Coupled heat transfer through building components with air cavities

Heat transfer in building components with air cavities is considered, particular attention is given to walls of blocks with air cavities. A numerical procedure for thermal and fluid-dynamic calculations is presented for air cavities in conductive containment and horizontal heat flow. The proposed model is two-dimensional and considers conduction in boundary walls, convection within the cavities and direct radiation among solid surfaces on the cavity boundary. The numerical model calculates the overall heat transfer in PVC components with air cavities in the same conditions of experiments performed in a guarded hot plate apparatus. Experimental results are compared to numerical ones and to values provided by European and Italian standards.