Flexible hoses in aluminium or plastic are mostly used for air distribution. Ducting can be bent easily so no elbows are needed. These hoses are delivered in one- or two-layer versions, with 25 cm thick insulation. As a NOVELTY we offer flexible, highly resistant PE ducting with antibacterial treatment and diameter DN 75.
An alternative solution is plastic ducting of 60x200 mm cross section. It is so flat that it can be installed even into constrained ceiling voids or floors. The plastic ducts are rigid so transitions are needed to change the direction or divide the air flow - bends or T-pieces. When installed into an unheated space (attic), additional insulation is needed.