Indoor air quality investigations in a naturally ventilated school building located close to an urban roadway in Chennai, India

2012 ◽  
Vol 54 ◽  
pp. 159-167 ◽  
Author(s):  
V.S. Chithra ◽  
S.M. Shiva Nagendra
2019 ◽  
Vol 43 (2) ◽  
pp. 121-142
Author(s):  
Andrea Ferrantelli ◽  
Camilla Vornanen-Winqvist ◽  
Milla Mattila ◽  
Heidi Salonen ◽  
Jarek Kurnitski

Moisture excess in buildings constitutes a complex problem affecting indoor air quality, energy consumption and the lifetime of the building envelope. We investigate the effect on moisture transfer in structures as a positive pressure is applied inside the enclosure. It is found that, contrary to established belief, the positive pressure does not induce any negative effects on the structures’ moisture content in normally ventilated classrooms, even with high occupancy. Our case study consists of a school building in Finland, subject to temperature and relative humidity measurements after a small (5–7 Pa) positive pressure was realized through ventilation control. We first address analytically the moisture excess generated inside the classrooms for 14 days, using dynamical balance equations that account for both ventilation effects and occupants’ moisture release in the environment. It is found that the average moisture excess is very small, largely below 1 g/m3, even for ventilation rates that are half the design value. We also examine the moisture performance of the envelope, by addressing the moisture migration at upper and lower joints of the external walls for both measured and design values of the indoor absolute humidity (AH). A coupled numerical model of diffusion and convection shows that moisture accumulation in the envelope and the according stresses are negligible for any realistic AH values. This result is in agreement with field measurements at the school. In conclusion, it seems that applying a small overpressure in a well-ventilated school building during a standard service period resulted in no accumulation inside the external walls, even at high occupancy and with low ventilation. Remarkably, it slightly dried out the moisture content in structures under actual occupancy conditions. The positive pressure has accordingly no negative effects on moisture performance, and is capable to guarantee a good indoor air quality as well.


2017 ◽  
Vol 132 ◽  
pp. 165-170 ◽  
Author(s):  
Camilla Vornanen-Winqvist ◽  
Sander Toomla ◽  
Kaiser Ahmed ◽  
Jarek Kurnitski ◽  
Raimo Mikkola ◽  
...  

Author(s):  
Camilla Vornanen-Winqvist ◽  
Kati Järvi ◽  
Sander Toomla ◽  
Kaiser Ahmed ◽  
Maria Andersson ◽  
...  

Author(s):  
Sandra E. Zaeh ◽  
Kirsten Koehler ◽  
Michelle N. Eakin ◽  
Christopher Wohn ◽  
Ike Diibor ◽  
...  

Children spend the majority of their time indoors, and a substantial portion of this time in the school environment. Air pollution has been shown to adversely impact lung development and has effects that extend beyond respiratory health. The goal of this study was to evaluate the indoor environment in public schools in the context of an ongoing urban renovation program to investigate the impact of school building renovation and replacement on indoor air quality. Indoor air quality (CO2, PM2.5, CO, and temperature) was assessed for two weeks during fall, winter, and spring seasons in 29 urban public schools between December 2015 and March 2020. Seven schools had pre- and post-renovation data available. Linear mixed models were used to examine changes in air quality outcomes by renovation status in the seven schools with pre- and post-renovation data. Prior to renovation, indoor CO measurements were within World Health Organization (WHO) guidelines, and indoor PM2.5 measurements rarely exceeded them. Within the seven schools with pre- and post-renovation data, over 30% of indoor CO2 measurements and over 50% of indoor temperatures exceeded recommended guidelines from the American Society of Heating, Refrigerating, and Air Conditioning Engineers. Following renovation, 10% of indoor CO2 measurements and 28% of indoor temperatures fell outside of the recommended ranges. Linear mixed models showed significant improvement in CO2, indoor PM2.5, and CO following school renovation. Even among schools that generally met recommendations on key guidelines, school renovation improved the indoor air quality. Our findings suggest that school renovation may benefit communities of children, particularly those in low-income areas with aging school infrastructure, through improvements in the indoor environment.


Author(s):  
Joan N. Parker ◽  
Mary Lee Dunn

While 31 million Americans have been diagnosed with asthma, children are most severely affected. Asthma also is common among teachers, indicating that the school building environment may be associated with asthma prevalence among occupants. Children are sensitive to environmental pollutants, which are more concentrated in indoor air environments. Schools are a significant source of indoor air pollutants. Yet little research has addressed the causal relationship between asthma and specific levels of indoor pollutants. Indoor air quality is seldom controlled in schools in a way that minimizes such exposures. While few laws limit indoor air pollutants in schools, some laws outline or mandate practices that can control exposures. This report presents recommendations for laws and regulations that control and, ideally, prevent indoor air quality problems and aims to reduce or mitigate such disease.


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