Energy exchange of Inserting Eco-friendly Bio Phase Change Material into the vertical walls to make the buildings energy-efficient

In this study, the thermal behavior of a building in the presence of PCM and BioPCM were discussed. Two-phase method was used for BioPCM modeling and the energy exchange was determined by accounting solar radiation on vertical surfaces (walls) and roof. Unlike other PCMs, which are based on petroleum or salt derivatives, BioPCMs are made from natural and plant materials and are therefore environmentally friendly. For a building without BioPCM, the annual energy consumption is 23.64 kWhm2, and if BioPCM M182/Q21 which is always solid, is used, the annual energy is reduced by 13%. If PCM with the chance of phase change is used, the annual energy utilization dropped by 28% which reveals that the possibility of the phase change is very effective in reducing energy consumption. In addition to BioPCM M182/Q21, several BioPCMs with different enthalpy-temperature curves were used and it was found that BioPCM of Q21 and Q23 are more suitable options taking into account that they fully meet the heating needs of the building and in the building cooling section, they reduce energy consumption by 23.4 and 22.1%, respectively. Considering the influence of metabolic rate on PCM usefulness, within the range of 99–180 Watt per person, the addition of PCM to the building led to lower energy demand.