Blog posts of '2026' 'July'

Air leakage can reduce ventilation performance, increase energy use and make systems harder to balance. This guide explains how DW/144 relates to ductwork leakage, sealing, pressure classes and testing.

DW/144 pressure classes determine how sheet metal ductwork should be constructed for different HVAC operating pressures. Learn about low, medium and high pressure ductwork, reinforcement, sealing and air leakage.

DW/144 is the recognised UK industry standard for the manufacture and installation of sheet metal ductwork used in commercial HVAC and ventilation systems. Published by BESA, it sets requirements for materials, construction methods, pressure classes, reinforcement and air leakage to ensure ductwork is manufactured safely, consistently and to a high standard. It is widely specified by consultants, contractors and building services engineers across commercial and industrial projects.