Foam Duct

Foam MVHR ducting for mass air flow has many benefits:

Smooth interior walls needed for low noise and reduced energy use.
Easy to fit together.
Pre-insulated – 16-44mm with a thermal conductivity as low as 0.030W/mK
Prevents condensation from forming on the outside of the duct between the unit and exterior.
Used to transport air from the wall/roof terminals to the MVHR unit and from the MVHR unit to the distribution boxes.