The draft standard AS 4254.1 Ductwork for air-handling systems in buildings, Part 1: Flexible duct is open for comment until November 18. The document provides standardised requirements for the performance testing, manufacture and installation of flexible ducts in order to improve their thermal performance. It is particularly relevant for specifiers, manufacturers, regulatory authorities and installers of air-handling systems for buildings. Independent market audits and studies in Australia and the USA have estimated thermal energy losses in the vicinity of 20 per cent to 40 per cent in flexible duct systems due to poor installation practices and insulation being thermally deficient for the application into which it is installed. The National Construction Code requires different thermal ratings for insulation used on flexible duct, depending on the climate zone and the application it is installed into. This, in conjunction with the increased energy efficiency requir...