England · Statutory guidance
Conservation of fuel and power: Approved Document L, Volume 2 — Buildings other than dwellings
Energy performance guidance for non-domestic buildings, covering fabric, services, controls and commissioning.
- Edition
- 2021 edition incorporating 2023 amendments · Volume 2; later editions and transitions on source page
- Search coverage
- 116 of 116 PDF pages · 2 OCR pages
Energy & sustainability
Open original PDF at page 73 Source wording and page order preserved. Drawings and table layouts remain available in the original PDF.
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Table 8.1 D uctwork pressure classes
Ductwork pressure class Design static pressure (Pa) Maximum air Air leakage limit (l/(s·m2)
velocity (m/s) of duct surface area)(1)
Maximum positive Maximum negative
Low pressure (class A) 500 500 10 0.027 ∆p0.65
Medium pressure (class B) 1000 750 20 0.009 ∆p0.65
High pressure (class C) 2000 750 40 0.003 ∆p0.65
High pressure (class D) 2000 750 40 0.001 ∆p0.65
NOTE:
1. ∆p is the differential pressure in pascals.
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Building Regulations 2010 Approved Document L Volume 2, 2021 edition
O N L I N E V E R S I O N
Edition and local adoption determine which requirements apply. Use the publisher’s document for the complete clauses, diagrams and amendments.