Free area
Domestic Ventilation Compliance Guide, 2010 Edition (with 2011 amendments), published by the Department for Communities and Local Government in July 2011, suggests that the term ‘free area’ refers to: ‘…the geometric open area of a ventilator of terminal.’
Approved Document O: Overheating, published by HM Government in 2021, defines free area as: ‘The geometric open area of a ventilation opening. This area assumes a clear sharp-edged orifice that would have a coefficient of discharge (Cd) of 0.62.’
Approved document F: Volume 1: Dwellings, 2021 edition, defines free area as: ‘The geometric open area of a ventilator.’
see also Equivalent area and Discharge coefficients, free, effective and equivalent areas
[edit] Related articles on Designing Buildings
- Air change rates.
- Approved Document F.
- Background ventilator.
- Cross ventilation.
- Discharge coefficients, free, effective and equivalent areas.
- Displacement ventilation.
- Equivalent area.
- Heat recovery ventilation.
- Mechanical ventilation.
- Natural ventilation.
- Stack effect.
- Thermal comfort.
- Underfloor air distribution.
- Ventilation.
- Whole building ventilation.
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