Thermal performance evaluation of walls with gas-filled panel insulation

Gas-filled insulation panels (GFP), which were initially developed with a grant from the U.S. Department of Energy, are very lightweight and compact (when uninflated) advanced insulation products. GFPs consist of multiple layers of thin, low-emittance (low-e) metalized aluminum. When expanded, the internal, low-e aluminum layers form a honeycomb structure. These baffled polymer chambers are enveloped by a sealed barrier and filled with either air or a low-conductivity gas such as argon, krypton, or xenon. The sealed exterior aluminum foil barrier films provide thermal resistance, flammability protection, and properties to contain air or a low-conductivity inert gas. The unexpanded product is nearly flat for easy storage and transport. Therefore, the transportation volume and weight of the GFP needed to fill the volume of wall cavity is much smaller than that of conventional insulation products. This feature makes this product appealing to use at U.S. Army contingency and forward operating bases, where transportation costs are much higher than the cost of materials. This paper presents lab test results conducted in a rotatable guarded hotbox to evaluate the thermal performance of walls, similar to those used in typical barrack hut (B-hut) hard shelters, with GFPs in cavities. The test result show that while the effective surface-to surface thermal resistance (R-value) of the wall with two layers of GFP decreases sharply as the temperature of the GFPs increases, the R-value of the wall with only one layer of GFP remains fairly steady. That is because the R-value of 0.5 in. air space decreases and that of 1.5 in. air space increases as the mean temperature increases.