A Parametric Analysis of the Thermal Performance of Concrete Floor Slabs in Cold Climates

The inherent thermal mass within the structural components of concrete buildings can have significant influence on energy efficiency in regard to heating and cooling in cold climates. Understanding the influence of building parameters on the passive storage of heat within heavy building materials is thus imperative when informing design decisions regarding energy efficiency. A parametric analysis was performed using energy modeling to characterize the thermal performance of concrete floor slabs in Toronto, Canada. Results showed that the most important factor influencing the relative performance of floor mass is the solar radiation transmitted through exterior glazing. The distribution of internal thermal mass and the density of internal gains were also found to be influential factors. Results were used to inform general concrete slab design guidelines for fully exploiting the thermal mass benefit by recommending minimum slab thicknesses. It is expected that in many cases, structural slab requirements will fulfill these recommendations.