Mechanical
Ventilation design
Natural, mechanical and mixed-mode ventilation design to Approved Document F or Technical Handbook Section 3, with calculated rates.
- Discipline
- Mechanical
WHAT IT IS
Ventilation design establishes how a building gets fresh air and removes stale air, moisture and pollutants — by natural means, mechanically, or a combination of the two.
Rates are calculated from occupancy, activity and pollutant load rather than taken from a default table, because the default is a floor and not a target. Where a building has a specific requirement — a commercial kitchen, a laboratory, a plant room with a refrigerant leak risk — that requirement drives the design.
WHEN YOU NEED IT
On every occupied building. Specifically where occupancy is changing, where a space is being converted to a different use, where indoor air quality is a stated requirement of the brief, or where a Part F or Section 3 compliance route must be demonstrated.
DELIVERABLES
What you receive
- Ventilation rate calculations
- Ductwork sizing and pressure drop calculations
- Air handling plant selection
- Ventilation drawings and schedules
- Commercial kitchen extract design where required
STANDARDS
Standards applied
The editions in force at the time of design. Where a standard is amended mid-project we confirm which edition the appointment is based on.
- Approved Document FVentilation (England)GOV.UK
- Technical Handbook Section 3Environment (Scotland)Scottish Government
- BS EN 16798-1:2019Indoor environmental input parametersBSI
- CIBSE Guide B2Ventilation and ductworkCIBSE
- BS EN 12097:2006Ventilation for buildings — ductwork — requirements for ductwork components to facilitate maintenance of ductwork systemsBSI
QUESTIONS
Common questions
How are ventilation rates calculated for a building?
Rates are calculated from occupancy, activity level and pollutant load, then checked against the minimum in Approved Document F in England and Wales, or Technical Handbook Section 3 in Scotland. Specific uses such as commercial kitchens and laboratories are designed to their own requirements, which are usually higher.