Optimizing the effective conductivity and cost of gas-filled panel thermal insulations

Abstract

Gas-Filled Panels, or GFPs, are an advanced thermal insulation that employ a low-conductivity, inert gas, at atmospheric pressure, within a multilayer reflective baffle.The thermal performance of GFPs varies with gas conductivity, overall panel thickness, and baffle construction.Design parameters of baffle constructions that have a strong effect on GFP thermal resistance are (1) cavities per thickness, (2) cavity surface emittance, and (3) conductance ofthe baffle materials.GFP thermal performances, where the above parameters were varied, were modeled on a spreadsheet by iterative calculation of one-dimensional energy balances.Heat flow meter apparatus measurements of prototype GFP effective conductivities have been made and are compared to results of the calculations.The costs associated with varying baffle constructions are estimated based on the prices of commercial material components.Results are presented in terms of cost per area per unit thermal resistance ($/AreaR-Value) and are useful for optimizing GFP designs for air, argon, or krypton gas :fills and a desired effective conductivity and thickness.