Investigating the effect of solar heat gain on intermittent operation characteristics of radiant cooling floor

Solar heat gain is an important part of the cooling load of a building, especially for a radiant cooling room. This study presents the development of a mathematical model based on the state-space method, which can consider the influence of dynamic solar heat gain on radiant cooling floor. The calculated results were consistent with the experimental data. The maximum relative error of each calculation time node of envelope and indoor air were within 7%, and that of floor surface temperature was 12.75%. Base on the model, the dynamic cooling performance of radiant floor under various conditions such as different filling layer thickness, building orientations, shading forms and operational modes were investigated. The results demonstrated that the intensity and time distribution of solar radiation exerted significant effects on the intermittent operational characteristics. Furthermore, the optimal selection of the radiant floor filler layer should be considered with operation mode. For the normal operation mode, the cooling performance of the floor with 50 mm filling layer was better than that of the floor with 100 mm filling layer. With regard to the pre-cooling mode, the cooling performance of the floor with 100 mm filling layer was excellent. The model can provide guidance for the design and operation of radiant cooling floor in different practical situations. (c) 2021 Elsevier B.V. All rights reserved.