Thermal Performance Evaluation of an Innovative Double Glazing Window

The paper presents the results of the numerical simulations of the conjugate heat transfer process in an innovative double glazing window, represented as a vertical cavity filled with air and equipped with internal transversal. Numerical simulations were performed by a commercial CFD code (Fluent v6.3) varying both the Rayleigh number and the aspect ratio of the cavity. The heat transfer effects of the air flow inside the cavities were estimated both at the onset of convective flows and at working conditions of real systems. The work is aimed to calculate local and global Nusselt numbers for different configurations of the air cavity, which are needed to apply the standard heat loss estimation method to such modified double glazing windows. The thermal performances of the systems were also characterised in terms of an efficiency parameter.