Polyurethane and phenolic insulation panels (pre-insulated air ducts)

Polyurethane and phenolic insulation panels (pre-insulated air ducts)

Traditionally, air ductwork is made of sheet metal which is installed first and then lagged with insulation. However, ductwork manufactured from rigid insulation panels does not need any further insulation and can be installed in a single step. Both polyurethane and phenolic foam panels are manufactured with factory applied aluminium facings on both sides. The thickness of the aluminium foil can vary from 25 micrometres for indoor use to 200 micrometres for external use or for higher mechanical characteristics.

There are various types of rigid polyurethane foam panels available, including a water formulated panel for which the foaming process is obtained through the use of water and CO₂ instead of CFC, HCFC, HFC and HC gasses. Most manufacturers of rigid polyurethane or phenolic foam panels use pentane as foaming agent instead of the aforementioned gasses.

A rigid phenolic insulation ductwork system is listed as a class 1^{[clarification needed]} air duct to UL 181 Standard for Safety.