How to Replace an Extractor Fan

A kitchen with an extractor fan.
  • 4 hours
  • Beginner
  • $45
What You'll Need
Extractor fan
Foam tape
Fused spur
Oval plastic conduit

An extractor fan reduces moisture and distasteful odors in the air. It is important to keep the level of condensation levels low in your kitchen, bathroom, and laundry room. If your extractor fan is in need of replacement, don’t be distraught. Installing an electrical extractor fan is a cheap and easy job you can do yourself.

Choose the Correct Fan

Axial fans and centrifugal extractor fans are the two basic types of extractor fans. Axial fans are either mounted into a window or into an exterior wall. Centrifugal extractor fans are mounted into a ceiling. Determine which type of extractor fan you need to purchase based on where you will be mounting it.

You also need to choose a fan with the correct capacity. The capacity of a fan is volume in cubic feet per hour. Calculate the minimum capacity of the fan needed by multiplying the volume of the room (length x width x height) by the necessary number of air changes. The recommended number of air changes is listed below:

Kitchen - 10 to 15 times per hour

Bathroom - 6 to 8 times per hour

Bathroom with shower - 15 to 20 times per hour

Water closet - 6 to 8 times per hour

Living room - 4 to 6 times per hour

Fit the Fan

Positioning the new fan into the wall or the ceiling is fairly simple. An appropriate aluminum ducting, as well as the hole for the fan, should already be in place. Place the fan into the hole. When fixing a fan with a slated grille into a wall, fit the fan so that the grille is parallel to the ceiling. Insert the fan into the duct. Apply foam tape around the fan to fix the fan in position.

Do Electrical Installation

Before beginning the electrical installation, switch off the electricity at the mains before handling existing circuits. If the fan is in the kitchen, the fan is installed by fitting a fused connection unit. Wire the fans via a double pole switched the fuse spur. The poles must have a contact separation of at least 3mm. Fit the double pole with a 3 amp fuse and feed the fused spur off of either a ring main or a lighting circuit. Run a cable from the fused connection unit to a flex outlet adjacent to the fan.

On the other hand, if the fan is in the bathroom, make the wiring via a ceiling mounted pull cord double pole switch. You cannot use a surface switch in the bathroom because it can result in a serious injury.

All electric wiring must be fixed securely. If the wiring is in the wall, an oval plastic conduit must be used to cover the wires. Fans and fixed fused spurs cannot be located within reach of a person at the sink as water exposure poses a potential threat.

Electrical wiring can be very dangerous. If you do not have any experience with electrical wiring or in doubt, it is best to consult a licensed electrician.