LAUSR

Abstract The local and mobile incident sunlight from skylight and side windows shining on the floor surface increases the cooling capacity of the radiant floor cooling system. In this study, a novel method of homogenizing spatial solar radiation distribution over the entire radiant floor surface is proposed to the design of the radiant floor with a conventional circuit pattern of counter flow. A verified three-dimensional numerical radiant floor model is utilized to evaluate the deviation of the novel method in steady and transient states. The simulation results indicate that the relative error for local sunlight with a width over two pipe spacing is less than 1.0%. With a solar radiation intensity of 300 W/m2, the deviation of the simulated floor surface heat flux via the novel method is less than 0.3 W/m2 for any sunlight size in steady states. Furthermore, under transient and mobile sunlight, the simulated water side and floor surface heat fluxes via the novel method agrees well with the 3D model. As a result, the homogenizing treatment significantly simplifies the dynamic analysis of radiant floor system under temporal and spatial solar radiation distribution with enough accuracy in engineering applications.