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.