Reinterpretation of a thermal environment evaluation index "standard effective temperature (SET)"

The standard effective temperature (SET) is an evaluation index based on the two-node thermal physiological model which has been widely used to evaluate thermal comfort. However, the SET is often misused due to misunderstanding the SET equivalent standard environment and differences in some key parameters. This study summarizes the development of the SET index and then reinterprets this index based on Gagge's definition in the 1986 version to correct the misunderstanding of the standard SET environment. In addition, the equivalent standard environment parameters vary with the metabolic rate. The SET calculational method is revised here to correct these problems with guidelines for future applications of the SET index.