Effects of clothing's thermal insulation on outdoor thermal comfort and thermal sensation: A case study in Tehran, Iran

Abstract

The objective of this research is to examine how clothing insulation value (Icl) impacts outdoor thermal comfort and sensation (TSV), suggest changes to the physiologically equivalent temperature (PET) and universal thermal climate index (UTCI) measures to account for these effects, and reconsider Icl benchmarks. Research included on-site measurements in Tehran, Iran, and 838 interviews. The analysis found a significant difference in thermal comfort levels between TSV and PET, with 77.3 % of cases indicating comfort temperature. However, when comparing TSV with UTCI, this percentage slightly decreased to 75.5 %. In equations involving PET and Icl, the coefficient for males was 0.74 for Icl and 0.12 for PET, while for females, it was -0.32 for Icl and 0.1 for PET. Similarly, in equations involving UTCI and Icl, the coefficient for males was 0.92 for Icl and 0.13 for UTCI, while for females, it was -0.06 for Icl and 0.1 for UTCI. These results highlight the effects of Icl and thermal conditions on thermal sensation for genders, with females experiencing lower PET and UTCI values than males. Additionally, the outcomes of the study, which involved adjusting the indices (PETIcl / UTCI Icl) to consider Icl, will aid in creating outdoor spaces that are more pleasant and comfortable.