Equivalent area

Domestic Ventilation Compliance Guide, 2010 Edition (with 2011 amendments), published by the Department for Communities and Local Government in July 2011, suggests that equivalent area is: ‘…a measure of the aerodynamic performance of a ventilator. It is the area of a sharp-edged circular orifice which air would pass through at the same volume flow rate, under an identical applied pressure difference, as the opening under consideration.’

Approved Document O: Overheating, published by HM Government in 2021, defines equivalent area as: ‘A measure of the aerodynamic performance of an opening. It is the area of a sharp-edged circular orifice through which air would pass at the same volume flow rate, under an identical applied pressure difference, as through the opening under consideration.’

See also: Effective area.

[edit] Related articles on Designing Buildings

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• Free area.
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