National Ventilation FXALINS Insulated Flexible Ducting is specially designed for the HVAC market. The FXALINS range has been developed to minimise the heat gain or loss resulting from the temperature differential between the air flow and the surrounding ambient air. The vapour barrier prevents condensation forming on the outside of ducts carrying air at lower temperatures than the surrounding air. Aluminium reinforced multi-ply flexible duct wrapped in a 25mm high-density fibreglass for excellent friction loss characteristics and reduced levels of noise generation.