2007, Piran, Slovenia
Share Embed Flag
Download ePaper

2007, Piran, Slovenia

2007, Piran, Slovenia 2007, Piran, Slovenia

lboro.ac.uk
30.04.2013 Views

Environmental Ergonomics XII Igor B. Mekjavic, Stelios N. Kounalakis & Nigel A.S. Taylor (Eds.), © BIOMED, Ljubljana 2007 DISCUSSION Regional thermal comfort limit depends upon the location. In the whole body, thermal comfort sensation of the extremities is more sensitive than that of trunk. However, the thermal comfort of the whole body is not so much influenced by that of location in the experimental condition. Even though one feels locally thermal discomfort, its thermal comfort limit of the whole body is found to be 0.35 in terms of the skin wettedness. That is, the whole body can remain in thermally comfortable condition even when the skin wettedness stays lower than the comfort limit. ACKNOWLEDGEMENTS T Fukazawa is indebted to the Japanese Society for the Promotion of Science and the Ministry of Education, Culture, Sports, Science and Technology for financial support of this research. REFERENCES Gagge, A. P., Stolwijk, A. J. A., Nishi, Y., 1969. The prediction of thermal comfort when thermal equilibrium is maintained by sweating. ASHRAE Trans. 75, part II, 108-122. 374 Figure 3. Relation between thermal comfort sensation and local skin wettedness.

Thermal comfort THE EVALUATION OF THERMAL COMFORT FOR CB PROTECTIVE GARMENTS Y. W. Lin 1 , G. T. Jou 1 , G.H. Lin 1 , Y. C. Chang 1 , T.F. Lai 2 1 Taiwan Textile Research Institute, No.6, Chengtian Rd., Tucheng City, Taiwan (R.O.C) 2 Chung-Shan Institute of Science and Technology, Lung-Tan, Taiwan (R.O.C)) Contact person: gtJou.0219@ttri.org.tw INTRODUCTION Recently, the joint service lightweight integrated suit technology (JSLIST) garment has been widely adopted by the U.S. Army, Navy, Air Force, Marine Corps. This garment features not only chemical protection improvements, but also greater mobility, and heat stress reduction for the wearer.[1] To understand whether there is any difference among thermal comfort properties in the Taiwan climate, that could be described in objective way for the JSLIST garment, a battle dress overgarment (BDO) and an emergency chemical and biological (CB) suit, a series of experiments were conducted using a skin model system, sweating torso and sweating manikin. METHODS Skin Model System: According to ISO 11092, the test set the measuring plate at 35 and the air condition at 35 , 40% R.H. The air velocity was controlled at 1 m/s [2]. Sweating Torso System: The sweating torso system developed by EMPA Switzerland is a cylinder with the dimension of a human trunk [3]. The condition of the test using the torso is described in Table 1. To understand the thermal comfort of this clothing in Taiwan region, we measured with sweating torso system under condition similar to summer in Taiwan: 28 , 75% R.H. [4]. Table 1 Phase profile of sweating torso evaluation Phase and Period Moderate rate metabolic High metabolic rate 1 hour acclimatization Surface 35 Surface 35 1 hour sweating 82W, 100g/hr 118W, 300g/hr 1 hour recreation 23.5W 23.5W Sweating thermal manikin: 1 Measurement system: The thermal manikin called Huey was made by MTNW Company, designed with 1.75 m 2 surface area, 1.7 m height [5]. In this state, we analysed thermal resistance (R, clo) and the permeability index (im) of the 3 CB suits without consideration of the hands and face part of the manikin because there is no protective equipment on these areas in this study. The condition where the manikin stood was set to 28 , 75% R.H. as summer condition. 2 Evaluation method: According to Woodcock, A.H. works [6], dry heat transfer (HD) and evaporative heat transfer (HE) could be calculated by the following equations: 6. 45( TS Ta ) 2 H W/m .......... ......( 1 − = H D E = 14. 3 ( ) ) R × im × ( PS − Pa ) 2 ( W / m ) .......... ......( 2) R where: Ta and Pa stand for air temperature ( ) and water vapor pressure (mmHg), Ts and Ps are the temperature and water vapor pressure on the skin surface. 375

Environmental Ergonomics XII<br />

Igor B. Mekjavic, Stelios N. Kounalakis & Nigel A.S. Taylor (Eds.), © BIOMED, Ljubljana <strong>2007</strong><br />

DISCUSSION<br />

Regional thermal comfort limit depends upon the location. In the whole body, thermal<br />

comfort sensation of the extremities is more sensitive than that of trunk. However, the thermal<br />

comfort of the whole body is not so much influenced by that of location in the experimental<br />

condition. Even though one feels locally thermal discomfort, its thermal comfort limit of the<br />

whole body is found to be 0.35 in terms of the skin wettedness. That is, the whole body can<br />

remain in thermally comfortable condition even when the skin wettedness stays lower than<br />

the comfort limit.<br />

ACKNOWLEDGEMENTS<br />

T Fukazawa is indebted to the Japanese Society for the Promotion of Science and the Ministry<br />

of Education, Culture, Sports, Science and Technology for financial support of this research.<br />

REFERENCES<br />

Gagge, A. P., Stolwijk, A. J. A., Nishi, Y., 1969. The prediction of thermal comfort when<br />

thermal equilibrium is maintained by sweating. ASHRAE Trans. 75, part II, 108-122.<br />

374<br />

Figure 3. Relation between thermal comfort sensation and local skin wettedness.

logo

products

Resources

Company

Terms of service
Privacy policy
Cookie policy
Cookie settings
Imprint
Change language
Made with love in Switzerland
© 2024 Yumpu.com all rights reserved

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!