Standards Development

Scope

This document specifies the methodology of modeling human thermal sensation based on skin temperature in a moderate thermal environment, including data preparation for modeling, the method of modeling and model evaluation for human thermal sensation based on the skin temperature. It is intended for use in the design of new indoor and vehicle interior thermal environment, or the assessment of existing ones where thermal comfort is desirable and on the condition of no sweating for occupant, but where moderate deviations from thermal comfort occur.

Purpose

The purpose of this document is to provide reference for personalized control of indoor and vehicle interiors environments to improve individual thermal comfort by adapting environment conditions from an individual perspective, thereby matching personal cooling or heating needs.

This document covers the development of models for predicting of thermal sensation by considering individual thermal responses and measurements in moderate thermal environments, through specifying a methodology for predicting human thermal sensation based on skin temperature.

Human physiological parameters are significantly associated with autonomous thermoregulatory activities when exposed to thermal stimuli. The body skin temperature is one indicator of thermoregulation and the changes of skin temperatures can be associated with the human thermal sensation state.

A Thermal sensation model based on skin temperature establishes associations between skin temperature and thermal sensation vote. Local skin temperatures, either alone, combined with deviations in local skin temperature, or as mean skin temperature, can be selected to predict human thermal sensation. Incorporating biological characteristics (such as sex and body fat percentage), behaviors (e.g., clothing adjustment), psychological factors (e.g., cool or warm preferences), and environmental parameters can improve the prediction accuracy of the model.

PMV is a method to predict thermal sensation specified in ISO 7730, which can satisfy the thermal comfort requirements for general populations, but is limited in predicting individual thermal sensations. In recent years, the increasing demands from a group-level to an individual-level have promoted the development of personal thermal comfort.

ISO 9886 is suitable for evaluating human thermal strain, these physiological parameters such as body core temperature, skin temperature, heart rate and body-mass loss, whereas its applicability to thermal evaluation in moderate environments is limited.

ISO 14505-3 provides an example where mean skin temperature may be used as an objective parameter correlated with thermal comfort. However, the standard does not specify corresponding detailed methodologies.