Analysis of Natural Convection and Heat Transfer for Traditional Box Type Windows

This paper gives a detailed description of the thermal behavior of box type windows (BTW), in particular the air flow characteristic inside and through the window. The thermal and flow behavior is influenced by climate conditions (e.g. solar radiation, wind speed, ambient temperature) as well as the geometry of the window. The results of in-situ measurement and monitoring of two identically constructed historic box type windows, differently refurbished, have been used to validate the outcome of two-dimensional Computational Fluid Dynamics (CFD) simulations, to reproduce the effects of heat transfer, buoyancy driven air flow, radiation and solar heating for the window and the environment nearby the window. Furthermore this paper includes consideration of two different climate conditions as well as an investigation of the effect of a low-emission coating for the window panes