Etude exergetique d’une ambiance chaude en climat tropical

Abstract

Energy efficiency represents a major global challenge, making the search for sustainable solutions a priority to address the electricity access deficit while minimizing energy losses in existing infrastructures. In this context, our study focuses on the exergy analysis of a building in a tropical environment, specifically located in the Melen neighborhood of Yaoundé. The objective is to evaluate the building's energy efficiency by examining exergy flows to optimize energy use.We developed a physical model divided into several subsystems: the "air conditioning" subsystem, the "ground" subsystem, the "flat wall" subsystem, and the "window" subsystem. The mathematical model derived from this approach is based on thermal transfer through each component, thus determining the daily exergy destruction. This methodology allowed us to evaluate the exergy destruction of each subsystem during the hottest months (February) and the coldest months (August) of the year 2020. An exergy study was conducted to determine the reference temperature, comparing three choices: the comfort temperature (24°C), the monthly maximum temperature, and the daily average temperature. The results indicate that the daily average temperature is the optimal choice for analysis in a tropical environment. The exergy analysis of the building revealed that the air conditioning system is responsible for significant exergy losses. Additionally, it was demonstrated that the concrete used for walls and the ground leads to greater energy losses than the double-glazed glass used for windows and doors. This underscores the need to use materials such as phase change materials or advanced insulations to improve the exergy efficiency of building envelopes. Finally, a seasonal evaluation shows that the building destroys more energy when temperatures are low (August 2020). These results highlight the importance of material and equipment selection in building design to enhance energy efficiency.