The first aim of our research is to calculate the solar irradiance on roofs assuming clear sky and real (climatologically typical) conditions, respectively, and compare them in a densely built inner city study area in Szeged (Hungary). The second aim is to analyse the shading effect of the tree-crowns on the possible solar energy gain of building roofs. The calculation of the climatologically potential solar energy gain based on an empirical atmospheric transmittance (calculated from the measured global radiation values). The results show that in the case of clear sky condition the urban vegetation (tree-crowns) causes significant potential solar energy loss on the roofs, but in the real situations this effect is less significant. These obtained results clearly illustrate how useful tool could be the presented calculation method at the economical and technical planning stage of the installation of solar systems on roofs.
This paper presents a thermal comfort study of a popular playground in Szeged, Hungary in order to find its optimal land cover and vegetation options. For this assessment simulated micro- and bioclimatological conditions recorded on a typical summer day (12th July 2011) were analysed. The thermal and radiation features of the study area were quantified by two biometeorological indices, Predicted Mean Vote (PMV) and Mean Radiant Temperature (Tmrt). For the simulation of the meteorological parameters and the bioclimate indices, ENVI-met microclimate model was used. The results confirmed that the modelled areas with different land cover provide a variety of thermal conditions for the visitors; moreover, human thermal sensation was significantly affected by the change of the radiation environment.