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Abstract

A laboratory appartus employing a trace gas technique has been developed to systematically study the effects of fabric and garment properties on microclimate ventilation in a simulated garment assembly. Nitrogen was used to flush the microcli mate enclosure, and the rate of atmospheric oxygen build-up in the system was traced. The gas exchange was assumed to have first-order kinetics. A new parameter, areal ventilation rate, that takes into account the microclimate volume and the fabric surface area, has been developed. External wind effects were simulated by conducting experiments in still air and in the presence of forced air flow. The results show that in still air, fabric air permeability has an insignificant effect on areal ventilation rate. However, with increasing external air flow, the effect of air permeability becomes more pronounced. Areal ventilation values are found to increase linearly with increasing external air velocities, and the influence of fabric constructional variables increase accordingly. The combined effects of permeability and air velocity on areal ventilation rate are interpreted in terms of a previously derived empirical equation. Simulation of garment openings did not have a significant effect on the ventilation rate, illustrating that small air passages are of less significance than flow through the fabric itself.

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References

"Annual Book of ASTM Standards, Part 32," American Society for Testing and Materials, Philadelphia, Pa. 1978, pp. 171-175, 380-382.

Crockford, G.W. , Crowder, M. , and Prestidge, S.P. , A Trace Gas Technique for Measuring Clothing Microclimate Air Exchange Rates, Brit. J. Ind. Med. 29, 378-386 (1972).

Crockford, G.W. and Rosenblum, H.A. , The Measurement of Clothing Microclimate Volume, Cloth. Res. J. 2, 109-115 (1974).

Fonseca, G.F. and Breckenridge, J.R. , Wind Penetration Through Fabric System. Part I, Textile Res. J. 35, 95-103 (1965).

Fourt, L. and Hollies, N.R.S. , "Clothing Comfort and Function," Marcel Dekker, New York, 1970, pp. 1-9, 150-154.

Gerrard, M. , Measurement of Ventilation Rates with Radioactive Tracers, ASHRAE J., Sept., 47-50 (1968).

Gregory, J. , in: E.R. Kraswell , "Textile Fibers Yarns and Fabrics," Reinhold, New York, 1953 pp. 224.

Hitchin, E.R. and Wilson, C.B. Investigation of Natural Ventilation in Buildings, Bldg. Sci. 2, 60-73 (1967/68).

Hoge, J.H. and Fonesca, G.F. The Thermal Conductivity of a Multilayer Sample of Underwear Material Under a Variety of Experimental Conditions, Textile Res. J. 34, 401-410 (1964).

10.

Hollies, N.R.S. , Fourt, K. , Arnold, G. , and Custer, N. , "Use Type Tests for Comfort and Effectiveness of Firemen's Turnout Coats," U. S. Dept. of Commerce, Contract No. NBS2-35929, 1973, pp. 18-26.

11.

Hunt, C.M. and Burch, D.M. , Air Infiltration Measurements in a Four-Bedroom Townhouse Using Sulfur Hexafluoride as a Tracer Gas, ASHRAE Trans. 81, 186-198 (1975).

12.

Kaswell, E.R. , "Wellington Sears Handbook of Industrial Textiles ," Wellington Sears, New York, 1963, pp. 451.

13.

Larose, P. , The Effect of Wind on the Thermal Resistance of Clothing with Special Reference to the Protection given by Coverall Fabrics of Various Permeabilities, Can. J. Res. 25, Sect. A, 169 (1947).

14.

Morris, M.A. , Thermal Insulation of Single and Multiple Layers of Fabrics, Textile Res. J. 25, 766-773 (1955).

15.

Niven, C.D. , The Heat Transmission of Fabric in Wind. Part I, Textile Res. J. 27, 808-811 ( 1957).

16.

Niven, C.D. , The Heat Transmission of Fabric in Wind. Part II, Textile Res. J. 29, 826-833 (1959).

17.

Prado, F. , Leonard, R.G. , and Goldschmidt, V.W. , Measurement of Infiltration in a Mobile Home , ASHRAE Trans. 82, 151-166 (1976).

18.

Rees, W.H. , The Transmission of Heat Through Textile Fabrics, J. Textile. Inst. 32, T149 (1941).

19.

Schiefer, H.F. , Advantages of a Blanket-and-Sheet Combination for Outdoor Use, J. Res. Nat. Bur. Stds. 30, 209 (1943).

20.

Shivers, J.L. , Yeh, K. , Fourt, L. , and Spivak, S.M. , The Effects of Design and Degree of Closure on Microclimate Air Exchange in Lightweight Cloth Coats, in: "Clothing Comfort," N. R. S. Hollies and R. F. Goldman (Eds.), Ann Arbor Science Publishers, 1977, pp. 167-181.

21.

Spencer-Smith, J.L. , The Physical Basis of Clothing Comfort, Part 3: Water Vapour Transfer Through Dry Clothing Assemblies, Cloth. Res. J. 5, 82-100 (1977).

22.

Tamura, G.T. and Wilson, A.G. , Air Leakage and Pressure Measurements on Two Occupied Houses, ASHRAE Trans. 70,110 (1976).

23.

Vokac, A. , Kopke, V. , and Keul, P. , Assessment and Analysis of the Bellows Ventilation of Clothing, Textile Res. J. 43, 474-482 (1973).

Applications of the Trace Gas Technique in Clothing Comfort

Abstract

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