In the analysis of the human heat balance, the biggest problem is to precisely determine the amount of energy absorbed by a human organism under dynamically changing solar conditions and while being surrounded by many different surfaces that can absorb, emit or reflect solar radiation in different ways. Therefore, in thermal comfort studies some simplifications of the radiation field around human body are necessary and thus the concept of mean radiant temperature (Mrt) is most often used. Mrt values can be derived either from direct instrumental measurements or calculated by one of the microclimate models. The most accurate way to determine the Tmrt outdoors is by integral radiation measurements and the calculation of angular factors (i.e. the proportion of radiation received by the human body from different directions). This method involves simultaneous measurements of long- and short-wave radiation flux densities in six directions, which requires three sets of net radiometers. Although this method of Mrt determination describes the radiation environment accurately and independently of the variable wind field, it requires the use of expensive and complex measurement devices. Cheap and easy to operate alternative offers globe thermometer. In steady state conditions, readings from the air temperature sensor inside the globe thermometer (tg) will reflect the convective and radiative heat exchange around the globe thermometer. Knowing tg, as well as globe emissivity and diameter, the Mrt may be calculated. In this research three different globe thermometers were used to determine Mrt: 15-cm standard globe thermometer (SGT) and two 4-cm custom made acrylic globe thermometers (AGT) painted in black and grey. The measurements were conducted in the summer in Warsaw, on two selected green areas, under sunny and warm weather conditions. In each location Mrt measurements were taken in two spots – in the shade of trees and in the open grassy spaces, with high SVF. Our results demonstrate, that globe thermometers, although being relatively cheap and less complex instruments for determining Mrt, can be used to a limited extend, due to high instability of their indications under significant radiative loads.
American National Standards Institute. (2004). Thermal environmental conditions for human occupancy ASHRAE Standard-55.
Banfi, A., Tatti, A., Ferrando, M., Fustinoni, D., Zanghirella, F., & Causone, F. (2022). An experimental technique based on globe thermometers for the measurement of mean radiant temperature in urban settings. Building and Environment, 222, 109373. https://doi.org/10.1016/j.buildenv.2022.109373
Bergman, T.L., DeWitt, D.P., Incropera, F.P., & Lavine, A.S. (2006). Fundamentals of Heat and Mass Transfer (6th ed.). Hoboken: John Wiley & Sons, Ltd.
Błażejczyk, K. (2005). MENEX_2005 − the updated version of man- environment heat exchangemodel. Pobrane z: https://www.igipz.pan.pl/BioKlima.html
Błażejczyk, K., Jendritzky, G., Bröde, P., Fiala, D., Havenith, G., Epstein, Y., Psikuta, A., & Kampmann, B. (2013). An introduction to the Universal thermal climate index (UTCI). Geographia Polonica, 86(1), 5‑10. https://doi.org/10.7163/GPol.2013.1
Błażejczyk, K., & Kunert, A. (2011). Bioklimatyczne uwarunkowania rekreacji i turystyki w Polsce = Bioclimatic principles of recreation and tourism in Poland (2nd ed.). Warszawa: IGiPZ PAN. Pobrane z: http://rcin.org.pl/igipz/Content/19801/WA51_39725_r2011-nr13_Monografie.pdf
Budd, G.M. (2008). Wet-bulb globe temperature (WBGT) - its history and its limitations. Journal of Science and Medicine in Sport, 11(1), 20‑32. https://doi.org/https://doi.org/10.1016/j.jsams.2007.07.003
Chen, Y.C., Lin, T.P., & Matzarakis, A. (2014). Comparison of mean radiant temperature from field experiment and modelling: a case study in Freiburg, Germany. Theoretical and Applied Climatology, 118(3), 535‑551. https://doi.org/10.1007/s00704-013-1081-z
d'Ambrosio Alfano, F.R., Dell'isola, M., Ficco, G., Palella, B.I., & Riccio, G. (2021). On the measurement of the mean radiant temperature by means of globes: An experimental investigation under black enclosure conditions. Building and Environment, 193, 107655. https://doi.org/10.1016/j.buildenv.2021.107655
d'Ambrosio Alfano, F.R., Dell'Isola, M., Palella, B.I., Riccio, G., & Russi, A. (2013). On the measurement of the mean radiant temperature and its influence on the indoor thermal environment assessment. Building and Environment, 63, 79‑88. https://doi.org/10.1016/j.buildenv.2013.01.026
Du, J., Sun, C., Liu, L., Chen, X., & Liu, J. (2021). Comparison and modification of measurement and simulation techniques for estimating Tmrt in summer and winter in a severely cold region. Building and Environment, 199, 107918. https://doi.org/10.1016/j.buildenv.2021.107918
Fanger, P.O. (1970). Thermal Comfort. Analysis and Applications in Environmental Engineering. Copenhagen: Danish Technical Press.
Gál, C.V., & Kántor, N. (2020). Modeling mean radiant temperature in outdoor spaces, A comparative numerical simulation and validation study. Urban Climate, 32, 100571. https://doi.org/10.1016/j.uclim.2019.100571
Guo, H., Aviv, D., Loyola, M., Teitelbaum, E., Houchois, N., & Meggers, F. (2020). On the understanding of the mean radiant temperature within both the indoor and outdoor environment, a critical review. Renewable and Sustainable Energy Reviews, 117, 109207. https://doi.org/10.1016/j.rser.2019.06.014
Hey, E.N. (1968). Small globe thermometers. Journal of Physics E: Scientific Instruments, 1(9), 955. https://doi.org/10.1088/0022-3735/1/9/424
Höppe, P. (1992). A new procedure to determine the mean radiant temperature outdoors. Wetter Und Leben, 44(1‑3), 147‑151.
Humphreys, M.A. (1977). The optimum diameter for a globe thermometer for use indoors. The Annals of Occupational Hygiene, 20(2), 135‑140. https://doi.org/10.1093/annhyg/20.2.135
International Organization for Standardization. (1998). ISO 7726: Ergonomics of the Thermal Environment - Instruments for Measuring Physical Quantities. Genève: ISO.
Johansson, E., Thorsson, S., Emmanuel, R., & Krüger, E. (2014). Instruments and methods in outdoor thermal comfort studies - The need for standardization. Urban Climate, 10, 346‑366. https://doi.org/10.1016/j.uclim.2013.12.002
Kántor, N., Kovács, A., & Lin, T.P. (2015). Looking for simple correction functions between the mean radiant temperature from the "standard black globe" and the "six-directional" techniques in Taiwan. Theoretical and Applied Climatology, 121(1‑2), 99‑111. https://doi.org/10.1007/s00704-014-1211-2
Kántor, N., & Unger, J. (2011). The most problematic variable in the course of human-biometeorological comfort assessment - the mean radiant temperature. Central European Journal of Geosciences, 3(1), 90‑100. https://doi.org/10.2478/s13533-011-0010-x
Kenny, N.A., Warland, J.S., Brown, R.D., & Gillespie, T.G. (2008). Estimating the radiation absorbed by a human. International Journal of Biometeorology, 52(6), 491‑503. https://doi.org/10.1007/s00484-008-0145-8
Kuehn, L.A., Stubbs, R.A., & Weaver, R.S. (1970). Theory of the globe thermometer. Journal of Applied Physiology, 29(5), 750‑757. https://doi.org/10.1152/jappl.19220.127.116.110
Liu, K., You, W., Chen, X., & Liu, W. (2022). Study on the Influence of Globe Thermometer Method on the Accuracy of Calculating Outdoor Mean Radiant Temperature and Thermal Comfort. Atmosphere, 13(5), 809. https://doi.org/10.3390/atmos13050809
Mayer, H., & Höppe, P. (1987). Thermal comfort of man in different urban environments. Theoretical and Applied Climatology, 38(1), 43‑49. https://doi.org/10.1007/BF00866252
Nikolopoulou, M., Baker, N., & Steemers, K. (1999). Improvements to the Globe Thermometer for Outdoor Use. Architectural Science Review, 42(1), 27‑34. https://doi.org/10.1080/00038628.1999.9696845
Oliveira, A.V.M., Raimundo, A.M., Gaspar, A.R., & Quintela, D.A. (2019). Globe Temperature and Its Measurement: Requirements and Limitations. Annals of Work Exposures and Health, 63(7), 743‑758. https://doi.org/10.1093/annweh/wxz042
Staiger, H., & Matzarakis, A. (2020). Accuracy of mean radiant temperature derived from active and passive radiometry. Atmosphere, 11(8), 1‑22. https://doi.org/10.3390/ATMOS11080805
Tan, C.L., Wong, N.H., & Jusuf, S.K. (2013). Outdoor mean radiant temperature estimation in the tropical urban environment. Building and Environment, 64, 118‑129. https://doi.org/10.1016/j.buildenv.2013.03.012
Tang, P., & Li, Q. (2022). Evaluation of the observation methods of outdoor mean radiant temperature in a subtropical city. Building and Environment, 207(PB), 108462. https://doi.org/10.1016/j.buildenv.2021.108462
Teitelbaum, E., Alsaad, H., Aviv, D., Kim, A., Voelker, C., Meggers, F., & Pantelic, J. (2022). Addressing a systematic error correcting for free and mixed convection when measuring mean radiant temperature with globe thermometers. Scientific Reports, 12(1), 1‑18. https://doi.org/10.1038/s41598-022-10172-5
Teitelbaum, E., Chen, K.W., Meggers, F., Guo, H., Houchois, N., Pantelic, J., & Rysanek, A. (2020). Globe thermometer free convection error potentials. Scientific Reports, 10(1), 1‑13. https://doi.org/10.1038/s41598-020-59441-1
Thorsson, S., Lindberg, F., Eliasson, I., & Holmer, B. (2007). Different methods for estimating the mean radiant temperature in an outdoor urban setting. International Journal of Climatology, 27, 1983‑1993. https://doi.org/10.1002/joc.1537
Vanos, J.K., Rykaczewski, K., Middel, A., Vecellio, D.J., Brown, R.D., & Gillespie, T.J. (2021). Improved methods for estimating mean radiant temperature in hot and sunny outdoor settings. International Journal of Biometeorology, 65(6), 967‑983. https://doi.org/10.1007/s00484-021-02131-y
Verein Deutscher Ingenieure. (2008). VDI 3787 - Part 2: Environmental meteorology Methods for the human biometeorological evaluation of climate and air quality for urban and regional planning at regional level Part I: Climate. Berlin: Beuth.
Vernon, H. (1932). The measurement of radiant heat in relation to human comfort. Journal of Idustrial Hygiene, 14, 95‑111.
Wang, S., & Li, Y. (2015). Suitability of acrylic and copper globe thermometers for diurnal outdoor settings. Building and Environment, 89, 279‑294. https://doi.org/10.1016/j.buildenv.2015.03.002
Weihs, P., Staiger, H., Tinz, B., Batchvarova, E., Rieder, H., Vuilleumier, L., Maturilli, M., & Jendritzky, G. (2012). The uncertainty of UTCI due to uncertainties in the determination of radiation fluxes derived from measured and observed meteorological data. International Journal of Biometeorology, 56(3), 537‑555. https://doi.org/10.1007/s00484-011-0416-7