Choosing the right fan

Selecting the right fan is important. Choose an Axial fan to move air over short distances or a Centrifugal fan for longer distances. Humidistat fans control the humidity in rooms where condensation is a problem.

Bathroom regulations

Under IEE Wiring Regulations (16th edition), bathrooms represent an increased electrical hazard. The regulations define various zones in the bathroom and demand a minimum of IPX4 in Zones 1 and 2 of the bathroom.

Addvent offers a range of IPX4 rated fans which meet these regulations and also offer a range of IP57 fans recommended for added safety. For more information on these regulations please refer to the Institution of Engineering and Technology website www.theiet.org.

Please refer to our Guide to Using Electrical Equipment in Bathrooms.

Installation

When siting and installing extractor fans, the following should be considered:

  • site the fan as far away as possible from the air inlet to the room;
  • the fan should be sited as close as possible to the moisture source;
  • avoid installing close to heat sources to prolong motor life;
  • in bathrooms the fan must not be within reach of a person using the bath or shower and must conform to IET regulations;
  • it is preferable to use a loft or ceiling void for ventilating shower rooms or bathrooms;
  • where ducting runs through unheated areas it should be insulated to prevent condensation. Vertical duct runs should be avoided;
  • ensure adequate air leakage into the rooms to provide replacement fresh air;
  • Do not install extract fans in rooms where open flued appliances are sited.

Ventilation products should always be installed by competent electrician.

Types of fan

  • STANDARD for remote switching through a wall light or separate switch;
  • TIMER with a built-in adjustable time delay operated by the light switch;
  • PULLCORD with a built-in pullcord switch;
  • HUMIDITY control with a built-in sensor which operates the fan automatically;
  • PIR sensitive to movement, these fans switch on and off when a room is entered or vacated.

Fan selection

To calculate the right fan for your needs, you will need:

  • the room size (length x width x height)
  • to calculate the room volume the air change rate (from the chart below)

An example calculation is shown below.

Minimum air changes required per hour

BATHROOM/SHOWER

3

BEDROOMS

2

CAFES

10

CANTEENS

8

CELLARS

3

CONFERENCE ROOMS

8

GARAGES

6

WORKSHOPS

6

HAIRDRESSING SALONS

10

HALLS AND LANDINGS

3

HOSPITAL ROOMS

4

KITCHENS (DOMESTIC)

10

LAUNDRIES/LAUNDERETTES

10

LIVING/DOMESTIC ROOMS

3

MEETING ROOMS

4

OFFICES

6

RESTAURANTS/BARS

6

SCHOOL ROOMS

2

SHOPS

8

SPORTS FACILITIES

6

STORE ROOM

3

TOILETS (DOMESTIC)

3

TOILETS (PUBLIC)

10

UTILITY ROOMS

15

CHANGING ROOMS WITH SHOWERS

15

Example: For example a kitchen 3m long x 3m wide x 2.5m high has a volume of 22.5m³ and requires 10 air changes: 22.5 x 10 = 225m³/hour. A suitable fan would be an AVX150MP

Technical Information

Technical Information

Addvent has published its corporate branding guidelines. These are available to download below.