Reflectix Duct Insulation is an alternative to other types of fibrous insulation products. Ease of handling and quick installation make Reflectix the first choice when selecting insulation for round or rectangular ductwork in HVAC systems. The product provides an R-6.0 or R-8.0 when installed with a 0.75? air gap between the duct and the insulation. There is a choice of three spacer configurations that create the required air space.