Comparison of thermal comfort and sensation scales : a case study

Thermal sensation is a conscious feeling that grades the thermal environment, while thermal comfort expresses satisfaction with this feeling. Multiple scales to quantify thermal sensation and comfort have been developed throughout the history of research on thermal comfort. In this paper, the most important scales for measuring thermal sensation are compared and evaluated. Of all scales, the ASHRAE 7-point scale (from cold, through neutral, to hot) is the most common. To measure comfort these scales are often presented together with an acceptability or a comfort scale. Another widely used scale, the Bedford scale uses also 7 points, but combines thermal comfort and sensation by coding from much too cool to much too warm with comfortable in the middle. The preference scale is to use to express whether the respondent would prefer warmer or cooler thermal environment. To compare difference between different thermal comfort scales a case study was conducted, in which a number of respondents were asked to report their thermal comfort. Different scales were presented to the respondents under same thermal environmental parameters. The responses on different scales have been compared. The findings of this study can give a guidance to compare thermal comfort studies using different scales