The constant tracer flow technique

Abstract This paper presents a simplified theoretical analysis of the constant tracer flow technique and a quantitative estimate of the accuracy when the ventilation air flow rate is constant. A system with a stable pressure regulator was used to keep the tracer gas flow rate constant. A bumber of tests were carried out in an unoccupied indoor test house with ventilation air flow rates known with an accuracy of 2%. The aim of the tests was to explore the effect of incomplete mixing, The tests were carried out both with and without artificial mixing. Simultaneous measurements were carried out with the constant concentration technique. Finally, the entires in the so-called τ-matrix were determined by moving the tracer gas source from room to room.