The use of occupant-exhaled CO₂ as the tracer gas enables the actual indoor infiltration rate to be measured, but the number and location of measuring points have a great impact on the accuracy of the results. This paper compares the experimental results from two tracer gas measurement techniques, decay with SF₆ and constant injection with CO₂ (exhaled by occupant). The results show a deviation of –9.0 to 7.4% between these two methods. This paper compares the result of this study with previous ones, and it confirmed that the CO₂ method is an effective technique to calculate the infiltration rate in a room with a certain air volume when one measuring point is provided, and this is more accurate with good mixing of the indoor air. The impact of the measurement duration and distribution of indoor air on the measurement accuracy are also analysed. It is found that an extended monitoring period can reduce the impact of indoor air distribution. In actual measurements in residential building, it is recommended to select the data after occupants have been in the room for half an hour and to take measurements over 1 h after that.

Practical application: Accurate air change per hour (ACH) is beneficial to the study of building energy consumption and indoor air quality. This paper explores the effectiveness of CO₂ method, which provides useful reference for the large sample measurements of infiltration rates in residential buildings.

使用乘员呼出的CO ₂作为示踪气体可以测量实际的室内渗透率，但是测量点的数量和位置对结果的准确性有很大的影响。本文比较了两种示踪气体测量技术的实验结果，两种测量技术分别为：SF ₆衰减和CO ₂恒定注入（由乘员呼出）。结果表明这两种方法之间的偏差为–9.0到7.4％。本文将这项研究的结果与以前的研究结果进行了比较，并证实了CO ₂当设置一个测量点时，该方法是一种计算具有一定风量的房间中的渗透率的有效技术，并且在室内空气良好混合的情况下，这种方法更加准确。还分析了测量持续时间和室内空气分布对测量精度的影响。发现延长的监视时间可以减少室内空气分配的影响。在住宅建筑中进行实际测量时，建议在居住者待在房间半小时后选择数据，然后在1小时内进行测量。

实际应用：每小时准确的换气量（ACH）有助于研究建筑能耗和室内空气质量。本文探讨了CO ₂方法的有效性，该方法可为住宅建筑渗透率的大样本测量提供有用的参考。