Thermal discomfort inside building is due to outside climate, especially by excessive solar radiation during summer or by temperature drop during a cold season. The use of phase change materials (PCMs) can reduce this effect by storing heat transmitted by sensible and latent heat. This ensures good situation of thermal comfort throughout the year. In this work, thermal behavior of two roofing systems is studied. One roof that is taken as reference is constituted by usual materials in building. In the second, two PCMs are inserted according to three configurations. The objective of the study is to assess incorporation effect of two PCMs within reference roof and to evaluate the optimum locations to reduce the energy consumption of air-conditioned room. A monodimensional numerical model, validated analytically and experimentally, is used to carry out a parametric analysis to determine the characteristics of the PCMs to be used and their optimal location within the reference roof regardless of the external climate effect. Numerical calculations are performed for three configurations of roof with swapping PCMs. Results show that insertion of PCMs in the roof provides the best energy consumption saving regardless of annual climate change. Reduction in energy consumption of an air-conditioned room depends on the combination of PCMs, their mutual thicknesses, and thermal comfort level.

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The aim of this work is to study the combined insertion effect of Phase Change Materials (PCM) and thermal insulation within a partition wall separating a conditioned room from an adjacent local which is under a periodic thermal activity. This is done by a comparative study with a reference wall under the same thermal conditions. The comparison criterion is the energy density transmitted to the local conditioned in established regime. The results show that the inclusion of thermal insulation and phase change material provides a significant reduction of energy consumption of the conditioned local; thereby a judicious choice of phase change material with thermal level and range melting temperature reduces further this reduction.

Obviously, the outside annual climate change caused either by a major solar input during the hottest period or by a temperature drop during the coldest period leads to discomfort inside buildings. This effect can be reduced by storing heat transmitted in phase change materials (PCM) as latent heat, in order to ensure a good situation of thermal comfort during all months of the year. In this work, thermal behavior of two roofing systems is studied. One roof is constituted only by usual materials in building. In the other, two phase change materials (PCM) are introduced according to three configurations. Study is interested to assess incorporation effect of two PCMs within the roof and to evaluate the optimum locations to reduce the energy consumption of air-conditioned room. Mono-dimensional numerical model validated analytically and experimentally, is used to carry out a parametric analyzes to determine characteristics of the layers in which the roofs are formed regardless of external climate effect. Numerical calculations are performed for three configurations of roof. Results show that insertion of phase change materials in roof provides best energy consumption saving regardless annual climate change. Generally, the three configurations lead to different results, depending on the combination of PCMs. This difference becomes less important when selection of PCMs takes account the thermal comfort level and temperatures of hottest and coldest periods.