Lilla Andrea Égerházi

Subjective estimation of thermal environment in recreational urban spaces-Part 1: Investigations in Szeged, Hungary

During two investigation periods in transient seasons (14 weekdays in autumn 2009 and 15 weekdays in spring 2010) 967 visitors in two inner city squares of Szeged (Hungary) were asked about their estimation of their thermal environment. Interrelationships of subjective assessments—thermal sensation, perceptions and preferences for individual climate parameters—were analyzed, as well as their connections with the prevailing thermal conditions [air temperature, relative humidity, wind velocity, mean radiant temperature and physiologically equivalent temperature (PET)]. Thermal sensation showed strong positive relationships with air temperature and solar radiation perception, while wind velocity and air humidity perception had a negative (and weaker) impact. If a parameter was perceived to be low or weak, then it was usually desired to be higher or stronger. This negative correlation was weakest in the case of humidity. Of the basic meteorological parameters, Hungarians are most sensitive to variations in wind. Above PET = 29°C, people usually prefer lower air temperature and less solar radiation. The temperature values perceived by the interviewees correlated stronger with PET, but their means were more similar to air temperature. It was also found that the mean thermal sensation of Hungarians in transient seasons depends on PET according to a quadratic function (R2 = 0.912) and, consequently, the thermal comfort ranges of the locals differ from that usually adopted.

Evaluation and modelling the micro-bioclimatological conditions of a popular playground in Szeged, Hungary

Abstract 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.

Application of Microclimate Modelling and Onsite Survey in Planning Practice Related to an Urban Micro-Environment

Numerical simulations of human thermal comfort conditions were carried out by means of the urban microclimate model ENVI-met in a popular children’s playground located in Szeged, Hungary. Bioclimatic conditions were quantified by the Physiologically Equivalent Temperature (PET). Based on the PET values, thermal stress maps were created in two different periods of typical summer and autumn days. The study aims to reveal the seasonal and diurnal spatial patterns of the simulated thermal conditions and thus the degree of heat stress in different parts of the playground. Furthermore, we analysed the momentary spatial distributions of the visitors triggered by the microclimatic conditions of the area. According to the simulation, remarkable differences in the thermal conditions were found depending on the sun elevation and the resulting shaded conditions as well as the radiation of the heated surfaces. The spatial distribution of the visitors seems to be highly influenced by the patterns of the thermal conditions but the location and the preference of the children’s playground equipment also affects it. In order to reveal the possible causes of the people’s behaviour, an onsite questionnaire survey was conducted on their opinions and possible modification requirements related to the design of the playground.