Ventilation system designers may be guilty of professional negligence by working with inaccurate noise data and, even worse, they may be unwittingly causing Sick Building Syndrome. Ewen Rose reports

The need for individual control with manual overriding combined with controlled natural ventilation is discussed. It is made plausible that with these two facilities problems related with the Sick Building Syndrome can be avoided. This principle is applied in a so-call led passive climate system. A system is devised setting the level of heating and ventilation by controlling motors fitted to radiators, ventilation openings in windows, Venetian blinds and outside shading. Moreover, it will switch on the lighting when natural lighting is inadequate.

Statistics indicate that flying is the safest way to travet, but a trip on a ptane coutd be more hazardous to your health than you might imagine. Carolynne Dear reports.

Recent concern has centered on "sick buildings" in which there has been an unusually high percentage of health complaints by the building's occupants. Typically, these symptoms are thought to be tied to indoor air quality characteristics, such as high levels of respirable particles or volatiles, thermal conditions, etc. In addition, recent studies have drawn connections between "sick building syndrome" (SBS) symptoms and non-environmental variables, i.e., personal and occupational factors. This paper presents a brief review of a study by Hedge et al.

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.