The occupants of six houses suffered from symptoms which improved upon leaving their houses. In a previous study, tests were conducted in these six houses to measure various physical parameters related to their indoor environments. Four of these houses were subsequently renovated to improve indoor air quality. Tests were repeated on the four houses to assess the effectiveness of the applied remedial measures.

This paper examines three different ventilation strategies aimed at reducing the indoor concentration of traffic pollutants by ventilation control. In the strategies the air change rate is adjusted in response to (a) the outdoor concentration of the pollutant (single-sensor strategy), (b) the outdoor and indoor concentration (double-sensor strategy) and (c) the time of the day (peak-period strategy). A double sensor was found to be twice as effective as the single sensor, reducing the mean indoor concentration of carbon monoxide by 34% over a 48-hour period.

Indoor and outdoor concentrations of respirable particulates and sulfates have been measured in 68 homes in six cities for at least 1 yr. A conservation of mass model was derived describing indoor concentrations in terms of outdoor concentrations, infiltration and indoor sources. The measured data were analysed to identify important building characteristics and to quantify their effect. The mean infiltration rate of outdoor fine particulates was found to be approximately 70 %- Cigarette smqking was found to be the dominant indoor source of respirable particulates.

This review examines the available information relating to the ingress of external pollutants into naturally ventilated buildings. It is part of a project whose longer term aim is to provide guidance on ventilation strategies for naturally ventilated buildings in polluted urban areas. The purpose of the review is to guide this project.

The ventilation effectiveness concept has been extensively used in research, where it has long been recognised as a good indicator of air quality. Also, there are many examples of its parameters having been measured as an aid to monitoring the air quality in completed buildings, usually to solve an air quality problem. However, despite their value as a predictor of the air quality to be achieved by an air distribution system, ventilation effectiveness parameters are rarely used in design.

The ventilation in Norwegian residences was studied with respect to the effect of new standards, construction techniques adopted, and energy conservation measures implemented  This was compared to residential ventilation performance in other countries with a similar climate. The effective total air change rate (h-1) in 344 residences was measured with a passive tracer gas method known as the perfluorocarbon tracer gas method (PFT-method). The measurements were performed over a 14-day integrated sampling period.

mechanical ventilation is needed to avoid indoor air quality problems. Many new conventional houses have low natural air change rates ...... and are tight enough to require mechanical ventilation, but most have none.