REASSESSING PASSIVE SOLAR HEATING SYSTEMS IN THE SMALL-VOLUME RESIDENTIAL BUILDING: ENERGY AND THERMAL CHALLENGES IN GREECE, SERBIA AND POLAND UNDER A CHANGING CLIMATE

Abstract

Passive solar heating systems present techniques and strategies designed to reduce energy demand for space heating in buildings located in Mediterranean, moderate continental and continental climate zones. However, progressing climate change increasingly challenges their effectiveness, especially in small-volume residential buildings, as milder winters and rising external temperatures can easily lead to overheating during the heating season and additional demand for space cooling. This paper investigates the energy performance and thermal comfort in the small-volume residential building, depending on climate location (Athens, Kragujevac, and Kielce) and the types of passive solar measures (passive Trombe wall, selective coating, insulation thickness and window dimensions). The building was modeled in Google SketchUp and simulated in EnergyPlus software using real weather data for a seven-month heating season (from 1 October to 30 April). Compared to the basic building model (without passive solar system), numerical results demonstrate that, while passive solar heating systems reduce heating energy consumption, they can cause significant space overheating, especially during shoulder months. Consequently, the additional cooling demand partially offsets the heating savings. In all simulation scenarios, the Polish climate exhibited less overheating but lower total final energy savings for space heating and cooling (3.52–11.03 %), compared to Serbian (6.79–14.06 %) and Greek (8.12–13.77 %) climates. The findings also suggest that, under ongoing climate trends, passive solar systems may gradually lose their privileged status as a sustainable heating strategy unless technologically adapted to changing thermal conditions.