Minimize thermal edge losses with stainless steel envelopes for Vacuum Insulation Panels (VIPs)

Vacuum Insulation Panels (VIPs) traditionally maintain a reduced pressure in their interior by surrounding a core with an inexpensive laminate of a polymer film with a 7.6 urn thick aluminum film, or a more expensive polymer film coated with ~0.3 m thick aluminum film. In either case the VIP is too fragile to be attached directly to a building's envelope without utilizing a mechanical superstructure, and thermal edge losses of the superstructure can dramatically reduce the high R value offered by a VIP. We show that commercially available 51 n thick stainless steel foil has the strength to be attached directly to a building's envelope without a superstructure, is relatively impermeable, and has edge losses between that of an inexpensive laminate and the coated film. We use a finite difference method to estimate how low the edge losses can be reduced. The economic justification for this reduction diminishes after achieving ~85% of the maximum R value for an infinite pane l that would not have any edge losses.