Estimating local thermal insulation of clothing garments: Modelling and application

Clothing influences the heat exchange between the human body and the environment, and the thermal resistance of clothing is typically unevenly distributed across different body parts. The determination of local clothing insulation is critical for the operation of multi-segment human thermoregulation models to obtain accurate thermophysiological parameters. As current standards only consider overall clothing insulation for the whole body, it remains difficult to estimate local clothing insulation in field studies and human experiments. In this study, a method for estimating the local thermal insulation values of garments using their overall insulation values was proposed, and its practical application for determining local insulation of ensembles was further presented. Eight garment types for gender-neutral and male garments (excluding female-specific garments such as skirts and bras) were classified according to the main covered area of the human body. Based on the thermal manikin test results of 75 garments, prediction models for local insulation at different body parts were developed for various types of garments using the overall insulation values. For practical applications, the estimation method was applied to typical garments in the ISO 7730 standard to obtain reference local insulation values. The local insulation of ensembles can finally be calculated by combining the regression models between the local insulation of the ensemble and the sum of the local insulation of the contained garments. This study can help to determine standardized local clothing insulation, providing validated input parameters for heat transfer analysis of the human-clothing-environment system and local thermal comfort research.