what air extractor fans to site in each room for a good air extraction – Manrose advice

Poor ventilation causes problems, so there is the need for extractor fans in most of the venues in a home. Read below what the Building regulations say about the different rooms and their requirements, some examples of fans needed for a bathroom / a kitchen, the minimum air changes required for different rooms in the house, and the Manrose Extractor Fans available via SparksDirect. This article is also written to answer the question posed by one of our visitors here.

Building Regulations – air extractors for home

  • Air Extractor fans in the  Bathrooms/Shower Rooms: The Regulations require a fan capable of minimum extract capacity of 15 litres per second 54m3/hr (32CFM) when installed(see the Manrose ShowerLite range).
  • Air Extractor fans in the  Toilets (Separate from a Bathroom): The Regulations require a fan capable of a minimum extract capacity of 6 litres per second 21m3/hr (12CFM) when installed. N.B. If a room does not contain an openable window the fan should be fitted with a 15 minute over-run timer.
  • Air Extractor fans in the Kitchens: The Regulations require a fan capable of extracting 60 litres per second 216m3/hr (127CFM) when installed(see the Manrose Kitchen fans 150mm).
  • Air Extractor fans in the Utility Rooms: The Regulations require a fan capable of extracting 30 litres per second per second 108m3/hr (63CFM) when installed.

Examples of Air Extractor Fans needed

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.

Example: The extractor fan needed for a Bathroom

  • Volume: 2.0 x 2.0 x 2.0 8m3;
  • Number of Air Changes Required: 3;
  • Performance: 8 x 3 24m3/h;
  • Fan required: Manrose XF100T 85m3/h;

Example: The extractor fan needed for a Kitchen

  • Volume: 2.8 x 2.8 x 2.8 22m3;
  • Number of Air Changes Required: 10;
  • Performance: 22 x 10 220m3/h;
  • Fan required: Manrose WF150A 220m3/h;

Minimum Air Changes Required Per Hour for specific rooms

  • Bathroom & Shower Rooms: 3 air changes required;
  • Bedrooms: 2 air changes required;
  • Cafés: 10 air changes required;
  • Canteens: 8 air changes required;
  • Cellars: 3 air changes required;
  • Changing Rooms with Showers: 15 air changes required;
  • Conference Rooms: 8 air changes required;
  • Garages: 6 air changes required;
  • Hairdressing Salons: 10 air changes required;
  • Halls & Landings: 3 air changes required;
  • Hospital Rooms: 4 air changes required;
  • Kitchen – Domestic: 10 air changes required;
  • Laundries & Launderettes: 10 air changes required;
  • Living & other Domestic Rooms: 3 air changes required;
  • Meeting Rooms: 4 air changes required;
  • Offices: 6 air changes required;
  • Restaurants & Bars: 6 air changes required;
  • School Rooms: 2 air changes required;
  • Shops: 8 air changes required;
  • Sports Facilities: 6 air changes required;
  • Store Room: 3 air changes required;
  • Toilets – Domestic: 3 air changes required;
  • Toilets – Public: 10 air changes required;
  • Utility Rooms: 15 air changes required;
  • Workshops: 6 air changes required;

Manrose Extractor Fan Models

  • Standard Manrose Extractor Fans – For remote switching through wall light or separate switch(ex. Manrose XF1).
  • Timer model Manrose Extractor Fans – with built-in adjustable time delay operated by the light switch(ex. Manrose CF200T).
  • Pullcord model Manrose Extractor Fans – with built-in pullcord switch(ex: Manrose XF100P).
  • Humidity controlled models Manrose Extractor Fans – with built-in adjustable sensor which operates the fan automatically(ex. Manrose XF100H).
  • P.I.R. model Manrose Extractor Fans – sensitive to movement Switches on when room is entered and off when room is vacated(ex. Manrose XF100PIR).

  • Axial Manrose Extractor Fans: are designed to move air over short distances i.e. window fixing or through mounting and are not suitable for ducting over 2 metres in length. Available in 4″, 5″, 6″, 9″ and 12″ sizes.
  • Centrifugal Manrose Extractor Fans – are designed to move air over longer distances and will perform well against the pressure caused by long lengths of ducting and resistance by grilles.
    N.B. When ducting vertically it is recommended that a condensation trap is used.
  • Humidistat Controls Manrose Extractor Fans: Manrose have a complete range of integral Humidistat Controls on all their fans, they are also available with a pullcord the bathroom and off as it falls.
    It will continue to monitor the humidity 24 hours per day, thus preventing mould growth on walls and ceilings and drastically reduces condensation problems.

Stale air is also removed by installing the appropriate Manrose fan. In certain circumstances, such as toilets, a timer is incorporated to provide an automatic turn-on period of 15 minutes as stipulated in The Building Regulations. Read more about the Manrose Extractor Fans via the Articles about Heating & Ventilation, or purchase online the Manrose range of Domestic / Commercial fans.

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