Effect of applying phase change materials (PCM) in building facades on reducing energy consumption

Since fossil fuels are limited and there is an increasing demand for energy consumption, energy conservation and reducing consumption have become significant challenges. Applying phase change materials (PCM) for latent thermal energy storage (TES) systems is an effective method for energy conservation that has been widely considered in recent years. The building facade has the highest capacity for conserving or wasting energy due to its vast exposure to the environment. As a result, a change in attitude toward designing and constructing facades is considered a necessity since it is one of the key elements of building design. One approach to prevent materials from leaching from a structure where PCMs are incorporated is encapsulating and blending them with a suitable polymer. Choosing a PCM with suitable melting temperature, a polymer compatible with this material as a preserver and the best percentage of PCM in the polymer are key components. In this paper, the goal has been investigated through a 2-step process, including experimental and simulation phases. First, the effect of polyethylene glycol (PEG) as the PCM in the mixture with poly methyl methacrylate (PMMA) for heat protection has been studied. Differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) measurement techniques were employed to study and determine the melting points of the samples and the mixed substructures. The results show that the best percentage for PEG in this research is 60%. In the second phase, to study the effect of polymers carrying the PCMs on the building’s energy consumption, a 5-story building with PCMs applied to its facade was simulated in EnergyPlus software. The annual heating and cooling loads of the building in each situation were then calculated. The results of the simulation and modeling shows that applying the PCMs will ultimately lead to a 40% decrease in heating load and 15% decrease in cooling load of the building. • Phase change materials in building facades are effective for energy conservation. • Specific compositions of phase change materials can lead to more efficient results. • Phase change materials contribute in reducing heat loads more than cooling loads.