Vacuum insulated panel

A Vacuum Insulated Panel (VIP) uses the insulating effects of a vacuum to produce much higher R values than conventional insulation. Conventional insulation produces an R-value of eight or less per inch (fiberglass being towards the lower end and foam panels towards the higher end). VIPs are commonly as high as R-30 per inch, and have achieved commercially viable levels of R-50 per inch.

VIPs consist of:

Membrane walls, used to prevent air from getting into the vacuum area

Core material, used to hold the vacuum inside the membrane while preventing the membrane walls from collapsing

Chemicals to collect gases leaked through the membrane or offgassed from the membrane materials

The near-vacuum inside VIP's greatly reduces conduction and convection of heat. This is similar to the way in which a Dewar flask works, but without the reflective metal coatings. VIPs offer very high R-value by thickness (30-50R value per inch compared with 5-8R/in for various foams and a lower 2-3.54R/in for common fiberglass batting), but by cost and lifespan it is less competitive. Compared to more conventional insulating materials VIPs have a high cost/r-value ratio. Unlike fiberglass (although foam insulation does age), VIPs age as it is impossible to completely keep air from filling the vacuum. As the pressure of the panel normalizes with its surrounding air its R-value is deteriorated. Although their relatively higher cost compared with fiberglass and foam generally keep them out of traditional housing situations, their spectacular R/in values make them useful in situation where high insulation requirements or space constraints make traditional insulation impractical. (Foam sheets or batts are used over fiberglass often for the same goal of higher R/in, despite higher cost for the same R value)