Indoor air quality in naturally ventilated buildings in urban areas: case studies.

With environmental issues (such as high energy costs for air-conditioning and related C02 emissions and global warming) in mind, designers are increasingly considering natural ventilation as the primary design option. Naturally ventilated office buildings can typically consume less than half the delivered energy consumed in air-conditioned buildings representing cost-effective energy savings of the order of 20-30%. In this paper results will be presented of measurements of the internal climate in two naturally ventilated office buildings located near major roads where atmospheric pollution and noise levels are perceived to be high. Results of levels of typical air pollutants such as carbon monoxide, nitrogen dioxide and sulphur dioxide and of noise levels are presented and compared with air quality guidelines and standards. Ventilation rates within the building and external wind speed and direction are also given to allow the pollution measurements to be put into context. An initial analysis of the ventilation strategies used in mitigating the effect of external pollution is made and initial conclusions drawn for future guidance.