This paper provides projected area factors for each part of a sitting person to allow the radiative heat transfer between the human and surrounding surfaces to be calculated. We first briefly describe ways of calculating angle factors and effective radiation area for each segment of a sitting person. Then we describe an approach to measuring projected area factors using a manikin. Projected area factor distributions are presented, and then effective radiation area and angle factors are calculated and compared with the results of other studies.

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## Scholarly Works (7 results)

This paper provides projected area factor for each part of the human body to allow the radiative heat transfer between the human and surrounding surfaces to be calculated. We first describe ways of calculating angle factors, effective radiation area, radiative heat transfer coefficients, and the mean radiant temperature for each segment of the human body. Then we describe an approach to measuring projected area factors using a manikin. Projected area factor distributions and other important elements for radiation analysis are presented and compared with other studies.

The effects of air flow on clothing insulation and on the dry heat transfer coefficients were evaluated for each part of the clothed and nude human body. This was done by measuring clothing surface temperature using an infrared imaging radiometer. The results showed that increasing wind speed causes a decreased in clothing insulation and an increase in the dry heat transfer coefficients. The effects of air penetration on dry heat transfer coefficients could be determined by comparing the heat transfer coefficients of the clothed manikin to those of the nude manikin. Lastly, by comparing clothing insulation results obtained by the conventional indirect method of those of the direct method, in this study, one can demonstrated the limitation of the conventional method and the need for direct estimation.

Convective heat transfer coefficients for each part of the clothed human body were evaluated under airflow conditions and compared to those of nude body. This was done by measuring clothing surface temperatures on seated and standing manikin using an infrared-imaging radiometer. The convective heat transfer coefficients for the clothed manikin were larger than for the nude manikin. The difference could be 100 to 200% for some individual parts, and for the overall body the difference was 30 to 50%. These results were consistent for both standing and sitting postures, or for facing upwind and facing downstream, although slightly larger differences between clothed and nude could be seen when the manikin was sitting and facing upwind than in the other conditions. Clothing insulation for each part was also estimated. Some differences between standing and sitting were observed at the body part level. However for the whole body the difference was small. Regression models for convective heat transfer coefficients and clothing insulation for all body parts were presented for use in human thermal modeling.