This paper describes the use of tracer-gas techniques to measure airflow in a rectangular duct and a HVAC system. Experimental procedures are discussed for the application of the constant injection, pulse injection and decay techniques using N2O andSF6 as tracer gases. This paper also describes a new tracer-gas system with variable sampling speed which was used to measure the decay of tracer-gas concentration. A comparison is presented between tracer-gas measurements and those made with a pitot tube and a hot wire anemometer.
In the framework of a CEC-DGXVII demonstration project a hygroregulating natural ventilation system is being evaluated in 52 occupied apartments. Therefore a multi purpose automated tracer gas equipment has been developed enabling the detailed monitoring of air flow rates in 60 rooms continuously. In addition the humidity levels, CO2 levels and air temperatures are measured as well as the outdoor climate. The first measurement campaigns partly used for evaluation of the measurement system are reported and show an impressive amount of data enabling various types of detailed analysis.
This paper describes the activity on Air Infiltration and Ventilation of the research group of "Dipartimento di Energetica" in Politecnico of Turin. The group formed in 1988 and only at the beginning of 1990 it began to work on multizone flow analysis. The aim of the group is to set up an apparatus for air infiltration measurement comparable to those of other countries; up to now only measurements using decay technique were made in laboratory in a scale-model which represents a two-zone system.
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