Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA.
School of Mechanical Engineering, Beijing Institute of Technology, Beijing, China.
Indoor Air. 2018 Jul;28(4):572-584. doi: 10.1111/ina.12462. Epub 2018 May 8.
Building ventilation rates and indoor airflow conditions influence occupants' exposure to indoor air pollutants. By making time- and space-resolved measurement of 3 inert tracers steadily released in a single-family house in California for 8 weeks in summer and 5 weeks in winter, this study quantifies the air change rate of the living zone with 2-hour time resolution; estimates airflow rates between the living zone, attic, and crawlspace; and characterizes mixing of air in the split-level living space. Occupant behaviors altered the air change rates, primarily through opening windows and secondarily through operating the heating system. The air change rate correlated with the number of window openings, accounting for 57% of the variability measured across 2 seasons. There were substantial upward interzonal airflows between the crawlspace, living zone, and attic; downward airflows were negligible by comparison. More than 70% of the airflow entering the living zone in the winter and at night during summer came through the crawlspace, rather than directly from outdoors. The airflow from the living zone to the attic increased with the attic-outdoor temperature difference, indicating that buoyancy associated with solar heating of the attic induced airflow from the living zone, increasing the air change rate.
建筑通风率和室内气流条件会影响居住者暴露于室内空气污染物的程度。本研究通过在加利福尼亚州的一栋独户住宅中持续 8 周夏季和 5 周冬季稳定释放 3 种惰性示踪剂，对其进行时间和空间分辨测量，以 2 小时的时间分辨率量化了居住区域的空气交换率；估计了居住区域、阁楼和爬行空间之间的气流速率；并描述了分层居住空间中空气的混合情况。居住者的行为改变了空气交换率，主要是通过打开窗户，其次是通过操作供暖系统。空气交换率与窗户开启数量相关，在两个季节的测量中占 57%的可变性。在爬行空间、居住区域和阁楼之间存在大量向上的区域间气流；相比之下，向下的气流可以忽略不计。在冬季和夏季夜间，超过 70%进入居住区域的气流是通过爬行空间进入的，而不是直接从室外进入的。冬季从居住区域流向阁楼的气流随着阁楼与室外的温差增加而增加，这表明与阁楼被太阳加热相关的浮力会引起从居住区域的空气流动，从而增加空气交换率。
