It contains minerals such as pyroxene, amphibole, feldspar and 63-68 percent silica. The eruption temperature for dacitic lava is 1,500 to 1,800 degrees Fahrenheit. Dacitic to rhyolitic lava is so dangerous because it contains a high amount of crystals.Mt. Vesuvius erupts according to the Plinian model of eruption.
Foil has low emissivity, so will greatly reduce radiative heat transfer (act like insulation). It should face the side that is supposed to be cooler. But foil will not reduce conductive heat transfer, so it must be used judiciously with something that reduces conduction.
Insulating HVAC Ductwork. When insulating HVAC ductwork, use a foil faced fiberglass insulation with an R-6 or higher R-value. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. Make sure the foil surface of the insulation is free of dust before applying the tape. Peel the paper backing off the tape as you apply it to prevent the tape from sticking to itself.