Abstract

This paper describes the development of a new adaptation of the traditional tracer gas test (TGT) used for total air change rates (ACH) measurement. This adapted TGT, based on constant tracer injection, is intended for use in large-scale IAQ assessments and employs an alternative tracer gas that is more adequate than the currently employed SF₆ and perfluorocarbons, and that can be co-captured and co-analyzed with commonly assessed VOCs by commercial passive IAQ-sampling. As it is based on passive sampling, the proposed TGT yields long-term integrated ACH values, and is thus indicated only for studies focused on characterizations based on average estimations rather than on analyses requiring fine temporal resolution. By means of literature study and lab experiments, decane-D₂₂ was selected as a suitable tracer substance. The selected tracer was shown not to adhere/absorb significantly to surfaces. A passive source of decane-D₂₂ was selected and optimized in lab, providing stable and repeatable emission rates unaffected by varying RH and ACH. An exponential prediction curve was derived for determining the source emission rate from the average room temperature. Moreover, a range of adequate levels of liquid tracer inside the source is suggested. A successful field test application for validation of the new TGT is also described.

摘要

本文描述了用于总空气变化率 (ACH) 测量的传统示踪气体测试 (TGT) 的新改编开发。这种基于恒定示踪剂注入的改编 TGT 旨在用于大规模 IAQ 评估，并采用比目前使用的 SF ₆和全氟化碳更合适的替代示踪气体，并且可以共同捕获和共同分析通过商业被动室内空气质量采样通常评估的 VOC。由于它基于被动采样，因此建议的 TGT 产生长期综合 ACH 值，因此仅适用于基于平均估计的表征研究，而不是需要精细时间分辨率的分析。通过文献研究和实验室实验，癸烷-D ₂₂被选为合适的示踪物质。显示出所选示踪剂不会明显粘附/吸收到表面。在实验室中选择并优化了癸烷-D _{22 的}被动源，可提供稳定且可重复的发射率，而不受 RH 和 ACH 变化的影响。导出指数预测曲线，用于根据平均室温确定源排放率。此外，建议在源内放置一定范围的足够水平的液体示踪剂。还描述了用于验证新 TGT 的成功现场测试应用程序。