Using Orthogonal Expansion of Functions Over Multilayer Walls for Calculating the Layer Thermal Properties
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Vrachopoulos, M
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Antonopoulos, KA
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Tzivanidis, C
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An analytical method is presented for on-site estimation of the layer thermal properties of multilayer walls, based on separation of time and space variables, and on orthogonal expansion of functions over the multilayer walls. The advantage of the present method over previous analytical and numerical ones is that it requires temperature measurements on the outdoor and/or indoor wall surfaces, and not necessarily at locations within the wall, as previous procedures for multilayer walls do. The proposed method was tested theoretically and experimentally by applying it to multilayer walls of known properties. The agreement between calculated and known values was very good in all tests. The proposed method may be used for ex-post examination of structural materials used by a constructor, in analogous applications concerning archaeological monuments, and in the estimation of heating and cooling loads in old buildings with multilayer walls of unknown materials. The method may also be used in the design of special purpose buildings for selecting structural materials, which should meet certain temperature specifications. Copyright (C) 1996 Elsevier Science Ltd.
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