Experimental and numerical study on heating performance of the mass and thin concrete radiant floors with ground source systems

The thickness of the slabs is imperative when considering the method of heating system due to the thermal mass and thermal lag properties. Thermal properties of concrete allow thermal energy to be stored in the mass floor after heating cycles. In this study, the experimental heating performance of a 1.22 m-thick mass concrete radiant floor and a 0.18 m-thick concrete floor is investigated. In addition, a full 3D finite element model of the mass concrete radiant floor is performed and validated by the full-scale building measurements. The mass floor simulation contains embedded pipes, vertical steel anchors, and horizontal reinforcing steel grids at the top and bottom. The experimental results show that the initial temperature of the thick concrete slab is increased by a few cycles and the mass heated concrete floor acts as a thermal storage battery for the building. Also, the modeling results are in good agreement with construction site measurement. This model is further expanded to simulate different thermal loadings on the pipes to predict the temperature development inside of the mass floor. Furthermore, importance of the vertical steel anchors in conduction the generated heat to the surface of the floor would be seen in the modeling results.