Tracer gas test

This paper describes the ongoing development of a new tracer gas test (TGT) for total air change rates measurement. This new TGT, intended for use in large-scale IAQ assessments and based on constant tracer injection, 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 along with commonly assessed VOCs using a commercial passive IAQ sampler. Via literature study and lab testing, decane-D22 was found to be a suitable tracer substance.

The placement of mobile air cleaners (MACs) in classrooms was widely discussed between parents, teachers, and authorities in Germany during the peak of Corona infections in 2020 and 2021. Measurements of mobile air cleaner efficiencies in larger laboratory rooms indicated that there are substantial efficiency differences between test re-sults in a real room compared to results measured in a standardized 28m³ well-mixed clean test room according to a standard. The test method described here overcomes the multiple problems and uncertainties of aerosol particle decay tests.

By 2050, the European council proposed to achieve total decarbonization in buildings. In this way, building energy models are key factors to predict the energy consumption in the design, use and retrofit stages. However, these models may present a relevant gap between predicted and measured energy performance, which should be minimised by cutting uncertainties with real data. Air leakage is one of the main uncertainties and causes of increasing building loads by renovating the indoor air in an uncontrolled way.

Ventilation is critical in interpreting indoor air quality (IAQ), yet few IAQ assessments report ventilation rates; even when they do, the measurement method is often not fully described. Most ventilation assessments use a tracer gas test (TGT) to measure total air change rate. In a TGT, the indoor air is marked with an easily identifiable gas (tracer) so that the air change rate can be inferred by monitoring the tracer’s injection rate and concentration.

Ventilation is critical in interpreting indoor air quality (IAQ), yet few IAQ assessments report ventilation rates; even when they do, the measurement method is often not fully described. Most ventilation assessments use a tracer gas test (TGT) to measure total air change rate. In a TGT, the indoor air is marked with an easily identifiable gas (tracer) so that the air exchange rate can be inferred by monitoring the tracer’s injection rate and concentration.

Ventilation of buildings and homes is a key issue both from comfort and energy aspects. However to determine the average ventilation air flow or the Air Change Rate (ACH) for a heating season by tests in case of natural ventilation, involve certain difficulties. Essential requirements when testing a physical phenomenon: