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Ventilation for Work in Confined Spaces.
School of Public Health, The University of Michigan, Ann Arbor, Michigan 1991 Mar:72 pages
A series of studies was conducted involving experimental testing and computer modeling to evaluate ventilation characteristics and improve design methods for confined spaces (CS). The models were developed in an effort to predict CS ventilation effectiveness and to advance ventilation design technology. Multicellular models of CS ventilation were programmed and tested for two basic variations. Model 1 used experimental data and approximations to represent airflow in the CS. Model 2 used airflow characteristics predicted by another computer model. Mechanical ventilation was far more effective than natural ventilation could have been in CS. In general supply ventilation was more effective than exhaust ventilation. The inlet/outlet elevation had a significant effect on effectiveness with low inlet/outlet elevations being generally more effective in diluting contaminants. Ventilation time decreased with increasing flow rate, but not usually in a linear manner. Significant, variable, and somewhat inconsistent effects on ventilation time were observed by changing the CS model shape. Ventilation effectiveness characteristics varied significantly with contaminant stratification caused by heavier than air contaminants. Dilution ventilation characteristics for simulated toxic concentrations were similar to those for oxygen deficiency caused by nitrogen (7727379).
NIOSH-Grant; Control-technology; Tunneling; Ventilation-systems; Confined-spaces; Air-quality-control; Air-quality-monitoring; Sewer-cleaning; Miners;
Environmental & Indust Health University of Michigan 1420 Washington Heights Ann Arbor, MI 48109-2029
Final Grant Report;
NTIS Accession No.
Control Technology and Personal Protective Equipment; Research Tools and Approaches; Control-technology;
School of Public Health, The University of Michigan, Ann Arbor, Michigan
University of Michigan at Ann Arbor, Ann Arbor, Michigan
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division