A C02 concentration of more than 1000 ppm has been monitored in Taiwanese bedrooms during sleeping hours in the wintertime. The high indoor C02 levels were caused by poor ventilation due to insufficient ventilation rates. This study sought to reduce the wintertime C02 concentration level in a typical Taiwanese bedroom with less outdoor air to maintain thermal comfort. C02 was used as an indicator to assess whether an adequate ventilation rate has been obtained to dilute or remove harmful pollutants.

With sensor-based demand-controlled ventilation ( SBDCV), the rate of ventilation is modulated over time based on the signals from indoor air pollutant or occupancy sensors. SBDCV offers two potential advantages: better control of indoor pollutant concentrations, mid lower energy use and peak energy demand.

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.