Optimizing PCM Integrated Wall and Roof for Energy Saving in Building under Various Climatic Conditions of Mediterranean Region

Abstract

Energy conservation in buildings has been the focus of many studies since nearly one-third of global energy consumption is due to buildings. Phase change material (PCM) technology promises to be an attractive solution for energy saving in buildings since it is a passive and effective technology, as demonstrated in the literature. Therefore, this study focuses on the energy-saving performance of PCM-integrated buildings located in a Mediterranean climate to reveal their energy-saving potential. PCM is integrated both in external or internal south walls and roofs of buildings under four different climatic conditions. EnergyPlus, which is a well-known building simulation software, is adopted for building thermal analyses. The effects of melting temperature, location of PCM layer in the wall, thickness of PCM layer, type of envelope (wall or roof), and PCM double-layer system in the wall are investigated. The corresponding energy savings and CO2 emission reductions are obtained for the considered cases. The results showed that up to 41.6% reduction in energy demand can be obtained depending on the PCM application. Besides, PCM with a low melting temperature (21 °C) favored heating energy savings, while PCM with a high melting temperature (29 °C) favored cooling energy savings. Moreover, the double-layer PCM system provided higher energy savings than the single-layer PCM system, especially in warm and arid regions (Sousse and Tozeur).

A Systematic Analysis of Phase Change Material and Optically Advanced Roof Coatings Integration for Athenian Climatic Conditions

“…For the heating design, the most efficient PCM is RT22, characterized by a lower mean transition temperature of 22 • C. On the other hand, for the cooling design, the most effective PCM is RT28, defined by a higher mean transition temperature of 28 • C. The highest possible seasonal thermal load energy savings are achieved with a PCM defined by a mean transition temperature similar to the building's seasonal indoor temperature setpoint. This conclusion is validated by the study of Dardouri et al [18], who focused their study on various locations of Mediterranean climatic conditions in Tunisia and calculated that a PCM with a lower melting temperature of 21 • C is more effective for maximizing heating energy savings, while a PCM with a higher melting temperature of 29 • C allows higher cooling energy savings. Additionally, the increase in the PCM's thickness allows the reduction of the cumulative electricity demand for heating and cooling, with the reduction ranging from 5.65% to 13.55%.…”

“…Moreover, Jayalath et al [17] concluded that a PCM roof layer with a mean transition temperature of 23 • C can lead to a 39% reduction in energy consumption for cooling and a 12% reduction in energy consumption for heating for a one-story residential building in Melbourne. Regarding various areas with a Mediterranean climate, Dardouri et al [18] calculated that the modulation of the PCM layer on the roof has an immediate effect on the building's thermal loads, leading to a cumulative energy reduction in the range of 8% to 31.5%.…”

Thermal behavior of a PCM-plywood combination as insulation for buildings in a hot summer condition

“…It was reported that the use of the PCM elements with doubled-layer provided lower energy consumption than the single-layer one, specifically in warm-arid regions [2]. This highlights the importance of the number of PCM layers, location, and thickness.…”

“…The simulation results showed that adopting PCM layouts in conjunction with ventilation can increase the thermal performance of the thermal comfort conditions during the hotter seasons. Using PCM with a melting temperature of 21℃ has preferred heating energy savings, while PCM with 29℃ melting temperature has better cooling energy savings as reported by Dardouri et al [2]. An advanced nanoparticle improved PCM (nano-PCM) was developed by Biswas et al [24].…”

“…Therefore, using PCM (Phase Change Materials) outfitted with the building's walls is a promising technique. The results from Dardouri et al [2] showed that up to a 41.6% drop in the required energy for cooling or heating can be found based on the application of PCM. Several studies have dealt with this topic regarding its performance based on effective position, encapsulation area melting point, and thickness.…”