%0 Journal Article
%A Max H Sherman
%B Review of Scientific Instruments
%D 1990
%G eng
%N 9
%P 2457-2461
%T A Multi-Tracer System for Multizone Ventilation Measurements
%V 61
%2 LBL-29010
%8 01/1990
%X <p>Mass transfer due to pressure-driven air flow is one of the most important processes for determining<br />both environmental quality and energy requirements in buildings. Heat, moisture, and<br />contaminants are all transported by air movement between indoors and outdoors as well as<br />between different zones within a building. Measutement of these air flows are critical to understanding<br />the performance of buildings. Virtually all measurements of ventilation are made using<br />the dilution of a tracer gas. The vast majority of such measurements have been made in a single<br />zone, using a single tracer gas. For the past several years LBL has been developing the MultiTracer<br />Measurement System (MTMS) to provide full multizone air flow information in an accurate,<br />real-time manner. MTMS is based on a quadrupole mass spectrometer to provide highspeed<br />concentration analysis of multiple tracer gasses in the (low) ppm level which are injected<br />into multiple zones using mass flow controllers. The measurement and injection system is controlled<br />by a PC and can measure all concentrations in all zones (and adjust the injected tracer<br />flows) within two minutes and can operate unattended for weeks. The resulting injection-rate<br />and concentration data can be analyzed to infer the bulk air movement between zones. The system<br />also measures related quantities such as weather and zonal temperature to assist in the data<br />interpretation. Using MTMS field measurements have been made for the past two years.</p>