北京地区办公建筑室内典型污染物日均浓度与工作时均浓度对比分析
Comparison of daily and working-time mean concentrations ofindoor typical pollutants in an office building in Beijing
摘要：
以办公建筑为代表的具有明确作息规律的建筑中,以污染物浓度24 h平均值作为室内污染物评价指标的合理性尚不清楚。本文以北京某办公建筑为对象,利用为期1个月的室内CO2和PM2.5浓度的实时监测数据,分析了24 h日均浓度和工作时均浓度(07：00—19：00)的关系。结果表明,对照我国GB/T 18883—2022,室内CO2和PM2.5日均浓度的超标率小于2%,但工作时均浓度的超标率远高于日均浓度(1.25～20倍)。日均浓度与工作时均浓度之间存在较大偏差,PM2.5相对偏差的最大值为0.45,中位值为0.14;CO2相对偏差的最大值为0.34,中位值为0.04。对照我国标准,室内CO2的漏判率为100%,错罚率为0;室内PM2.5的漏判率为62.3%,错罚率为19.7%。错罚率和漏判率与所采用的评价标准密切相关,随着浓度标准的提高,即浓度限值减小,错罚率和漏判率均下降。因此,针对实际办公建筑的空气质量评价,应当同时关注污染物的工作时均浓度而非仅采用24 h日均浓度,并选择合适的评价标准和浓度限值。本文的研究结果为更加准确、有效地评价办公建筑的空气质量评价提供了新思路。
Abstract：
The reasonability of using 24-hour mean pollutant concentration to evaluate the indoor air quality in the buildings with clear working schedules, as presented by office buildings, is not clear. Based on one-month real-time monitoring data of indoor CO2and PM2.5 concentrations in an office building located in Beijing, this paper investigates the correlation between the daily (24-hour) mean concentration and the working-time (07：00-19：00) mean concentration. The results show that the exceeding rates of indoor CO2and PM2.5 daily mean concentrations are less than 2% against the GB/T 18883-2022, but the exceeding rate of the working-time mean concentration is 1.25 to 20 times higher than that of the daily mean concentration. There is a large deviation between the daily mean value and the working-time mean value. The maximum value of PM2.5 relative deviation is 0.45, and the median value is 0.14. The maximum value of CO2relative deviation is 0.34, and the median value is 0.04. Compared to the Chinese standard, the probability of missed judgment of indoor CO2is 100%, while the probability of wrong penalty is 0. Similarly, the probability of missed judgment and wrong penalty of indoor PM2.5 is 62.3% and 19.7%, respectively. Moreover, the probabilities of wrong penalty and missed judgment are closely related to the evaluation standard, and decrease when the stricter standard with the smaller limit is applied. Thus, for the air quality evaluation of real office buildings, specific attention should be paid to the working-time mean pollutant concentration, and the appropriate evaluation standards as well as suitable concentration limits should be selected. The results provide a new perspective to accurately and effectively evaluate the air quality of office buildings.
Keywords:office building; indoor air quality (IAQ); evaluation indicator; CO2 concentration; PM2.5 concentration