A New Method for Indoor Air Measurement

Chamber, Air duct, and test house experiments were carried out in order to characterize performance of a new “green” air tracing technology. Chamber experiments measured tracer broadcast control and safety. Sensor experiments tested multi instrument precision and tracer-sensor performance in ducts and ambient space. Building experiments included air change rate measurements using both the new tracer and sulfur hexafluoride (SF6) tracer. In-duct ventilation air supply ratio was measured in real time using sensors located before and after the mixed air supply. Three-hour and 18-hour room measurements showed greater decay of LIPA tracer versus SF6. PID measurements showed good agreement between multiple continuous reading sensors over these time periods. Good safety, broadcast control, real-time sensing, and multi-sensor precision were demonstrated. The strengths of this new method over previous tracer technologies demonstrated in these experiments include the ability to rapidly measure changes in labeled air levels in real-time, using relatively low cost sensing instruments. Examples of uses for real-time air tracing include commissioning, test and balance air distribution systems and ventilation effectiveness surveys, as well as verifying exhaust systems performance and air leakage testing.