Passive solar design strategies for buildings are necessary for annual heating energy demand reduction. This paper presents a mathematical model for interior room temperature calculation of a building that integrates a combined passive solar system consisting of an unvented Trombe wall and a direct passive solar system for direct insolation. The model was applied to a residential building located in Niš, Serbia, which is not additionally heated by conventional fuels. Two variations of a combined passive system were taken into consideration. The first combined passive system consisted of a Trombe wall made of 0.45-m-thick concrete and the second combined passive system consisted of a 0.20-m-thick concrete Trombe wall. To calculate the complex mathematical model, depending on the size of the window opening, window slope (slanting or vertical position), and orientation of the room, two software packages were developed, RMSun and InSunTr. In addition, the indoor air temperatures of a thermally insulated residential building with an unvented Trombe wall and a direct passive solar system for different building orientations and different Trombe wall thicknesses were analyzed during the winter period between January and March.

Despite the multiple contributions of public open spaces (POSs) to the quality of life in large housing estates (LHEs), the comprehensive treatment of their improvement has so far been a rare occasion in post-socialist countries. This paper aimed to explore the transformations of POSs in inherited LHEs in the socialist and post-socialist period and the potential for their regeneration. The investigation was based on a comparative analysis of two case studies in Niš, Serbia, which represent typical modes of POS devastation. The performed research study has shown that POSs have succumbed to dilapidation, displaying a wide array of problems and that their regeneration is neglected. The paper proposes a comprehensive set of measures to regenerate POSs based on contemporary concepts of urban planning and design with a special focus on long-term actions and residents’ needs. Particular importance is given to establishing the development guidelines as future prerequisites for overcoming current institutional, economic, legislative, and social obstacles for sustainable implementation of regeneration measures. These findings might encourage future studies of creating a model option for improving POSs at the city of Nis scale, as well in other Serbian cities towards sustainable urban development.

Outdoor thermal environment is affected by variables like air temperature, wind velocity, humidity, temperature of the radiant surfaces, and solar radiation, which can be expressed by a single number - the thermal index. Since these variables are subject to annual and diurnal variations, prediction of thermal comfort is of special importance for people to plan their outdoor activities. The purpose of this research was to develop and apply the extreme learning machine for forecasting physiological equivalent temperature values. The results of the extreme learning machine model were compared with genetic programming and artificial neural network. The reliability of the computational models was accessed based on simulation results and using several statistical indicators. According to obtained results, it can be concluded that extreme learning machine can be utilized effectively in short term forecasting of physiological equivalent temperature.

Energy consumption has reached its highest level globally. Buildings have the largest share in total energy consumption, so designers must take into account their functioning and the consequences that can arise. Passive solar design is an imperative in modern architecture, and Trombe wall, as one of the principles of this design, is certainly distinguished. The paper presents an overview of the characteristics of the construction of the Trombe Wall in order to improve thermal stability and reduce energy consumption in buildings. Starting from the consideration of climatic influencing factors, through the heat capacity of the materials applied and their thickness and color of the thermal mass, it is very important to know in detail all the factors that can lead to the improvement of the efficiency of this system. The specific heat of the walls in the building, the time delay, the decrement factor and the influence and position of the thermal insulation were also taken into account. The effect of glazing as well as the influence of the ventilation openings were highlighted as significant elements. On the basis of the analysis of the above components, the conclusions and guidelines for designing this type of constructions were made in order to improve the efficiency and reduced energy consumption while providing adequate comfort in the facility.

The process of urban shrinkage is affecting many cities around the world. It is evident in small towns as well, but unlike larger cities, it has not received much attention. Accordingly, this paper analyses small towns? shrinking focusing on post-socialist context of development, which led to new patterns of urban shrinkage in countries of Central and Eastern Europe (CEE). After discussing the specific characteristics of the shrinkage of small towns, their paths of development in different CEE countries are analyzed, in order to highlight the characteristics of urban shrinkage and the influence of post-socialist transition on this process. Thereafter, the shrinkage of small towns in Serbia is analyzed in order to determine whether the identified characteristics are recognized in them and to single out the specifics of that process in relation to other post-socialist countries. Based on the general characteristics of the development and shrinkage of small towns in the CEE countries, it can be concluded that shrinking small towns are not equally represented in all countries, and there are certain differences in terms of dynamics and intensity of shrinkage. The results of the analysis indicate that the previous path of development had a strong influence on their shrinkage after the post-socialist transformation. Three general trajectories of socialist development have been singled out, which influenced different patterns of urban shrinkage. In Serbia, it has also been observed that the shrinkage of small towns is directly related to the unfavourable direction of the urbanization process during socialist development.

The analysis conducted in this paper was initiated by the fact that Serbia emitted around 80 million tons of CO2, equivalent in 1990, and in between 85-89 million tons in 2010, which places it among ten countries with the highest emission of CO2 per capita in the world (data by Cener for Ecology and Sustainable Development, Subotica, Serbia). This paper is aimed at making a correlation between the improvement of thermal performance of structural elements of buildings in order to enhance their energy efficiency, which is also economically justified, and reduction of GHG (CO2) emission whose economic benefits are not so easy to assess even though it represents an environmental problem. The case study analysis, presented by this paper, using the example of a select number of kindergartens in the territory of the city of Nis, Serbia, is aimed at determining the correlation of the effects of improvement of their energy performances on the reduction of GHG emission reduction by quantifying the benefits of CO2 emission reduction as a result of energy efficiency improvement reflected through the increase of energy class. The specific review conducted in this paper indicates the environmental importance of improvement of energy efficiency by valorizing the quantitative reduction of CO2 emission as a benefit of implementation of energy revitalization of buildings.