NIOSHTIC-2 Publications Search
Measuring indoor airflow patterns by using a sonic vector anemometer.
Yost MG; Spear RC
Am Ind Hyg Assoc J 1992 Nov; 53(11):677-680
The use of a novel instrument, a sonic vector anemometer, to measure indoor airflow patterns was described. The objective was to obtain velocity measurements that would provide qualitative information about the large scale flow pattern in a test room, as well as quantitative information on the amount of air movement and turbulence at various points in the room. A three component sonic anemometer which used ultrasound pulses to detect the air velocity components, and resolved the air velocity vector was used. Transducers provided digital and analog signals proportional to the velocity components along each of the three axes. Five minute sampling intervals were chosen to span at least four room time constants to ensure steady state flow conditions. Measurements over a 30 point grid were repeated a total of 12 times on 4 separate days. Results showed a substantial amount of turbulent energy at all points, with some points near the inlet having very high turbulence. The similarity of data obtained from the same locations at different times and on different days indicated that flow pattern and turbulence statistics remained stable. Analysis with the mapping program, VECMAP, generated directional plots of the flow field in a selected plane. VECMAP was capable of interpolating flow data between measured grid points and solid boundaries. Spot checks showed good agreement between measured and estimated values. An interpolated flow map was generated from averaged flow field data with velocity profiles at intervals of 2 feet along the horizontal axis. The vector diagram clearly showed a strong, high velocity "jet" tilting upward at the inlet accompanying highly turbulent recirculation zones located above and below. This jet gradually smoothed out to a uniform profile at a vertical height of about 9 feet. The authors conclude that the combination of anemometry and computer mapping offer insight into indoor airflows.
NIOSH-Publication; NIOSH-Grant; Grants-other; Air-flow; Air-monitoring; Analytical-instruments; Indoor-air-pollution; Industrial-environment; Industrial-hygiene; Pollution; Indoor-environmental-quality
Biomedical & Environ Hlth Scis University of California 322 Warren Hall Berkeley, Calif 94720
Issue of Publication
American Industrial Hygiene Association Journal
University of California Berkeley, Berkeley, California
Page last reviewed: September 22, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division