Results from a validated CFD simulation of a supply air "ventilated" window.

A currently unresolved problem in building design is the paradox between increasing demand for good thermal insulation, and the requirement for ample levels of ventilation, to maintain a healthy indoor environment. A possible solution to this problem is a supply air 'ventilated' window. This utilises an airflow between panes to pre-heat ventilation air to the building, and to reduce thermal convection losses, thus reducing the window Ue-Value. A 2D Computational Fluid Dynamics (CFD) model has been built and validated to analyse the performance of the window under various conditions, including different glass types, configurations and ventilation. The simulated behaviour of the window under these conditions is shown, including it's thermal insulation properties and ability to pre-heat ventilation air to the building, and the factors affecting it's performance discussed. The results show that a very low Ve-Values of the order of 0.2 are possible with even simplistic double paned designs. Finally the simulation is used to optimise the design of window, with cost considerations included.