Have a question in regards to an attic mounted horizontal gas furnace and evap coil. Attic is ventilated and considered unconditioned space. Have been systematically replacing the old R-4 flex duct with R-8 along with upgrading the attic insulation to R-38+. Is there any product on the market that can be used to insulate the outside of the furnace case and the cased coil in order to minimize temperature losses or gains through these cabinets? Is there any data to support or disprove this?