Thermal sensation and skin temperature during step-changes in non-uniform indoor environment

To examine thermal sensation in non-uniform environment, this paper studied overall thermal sensation and skin temperature during step-change between an ambient and the workstation where local ventilation device was installed to supply air motion around the head. 23 human subject tests were conducted in summer for cooling in a controlled environment chamber. Thermal sensations and skin temperatures were collected and analysed by statistical tests. Thermal sensation's changing trends of hysteresis and overshooting were found respectively after stepping into the ambient and the workstation. Face skin temperature changed closely with thermal sensation, while it had no overshooting phenomenon as thermal sensation did. The minimum change of face skin temperature required for a just noticeable difference on thermal sensation was calculated. In conclusion, thermal sensation's changing rules are comfort positive for non-uniform thermal environment. Face skin temperature well explained thermal sensation's changing characters during step-changes with different local cooling methods.