On the estimation of the radiant heating surface temperature and the heat transfer rate calculation: New transient simplified analytical model

In this paper, a new semi-analytical model based on a hybrid approach that combines a numerical approach and a sensitivity analysis is developed to evaluate the surface temperature of the underfloor heating system and analyse its thermal behaviour under transient conditions. The model is validated by measurements which are performed in a full-scale test cell. Furthermore, a good agreement is obtained by comparing the developed semi-analytical model with two multidimensional numerical models based on the finite difference method and the finite volume method that are previously developed. The sensitivity analysis, based on the Design of experiments method, indicated that the most influencing parameters on the thermal response of the heating slab, are respectively the specific heat capacity and the heating water flowrate.