will allow you to fasten it directly to a ceiling joist. If this is not possible because of the location of the original light fixture, install wooden braces between joists to provide a solid attachment point for the fan housing. Hold the housing in place against the ceiling and mark around it to define the perimeter of your cut. Drill pilot holes in the corners, and cut along the lines with a drywall saw or jigsaw.

Run a length of cable from the existing light switch to the exhaust fan unit. If you wish to have separate switches operating the fan and light functions, use 3-wire cable. If your unit includes a heater and/or timer, additional cable may be required. Consult the manufacturer's instructions. This step is not necessary if you are replacing an existing fixture and do not require independent switch operation for the fan and light.

Many units on the market today have a heater/light and vent combo. The heater is essentially a large hair dryer in the ceiling. In order to wire these units a dedicated line and breaker in the circuit panel are required.

Make the necessary electrical connections at the fan unit using wire nuts. Follow the wiring diagram provided by the manufacturer. Simple fan installations may only require wiring bare copper to bare copper, white to white and black to black, while more elaborate units with lights and/or fans will require more connections. Attach the ground wire to the grounding clip provided on the housing. Push the wires into the wiring box area of the housing and install the cover.

Connect the duct to the fan housing.

Follow the instructions of the unit's manufacturer regarding how far away from the fan the insulation should be kept. Some units allow insulation to be right next to the housing. Others, particularly those with lights or heaters, may require that you add dams between the joists to keep the insulation a minimum distance away from the unit.

This is an important part of fan installation. Improper venting of the fan can cause moisture problems, which arise as a result of condensation forming within the vent. This condensation can run back down the duct, leaking around the fan and creating stains and problems in the surrounding building materials. Don't vent the moisture directly into the attic. After all, your goal is to avoid moisture problems, not transfer them to a different area of the house.
When possible, vent the fan through the nearest soffit. Or directly through the roof. The shorter the distance the vent is from the fan the better it will perform.

The fan unit can be connected to the soffit or roof vent using flexible plastic duct material. The duct material is easy to cut and it is expandable, which helps make fitting an easy task. Just clamp one end of the duct to the vent shroud on the fan housing and the other end to the vent. Installing the duct horizontally across the attic reduces the possibility of condensation trickling back down around the fan. Insulating the duct with insulation wrap also reduces the formation of condensation within it.

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