Seasonal variations and the influence of ventilation rates on IAQ: A case study of five low-energy London apartments

Abstract

The indoor air quality (IAQ) of five low-energy London apartments has been assessed through the measurement of 16 key pollutants, using continuous and diffusive methods across heating and non-heating seasons. This case study approach aimed to assess the presence of pollutants within low-energy apartments and to better understand the role of ventilation and seasonal variations in indoor air quality. The results indicate strong seasonal variations, driven by increased natural ventilation rates over the summer monitoring period. A combined metric for indoor and outdoor pollutants ( Itot) suggests that the IAQ in the winter ( Itot = 17.7) is more than twice as bad as that seen in the summer ( Itot = 8.6). Formaldehyde concentrations were lower in the non-heating season, indicating increased ventilation rates more than offset increased off-gassing, in contrast to findings in other studies. However, increased summertime ventilation rates were observed to increase the proportion of outdoor pollutants entering the internal environment. This resulted in higher indoor concentrations of NO2 in the summer than the winter, despite significant reductions in outdoor concentrations. These results demonstrate the impact of ventilation practices upon IAQ, the influence of occupant actions and the complex relationship ventilation rates play in balancing indoor and outdoor sources of air pollution.

The Variability of Indoor Air Pollutants in the Office and Their Impact on the Workers’ Health

“…In contrast, they revealed significantly higher levels in the winter months, with concentrations peaking at 15.3 µg/m 3 for the corridor and 17.6 µg/m 3 for the bathroom. The consistent findings extend to environmental monitoring in English homes, revealing a notable trend of formaldehyde concentrations decreasing by half from winter to summer [59]. The variation in trends between the office and other rooms may be attributed to disparities in ventilation systems.…”

Airborne bacterial and PM characterization in intensive care units: correlations with physical control parameters

“…Both Chamseddine et al ( 2019 ) and Zaman et al ( 2021 ) offered possible explanations for these seasonal variations; both cited that increased indoor activity during the cold season increased the rate of pollutants influx, ultimately causing the observed surges in concentrations. It should be noted that the impact of seasonality on indoor air quality is not limited to the hospital setting; several studies have reported similar observations for residential settings (Abdel-Salam 2021 ) and in learning institutions (Deng and Lau 2019 ; Stamp et al 2022 ). In comparison, the spatial variability of microorganism levels in hospitals remains less studied.…”

Investigation of thermal comfort and adaptation among the residents of cold climate in the lower Himalayan region of eastern India

“…Apart from the comfort, air velocity could also affect the indoor air quality. 1,51 However, due to the absence of fans, very few instances were seen when there was significant air velocity around subjects and in most cases, the anemometer with a low resolution (0.1 m/s) returned zero reading showing the presence of still air condition. Nicol and Humphreys 48 further states that even at still air condition, due to convection current and bodily movement, there could be some air velocity relative to the human body, and thus cannot be treated as zero.…”