A numerical calculation procedure for an air flow window (AFW) system integrated with a roll screen is presented. Both beat and air flows within the window elements such as the outside pane of glass the outside air space, a venetian blind, the inside air space and a roll screen, are taken into account by considering the thermal and air flow networks. Agreements between measured and calculated results of temperatures and pressure differences through a series of experiments carried out in an environmental test chamber were observed.

The application of computer tools in construction is set for a revolution as integrated software packages come close to fruition. But there are barriers to the increased use of electronic design tools, notably worries over validation, the skills needed both in the design studio and on site and the quality assurance issues of correctly defining product elements and the design criteria. Over the next three articles, we examine the potential for using integrated computer design tools.

Windows are where we often look to improve the energy performance in old homes. But don't rip out those old sashes yet. A field study in Vermont suggests that "remove and replace" is not necessarily the way to go when it comes to old windows.

BRE has developed a new technique for measuring time-averaged ventilation rates in occupied buildings using a perfluorocarbon tracer gas. It was conceived as a way of solving the problems which arise when conventional tracer gas techniques are used in large or multi-roomed buildings. Potentially, the new technique will allow routine performance monitoring of both natural ventilation and forced air supply systems, thereby helping users to save energy and to meet the health, safety and comfort requirements of the building's occupants.