A study comparing the effectiveness (as reported by occupants) of passive stack ventilation (PSY) and mechanical extract fans (MEFs) was carried out during the winter of 1996. This involved a face-to-face survey of 437 homes in England. More than 50% of the homes in the study had MEFs, 14% had PSV and 8% had humidistat-controlled MEFs (HMEFs). About 25% of the homes had either a kitchen or a bathroom with no ventilation device and 16% had no ventilation device in the home.

The propagation of low-amplitude air pressure transients within the drainage and vent systems of underground habitable structures may result in system failure due to trap seal loss and foul odour ingress into the occupied space. This paper develops the simulation of such transient response, and presents comparisons between predicted system air pressures and those monitored during the operation of the drainage and vent system in a large London Underground tube railway station.

A cautionary tale of what happens when the entire construction and development system breaks down.

Describes the development of the Swedish duct tightness guidelines, the "AMA system". The latest version, due in 1998, aims to increase tightness requirements once again by introducing a tightness class D as the standard requirement for larger spiroduct systems. The concern about an increasing part of the Swedish population becoming allergic and asthmatic led to the Swedish Parliament introducing compulsory inspections of ventilation systems in 1990.