The correct size, type and number of Vent-Axia units required for any area is determined by three factors: the room size, its use and location.
First, work out the volume of the room by multiplying length × width × height. This volume is then multiplied by the required number of air changes per hour (ACH) given in the table to provide the total number of airmovements required per hour. Select the number of fans necessary to achieve the desired volume.
The new Building Regulations require the following ventilation rates on new dwellings:
Kitchen areas:
an extract rate of no less than 216m³/h (60l/s). For calculation purposes we recommend an air change rate of 15 per hour.
Utility rooms:
an extract rate of no less than 108m³/h (30l/s). For calculation purposes we recommend an air change rate of 15 per hour.
Bathrooms:
an extract rate of no less than 54m³/h (15l/s). For calculation purposes we recommend an air change rate of 6 per hour.
The new requirements are designed to remove steam and smells at source before they are able to migrate and cause damage to colder parts of the dwelling.
This table provides suggested air changes per hour (ACH) under normal conditions based on Vent-Axia's extensive experience.
| Assembley Halls | 4-8
| Hospitals | - Sterilising | 15-25
| | Bakeries | 20-30 | | - Wards | 6-8
| | Banks | 4-8 | Kitchens | - Domestic | 15-20
| | Bathrooms | 6-10 | | - Commercial | 20-30 Min
| | Battery Charging Rooms | 6-8 | Laboratories | 6-15
| | Bedrooms | 2-4 | Laundrettes | 10-15
| | Billiard Rooms * | 6-8 | Laundries | 10-30
| | Boiler Rooms | 15-30 | Lavatories | 6-15
| | Cafes & Coffee Bars | 10-12 | Lecture Theatres | 5-8
| | Canteens | 8-12 | Libraries | 3-5
| | Cellars | 3-10 | Living Rooms | 3-6
| | Churches | 1-3 | Mushrooms Houses | 6-10
| | Cinemas & Theatres * | 10-15 | Offices | 6-10
| | Club Room * | 10-12 | Paint Shops (not cellulose) | 10-20
| | Compressor Rooms | 10-20 | Photo & X-ray dark rooms | 10-15
| | Dairies | 8-10 | Public House bars | 10-15
| | Dance Halls * | 8-12 | Recording studios | 10-12
| | Dye Works | 20-30 | Recording Control rooms | 12-25
| | Electroplating Shops | 10-12 | Restaurants | 8-12
| | Engine Rooms | 15-30 | Schoolrooms | 5-7
| | Entrance Halls, Corridors | 3-5 | Shops & Showrooms | 8-12
| | Factories & Workshops | 8-10 | Shower Baths | 15-20
| | Foundries | 15-30 | Stores & Warehouses | 3-6
| | Garages | 6-8 | Swimming Baths | 10-15
| | Glasshouses | 25-60 | Toilets | 6-10
| | Hairdressing salons | 10-15 | Welding Shops | 15-30
| | * Increase by 50% where heavy smoking occurs, or if the room is underground
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