International Journal of Biometeorology

, Volume 51, Issue 4, pp 323–334 | Cite as

Modelling radiation fluxes in simple and complex environments—application of the RayMan model

  • Andreas MatzarakisEmail author
  • Frank Rutz
  • Helmut Mayer
Original Article


The most important meteorological parameter affecting the human energy balance during sunny weather conditions is the mean radiant temperature Tmrt. It considers the uniform temperature of a surrounding surface giving off blackbody radiation, which results in the same energy gain of a human body given the prevailing radiation fluxes. This energy gain usually varies considerably in open space conditions. In this paper, the model ‘RayMan’, used for the calculation of short- and long-wave radiation fluxes on the human body, is presented. The model, which takes complex urban structures into account, is suitable for several applications in urban areas such as urban planning and street design. The final output of the model is, however, the calculated Tmrt, which is required in the human energy balance model, and thus also for the assessment of the urban bioclimate, with the use of thermal indices such as predicted mean vote (PMV), physiologically equivalent temperature (PET) and standard effective temperature (SET*). The model has been developed based on the German VDI-Guidelines 3789, Part II (environmental meteorology, interactions between atmosphere and surfaces; calculation of short- and long-wave radiation) and VDI-3787 (environmental meteorology, methods for the human-biometeorological evaluation of climate and air quality for urban and regional planning. Part I: climate). The validation of the results of the RayMan model agrees with similar results obtained from experimental studies.


RayMan Mean radiant temperature Urban climate Urban planning Physiologically equivalent temperature PET 



Thanks to Nikola Sander for proofreading and editing the manuscript. Cordial thanks to the RayMan users for their suggestions and validations for the further development of the model.


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Copyright information

© ISB 2006

Authors and Affiliations

  1. 1.Meteorological InstituteUniversity of FreiburgFreiburgGermany

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