Mean Radiant Temperature Sensing: Comparison of Methods for a Non-Uniform Radiant Floor Heating

Abstract

Non-uniform radiant floor heating is increasingly explored for improving localized and personalized thermal comfort. Accurate mean radiant temperature (T<inf>r</inf>) measurement is crucial due to its separation from air temperature (T<inf>a</inf>) unlike convective systems. This study evaluates the accuracy of T<inf>r</inf> obtained using the globe thermometer versus a novel mini.RES cube sensor and examines the differences between T<inf>a</inf> and T<inf>r</inf> in non-uniform heating environments. Experiments were conducted in a 62 m3 climatic chamber in Fribourg, Switzerland, with four cases: one without heating, two with non-uniform heating to simulate radiant asymmetry, and one with uniform heating for comparison. Additionally, an uncertainty analysis was performed to evaluate measurement precision for the T<inf>r</inf> measurements using the globe thermometer. The results indicate that the globe thermometer method can introduce errors of up to 4% in determining the T<inf>r</inf>. Moreover, the uncertainty values for the T<inf>r</inf> values were found between 1.60 ℃ and 2.31 ℃. In cases with non-uniform heating available, the T<inf>r</inf> was found to vary by more than 2 ℃ than the T<inf>a</inf>, highlighting the need to consider T<inf>r</inf> separately when assessing thermal comfort. These findings emphasize the error of obtaining the T<inf>r</inf> with globe thermometer and the difference between T<inf>r</inf> and T<inf>a</inf> in non-uniform heating scenarios. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2026.