Evaluation of Thermal Performance with the Development of a Prototype Made up of Series Concrete Walls and EPS Sheets with the Application of Fourier's Law

Recent civil engineering research has focused on developing environmentally friendly materials and promoting sustainable energy use. In building construction, elements such as walls, windows, roofs, and floors form the building envelope, mediating internal conditions from external climate. Understanding thermal transmittance and environmental interactions enables evaluation of a building’s response to temperature, solar radiation, and wind, guiding technical solutions for adequate thermal performance. EPS (expanded polystyrene) is widely recognized for its high thermal insulation due to its closed cellular structure, reducing heat transfer and energy consumption for heating and cooling. This study developed a concrete-brick prototype lined with EPS plates of 2 cm and 3 cm thickness to evaluate their impact on indoor comfort. Internal temperatures were measured 0.5, 1, and 2 hours after exposure to a 60 W heat source, with and without EPS. After 2 hours, the 2 cm EPS wall reached 26 °C, while the uninsulated wall reached 41 °C. Increasing EPS thickness significantly improves insulation, although the 28% additional heat flux reduction must be weighed against cost and feasibility.