Priority Electrical

Minimum Air Changes Required Per Hour

To calculate the correct fan required for a particular room you need to know the room volume in cubic metres, i.e. length x breadth x height, and then multiply by the number of air changes required.

 

Bathroom & Shower Rooms
3
Conference Rooms
8
Living & Other Domestic Rooms
3
Sports Facilities
6
Bedrooms
2
Garages
6
Meeting Rooms
4
Store Room
3
Cafés
10
Hairdressing Salons
10
Offices
6
Toilets - Domestic
3
Canteens
8
Halls & Landings
3
Restaurants & Bars
6
Toilets - Public
10
Cellars
3
Hospital Rooms
4
School Rooms
2
Utility Rooms
15
Changing Rooms with Showers
15
Laundries & Launderettes
10
Shops
8
Workshops
6

 

  Example 1 Example 2
Room Bathroom Kitchen
Volume 2.0 x 2.0 x 2.0 = 8m³ 2.8 x 2.8 x 2.8 approx = 22m³
Number of Air Changes Required 3 10
Performance 8 x 3 = 24m³/h 22 x 10 = 220m³/h
Fan Required XF100T = 85m³/h WF150A = 220m³/h

Stale air is also removed by installing the appropriate Manrose fan. In certain circumstances, such as in toilets, a timer is incorporated to provide an automatic turn-off period of 15 minutes as stipulated in The Building Regulations.