Central mechanical ventilation systems use air distribution systems to supply fresh, clean air to habitable rooms and extract stale, moist air from wet rooms. Mass flow ductwork is used to move large volumes of air between the terminals and the mechanical ventilation unit and between the mechanical ventilation unit and the manifolds of an air distribution system like Air Excellent. Aerfoam is not only very easy to install, it is also the only zero-carbon footprint insulated mass flow ductwork on the market. Its class D/ATC 2 airtightness, which is achieved by its airtight mechanical connections, minimises the fan energy use and sound production of mechanical ventilation units.