US Patent 9163397 Foil-backed wallboard and insulation system

An insulated exterior wall assembly combining insulating material and reflective surface insulation coupled with an air gap. A wall assembly according to this invention includes wall support studs defining insulation cavities between them, sheathing boards facing the building exterior, an insulating material such as cellular plastic material or fibrous insulation applied from the exterior sheathing partly through the depth of the insulation cavities, a foil-backed gypsum-containing wallboard applied to the interior facing portions of the studs, with an air gap between the foil backing of the wallboards and the surface of the foam along the depth of the studs. The wall assembly according to this invention provides comparable thermal resistance compared to a deep layer of insulating material.