Optimization approach of passive cool skin technology application for the Building's exterior walls

Cool skin technologies, including high-reflective coating and vertical greening, are beneficial for passive energy-saving in buildings and are particularly useful in the renovation of existing buildings. Based on a numerical heat transfer model, a technology framework combining a multi-objective particle swarm optimization algorithm and a multiple criteria decision-making method, is proposed. The proposed method can rapidly determine the optimal application solution of cool skin technologies on a building's exterior walls. The optimal solution considers cost, energy-savings, and the environmental benefits. The technology framework has been explored in four typical cities in China using an office building as the prototype. The results demonstrate that, when comparing the performance of cool skin technologies, the differences in the wall orientations and the climate zones should be considered. Except for the buildings with winter heating demands in northern China, which should keep a bare wall in the south orientation, the prefabricated greening technology outperforms the climbing greening technology and the high-reflective coating technology in reducing the building cooling or heating load. With the geographical latitude decreases, the technical advantages of vertical greening become more significant. (C) 2020 Elsevier Ltd. All rights reserved.