Despite this, spiral ducts have presented somewhat of a challenge when it comes to using a duct liner insulation. Unlike rectangular ducts, that offer a flat surface that the insulation can be pinned ...

The vast majority of installations specifying flexible closed-cell elastomeric duct liner have been for traditional rectangular duct. But liner is being used on spiral duct HVAC construction projects.

Based on JM’s proprietary fiberglass board technology, Spiracoustic Plus duct liner has factory-made, evenly spaced kerfs to allow the material to conform to the inside diameter of spiral ducts.