Long-term, continuous air quality monitoring in a cross-sectional study of three UK non-domestic buildings. (August 2020)

• Record Type: Journal Article
• Authors: Stamp, Samuel; Burman, Esfand; Shrubsole, Clive; Chatzidiakou, Lia; Mumovic, Dejan; Davies, Mike
• Is Part Of: Building and environment. Volume 180(2020)
• Publication Date: 2020-08
• Subjects: Indoor air quality -- Case study -- Field Measurements -- Ventilation rates -- Indoor-outdoor ratio -- Building Operation; Buildings -- Environmental engineering -- Periodicals; Building -- Research -- Periodicals; Constructions -- Technique de l'environnement -- Périodiques; Electronic journals; 696
• DOI: 10.1016/j.buildenv.2020.107071
• Languages: English
• ISSNs: 0360-1323

Abstract

Abstract: Long-term, continuous air quality monitoring has been carried out alongside seasonal passive sampling within a case study a hospital, school and office building, representing a cross-section of the UK non-domestic sector. This approach aimed at adopting state of the art sensor technology to provide a greater understanding of the variations in indoor air quality over time and how these variations relate to both building operation and occupant behavior. The results highlight how the relationship between indoor and outdoor air evolves considerably on both short and long-term basis, with varying behaviors then seen across different sources of pollutants. The mechanically ventilated hospital and school buildings demonstrate the effectiveness of particulate filters, with very low internal concentrations of PM2.5 . However, high ventilation rates, combined with the absence of any filtration of NO2, resulted in the hospital having the highest indoor concentrations of NO2 and the highest associated indoor-outdoor ratio. Morning and evening traffic related peaks in NO2 can be observed indoors, with their penetration dependent upon the delivered ventilation rates. This demonstrates the impact of adopting high ventilation rates during peak traffic, and the consequences of CO2 based demand-controlled ventilation systems in polluted urban areas without full filtration. The naturally ventilated office then demonstrates significant seasonal variations, with increased ventilation openings resulting in indoor NO2 concentrations in the summer exceeding those in the winter, despite significant reductions in ambient levels. Conversely, concentrations of indoor pollutants are seen to reduce with increasing ventilation rates, demonstrating the complex balance between the dilution of indoor pollutants and penetration of outdoor sources. Despite significant reductions from the winter to the summer (21.6–11.2 μg/m 3 ), all formaldehyde measurements in the naturally ventilated office exceeded guideline values, indicating improved guidance and product labelling schemes may be required to achieve these guideline concentrations and reduce associated health risks. Highlights: Long-term continuous and seasonal IAQ measurements in hospital, school and office. Mechanically ventilated buildings demonstrated effective particulate filtration. Absence of nitrogen dioxide filtration led to high indoor-outdoor ratios. Significant variation in indoor-outdoor ratios caused by increased ventilation. Measurements of benzene and several formaldehyde measurements exceeded guidelines.