Yuying An, Guangbiao Xu and Hua Shen
To have a better understanding of the heat transfer mechanisms in a sleeping bag and to investigate the factors influencing thermal resistance of a down sleeping bag.
Abstract
Purpose
To have a better understanding of the heat transfer mechanisms in a sleeping bag and to investigate the factors influencing thermal resistance of a down sleeping bag.
Design/methodology/approach
The mechanism of heat transfer in a sleeping bag was discussed in this paper. The thermal resistances of 24 samples were investigated. Besides, the relation between fill weight and thermal resistance, and that between the air permeability of fabric and thermal resistance, as well as that between down filling rate and thermal resistance were analyzed.
Findings
The results showed that thermal resistances of samples varied from 0.35 to 0.8 m2 K/W. The fill weight was the most important factor of thermal resistance of sleeping bag and the relation between fill weight and thermal resistance matched well with cubic function. A multiple regression formula was proposed, which with thermal resistance as a dependent variable and with air permeability of fabric, down filling rate, fill weight as independent variables.
Originality/value
Thermal properties of a sleeping bag were analyzed through simplified basic unit under simplified environment conditions, which was necessary for building the first stage of systematic study of thermal performance of a sleeping bag.
Details
Keywords
Yu-Ying An, Guangbiao Xu and Hua Shen
To understand the thermal insulation of four common structures of sleeping bags and factors influencing the thermal insulation as well as the thermal comfort of people who use…
Abstract
Purpose
To understand the thermal insulation of four common structures of sleeping bags and factors influencing the thermal insulation as well as the thermal comfort of people who use four kinds of sleeping bag structures.
Design/methodology/approach
Four samples corresponding to four common sleeping bag structures were made and their thermal properties were investigated through a combination of objective instrument measurement and subjective human subject tests.
Findings
The porosity of the samples and the length of the interlining had a main impact on the thermal resistances of the four sleeping bag structures. The thermal sensation ratings and the thermal resistances had good consistency. There was a strong correlation between human physiological parameters and thermal sensation evaluation. The male and female have significant differences in thermal sensation of different structures of sleeping bags.
Originality/value
Instrument measurement and human subject tests were combined to study the thermal properties of sleeping bag structures, which had little attention in the past in research fields.