Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, FR, Italy.
Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, FR, Italy.
Sci Total Environ. 2017 Oct 1;595:894-902. doi: 10.1016/j.scitotenv.2017.03.048. Epub 2017 Apr 19.
In order to reduce children's exposure to pollutants in classrooms a proper ventilation strategy need to be adopted. Such strategy is even more important in naturally ventilated schools where the air exchange rate is only based on the manual airing of classrooms. The present work aimed to evaluate the effect of the manual airing strategy on indoor air quality in Italian classrooms. For this aim, schools located in the Central Italy were investigated. Indoor air quality was studied in terms of CO, particle number and PM concentrations and compared to corresponding outdoor levels. In particular two experimental analyses were performed: i) a comparison between heating and non heating season in different schools; ii) an evaluation of the effect of scheduled airing periods on the dilution of indoor-generated pollutants and the penetration of outdoor-generated ones. In particular, different airing procedures, i.e. different window opening periods (5 to 20min per hour) were imposed and controlled through contacts installed on classroom windows and doors. Results revealed that the airing strategy differently affect the several pollutants detected in indoors depending on their size, origin and dynamics. Longer airing periods may result in reduced indoor CO concentrations and, similarly, other gaseous indoor-generated pollutants. Simultaneously, higher ultrafine particle (and other vehicular-related pollutants) levels in indoors were measured due to infiltration from outdoors. Finally, a negligible effect of the manual airing on PM levels in classroom was detected. Therefore, a simultaneous reduction in concentration levels for all the pollutant metrics in classrooms cannot be obtained just relying upon air permeability of the building envelope and manual airing of the classrooms.
为了减少儿童在教室中接触污染物，需要采取适当的通风策略。在自然通风的学校中，这种策略更为重要，因为空气交换率仅基于教室的手动通风。本工作旨在评估手动通风策略对意大利教室室内空气质量的影响。为此，对位于意大利中部的学校进行了调查。室内空气质量研究了 CO、颗粒物数和 PM 浓度，并与相应的室外水平进行了比较。特别是进行了两项实验分析：i）在不同学校比较供暖和非供暖季节；ii）评估定期通风期对室内产生的污染物稀释和室外产生的污染物渗透的影响。特别是，通过安装在教室门窗上的触点，施加并控制不同的通风程序，即不同的开窗时间（每小时 5 至 20 分钟）。结果表明，通风策略根据其大小、来源和动态，不同程度地影响室内检测到的几种污染物。较长的通风时间可能会降低室内 CO 浓度，同样也会降低其他室内产生的气态污染物。同时，由于从室外渗透，室内测量到更高的超细颗粒（和其他与车辆相关的污染物）水平。最后，检测到手动通风对教室中 PM 水平的影响可以忽略不计。因此，仅依靠建筑物围护结构的空气渗透性和教室的手动通风，无法同时降低教室中所有污染物指标的浓度水平。
