Offering the same great vinyl cladded protection as rectangular Thermaduct, Thermaround is an excellent solution for the outdoor elements. This high R-value system offers an R-12 insulated value and extremely low air leakage. Thermaround uses same UV stable 1000 micron vinyl cladding for a durable solution that will naturally shed water. In the interior, air passes over a smooth aluminum surface free from loose fibers to give your building better IAQ performance.