Ducts Buried in Attic Insulation and Encapsulated Description Guide describing approaches to burying and encapsulating ducts in unconditioned attics to increase the overall R-value of duct insulation.
Encapsulated Ducts Description Guide that illustrates how and when to encapsulate ductwork in unconditioned attics, increases the R-value of duct insulation, mitigating condensation issues and reducing air leakage.