The B&ES DW144 specification defines standards for sheet metal ductwork design, materials, construction, and testing for low to high pressure air systems.
The DW144 specification, published by the Building & Engineering Services Association, provides the industry standard for sheet metal ductwork used in low, medium and high pressure/velocity air systems. It outlines requirements for materials, classifications, air leakage limits and construction methods to ensure consistent quality and performance.
The document includes detailed sections on rectangular, circular and flat‑oval ductwork, component fastenings, hangers and supports, fire and smoke dampers, insulation, and testing procedures. Appendices give guidance on air‑leakage testing, galvanising, material grades and regulatory compliance.
It covers standards for sheet metal ductwork for low, medium and high pressure/velocity air systems.
The specification is published by the Building & Engineering Services Association (B&ES).
Copies are available from B&ES Publications, Old Mansion House, Eamont Bridge, Penrith, Cumbria.