High R super insulation panel

An insulation panel comprising a predominant amount of mineral fibers in the form of a mineral fiber board having a density of between 8 and 28 pounds per cubic foot, the fibers having no organic binder thereon, and amorphous silica powder packed in the interstices of the board, the fibers having a diameter between 1 and 25 microns, the particulate material being between 5 and 40 percent by weight of the combined mineral fibers and particulate material, and the amorphous silica having a surface area of at least 150 square meters per gram, and a gas-tight envelope encapsulating the board, the envelope being evacuated to a vacuum between 10.sup.-4 Torr and 10 Torr.

An insulation panel comprising a predominant amount of mineral fibers in the form of a mineral fiber board, the fibers having no organic binder thereon, and particulate material packed in the interstices of the board, the fibers having a diameter between 1 and 25 microns, the particulate material being between 5 and 40 percent by weight of the combined mineral fibers and particulate material, and the particulate material having a surface area of at least 50 square meters per gram, where the density of mineral fibers within the panel is sufficient to block a substantial portion of the radiation heat transfer, and the particulate material is sufficient to block a substantial portion of the heat transfer by gas conduction.