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Green roof systems have become an important part in creating sustainable cities. They can provide a wide range of economic, environmental, and social benefits. The goal of this research was to quantify the thermal performance improvements from a green roof with mineral wool substrate installed on a school building in a humid subtropical climate. In-situ measurements during a summer period included heat fluxes through the green and reference roof, vertical temperature profile through both roofs, the local air temperature above roofs, and local meteorological parameters. Furthermore, the summer thermal performance of green and reference roof and the green roof cooling effect were evaluated concerning meteorological parameters using the Pearson correlation analysis. The results indicate that the green roof layers have improved thermal performance of the roof with respect to reduced conductive heat flow by 57% and delayed heat transfer. The maximum and averaged reference roof to green roof outdoor surface temperature difference was 27.5 °C and 5.5 °C, respectively. It was found that ambient temperature and relative humidity have a dominant role on the thermal performance of the green and reference roof, while solar radiation and ambient temperature present the key meteorological determinants of the green roof cooling effect.

The paper deals with a comprehensive, three-dimensional numerical CFD analysis of temperature fields in Trombe wall and in the adjacent room for several days of a typical meteorological year (TMY) for a moderate continental climate. Construction of the Trombe wall is optimized, using different types of glassing on the outside of the wall. For summer day, the glass is considered to be covered with PV stripes during the daylight in order to prevent overheating. The central concrete core of the wall is covered with a layer of dark paint, on the outside, to improve absorptivity of the wall. The Trombe wall is oriented on south side of the house, and designed with openings with flaps in concrete core. Those openings are simulated in opened and closed positions. The U-values of the house envelope are considered according to passive house standards. Temperature fields in concrete core and in the room with Trombe wall are simulated, as well as velocity fields. According to these results, analysis of energy savings potential is performed.