... airtight complex gluing. In between is aluminum alloy frame with drier, and air between the sheets is tight. ... heat conduction System, K value of single slice with thickness of 6mm glass is 5.75kcal/mh, ... --2.9kcal/mh, K value of hollow glass with Fluorine sulphur can drop to 1.19kcal/mh. ... in certain proportion. Sound insulation: Hollow glass filled with inert gas reduces 30 db of noise, and hollow ...