Distributions of Local Supply and Exhaust Effectiveness according to Room Airflow Patterns

  • Han, Hwa-Taik (Department of Mechanical and Automotive Engineering, Kookmin University) ;
  • Choi, Sun-Ho (Graduate School, Kookmin University) ;
  • Lee, Woo-Won (Graduate School, Kookmin University)
  • Published : 2002.12.01

Abstract

A pulsed tracer gas technique is applied to measure the distributions of local mean age and local mean residual-life-time of air in a half-scale experimental chamber, The airflow patterns in the chamber are visualized by a Helium bubble generator for three different exhaust locations. A supply slot is located at the top of a right wall, and an exhaust slot is at either bottom-left (Case 1), bottom-right (Case 2), or top-left (Case 3) location. Results show that the distributions of local mean age and local mean residual-life-time are different from each other, but both of them are closely related to the airflow pattern in the space. Included are discussions on explaining the variations of overall room ventilation effectiveness depending upon airflow rates for three different supply-exhaust configurations.

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References

  1. Yaglou, C. P. and Witheridge, W. N., 1937, Ventilation Requirements, ASHVE Trans., Vol. 42, pp. 423-436
  2. Sandberg, M. and Sjoberg, M., 1983, The Use of Moments for Assessing Air Quality in Ventilated Rooms, Building and Environment, Vol. 18, No. 4, pp.181-197
  3. ASHRAE, 1997, ASHRAE Handbook- Fundamentals, American Society of Heating, Refrigerating, and Air-Conditioning Engineers
  4. ASHRAE, 1997, Measuring Air-Change Effectiveness, ANSI/ASHRAE 129-1997, American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Atlanta
  5. Han, H., 1992, Numerical Analysis of Ventilation Effectiveness using Turbulent Airflow Modeling, Proc. of Int. Symp. on Room Air Convection and Ventilation Effectiveness, pp. 187-191
  6. Faulkner, D., Fisk, W. J., Sullivan, D. P. and Wyon, D. P., 1999, Ventilation efficiencies of Desk-Mounted Task/Ambient Conditioning Systems, Indoor Air, Vol. 9, No. 4, pp. 273-281
  7. Han, H., Kuehn, T. H. and Kim, Y. I., 1999, Local Mean Age Measurements for Heating, Cooling, and Isothermal Supply Air Conditions, ASHRAE Trans., Vol. 105, Pt. 2, pp. 275-282