基于大气PM2.5污染的建筑外窗缝隙通风换气次数动态变化特性

为了动态评价建筑外窗缝隙通风条件下室外PM_(2.5)污染对室内环境的影响规律及其渗透通风特性,依据研究团队2013年9月到2014年8月基于建筑外窗缝隙渗透通风(建筑外门窗关闭、无机械通风)且室内无污染源条件下关于北京地区某临街办公建筑室内外PM_(2.5)质量浓度水平与室外气象参数(空气干球温度、相对湿度、风速)的动态变化实时监测数据,结合质量平衡方程和数理统计方法提出了一种基于大量实测数据反演建筑外窗缝隙通风换气次数动态变化特性的评价模型,实测结果验证了该模型的有效性.研究结果表明:当建筑外窗结构特征和房间结构特征一定时(实测建筑穿透系数P为0.93±0.01、自然沉降率k为0.10±0.03),静稳天气时的建筑外窗缝隙通风换气次数平均值约为0.10 h-1,对应的室内外PM_(2.5)质量浓度比I/O约为0.43;微风天气时的平均值约为0.22h-1,对应的I/O约为0.56;和风天气时的平均值约为0.39 h-1,对应的I/O约为0.62.研究结果可为室内人群健康风险评估以及建筑室内通风净化系统优化设计与节能运行提供重要参考.

Dynamic Characteristics in Air Infiltration Rate With Respect to Atmospheric PM2.5 Pollution

The window cracks is one of the important passageway that atmospheric fine particulate matter (PM2.5) get through into the indoor environment and then causing the indoor personal PM2.5 exposure.In order to evaluate the characteristics of air infiltration through the window cracks,a longitudinal monitoring regarding both indoor and outdoor PM2.5 mass concentrations and meteorological parameters (e.g.temperature,wind speed and relative humidity) were carried out in an unoccupied office located in Beijing from September 2013 to August 2014,with the condition of no mechanical ventilation and no indoor PM2.5 pollution sources.Additionally,a mathematical model of air infiltration rate based on a large number of measured data combined with mass conservation theorem and the method of mathematical statistics was developed.The results show that the outdoor weather conditions and atmospheric PM2.5 concentrations is the important factor of the air infiltration rate in a room which has a certain window structure (the PM2.5 penetration factor (P) is O.93 ± O.01 and deposition rate (k) is 0.10 _± 0.03 for the sampling site).Influenced by the change of the outdoor wind speed,the average air infiltration rate is about 0.10 h-1 at static stability days,and it is about 0.22 h-1 at gentle breeze days,as well as 0.39 h-1 at moderate breeze days.