Please note that this is a scanned copy of a paper originally published in 1995, so the text is not as clear as in documents created as pdf files.

BRE has developed a new technique for measuring time-averaged ventilation rates in occupied buildings using a perfluorocarbon tracer gas. The new technique has the potential to 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. 4 pages.