Numerical study of thermal comfort and energy efficiency about electrically heated footwear under a cold environment

Abstract

Purpose

The paper aims to reveal the relationship among energy efficiency, thermal comfort and thermal regulation of electrically heated footwear and to investigate influencing factors on the energy efficiency and thermal comfort.

Design/methodology/approach

A finite volume model was proposed to simulate the two-dimensional heat transfer in electrically heated footwear (EHF) under an extremely cold condition. The model domain consists of three-layer footwear materials, a heating pad, a sock material, an air gap and skin tissues. Model predictions were verified by experimental data from cold-contact exposure. Then the influencing factors on the energy efficiency and thermal comfort were investigated through parametric analysis.

Findings

The paper demonstrated that the skin temperature control (STC) mode provided superior thermal comfort compared to the heating pad temperature control (HPTC) mode. However, the energy efficiency for the HPTC mode with a heating temperature of 38 °C was 18% higher than the STC mode. The energy efficiency of EHF while reaching the state of thermal comfort was strongly determined by the arrangement and connection of heating elements, heating temperature, thickness and thermal conductivity of footwear materials.

Originality/value

The findings obtained in this paper can be used to engineer the EHF that provides optimal thermal comfort and energy efficiency in cold environments.

Citation

Su, Y., Wang, H., Liu, G., Wang, Y., Liu, J. and Tian, M. (2024), "Numerical study of thermal comfort and energy efficiency about electrically heated footwear under a cold environment", International Journal of Clothing Science and Technology, Vol. 36 No. 4, pp. 740-759. https://doi.org/10.1108/IJCST-06-2023-0094