 Vent- Axia Air Changes Per Hour
The points which affect this are:
| a.
| the size of the building or room
|
| b.
| the purpose for which it is used
|
| c.
| the number of occupants
|
| d.
| the type of work they are doing
|
| e.
| heat gains from other sources, e.g., electric motors and equipment
|
| f.
| the amount of steam, dust and odours from production processes
|
| g.
| whether the customer has any particular temperature requirement for the building
|
The table of recommended ACH given in information leaflets, and the more extensive and detailed list given for different types of rooms and buildings is based on a combination of practical experience and theory, and can safely be used as a guide for all normal conditions in this country.
The figures should be doubled for work in hot climates or situations, and increased by 50% if there is a possibility of much tobacco smoke.
How to calculate the number of Ventilation units required for a room:
= |
Volume of room in m³ × ACH required
Volume of air moved by one unit in m³/h |
| e.g. |
A workshop 25 × 10 × 4.5m requiring 8 ACH |
| |
Number of 300mm impeller units: |
25 × 10 × 4.5 × 8
1415 (medium speed) |
= 6.4 (say 6) |
| |
This would be increased to 7 if Roof Mounted fans were used due to the lower output (1305 m³/h on medium speed). |
|
