Evacuated panels are one possible alternative to chlorofluorocarbon blown rigid polyurethane foam as thermal insulation. These panels are covered with a vacuum tight foil to sustain the required vacuum, which influences performance. To evaluate the effective thermal conductivity, calculations on the total heat transfer of both metal-free and fully metal-coated vacuum panels were performed. These panels or walls containing a vacuum panel were applied in air and it turned out that different boundary conditions can have a remarkable effect, we employed boundary condi tions of the third kind including heat transfer coefficients of 6 W m-2 K-1 and 12 W m-2 K-1, respectively.
