Future performance evaluation of PCM integrated buildings under changing climate

Abstract

The high energy consumption and associated carbon emissions due to the heating and cooling of buildings create a heavy environmental burden. One of the cost-efficient solutions to reduce the heating and cooling demands is to incorporate phase change materials (PCMs) in the building components, increasing the thermal mass of the building and providing latent heat thermal storage. However, the rising temperatures over the years will alter the effectiveness of PCM in building envelopes. In this study, four cities in Turkey with different climatic characteristics were selected. For each city, future weather files representing the climatic conditions of 2050 and 2080 were generated from the current weather data using CCWorldWeatherGen. A typical office building that utilizes gypsum wallboards was modeled with EnergyPlus as a reference case. Alternative energy models were generated by modifying the wallboard compositions (PCM melting temperature: 19-27°C). The building's annual heating and cooling energy demands were calculated for each city, year, and wallboard alternative. Generated data were analyzed to evaluate the future efficiency of the wallboards with the changing climate over the years in order to maximize the long-term performance gains from PCM incorporating wallboards. The results showed that the selection of the optimum PCM melting temperature of a location should not only depend on thermo-physical and layer properties of the PCM wallboard as the optimum melting temperature of the PCM is subject to change with rising temperatures. The impact of climate change should be considered to fully evaluate the long-term performance of the PCM wallboard in terms of energy use and CO2 emissions.