Energy Savings Potential of Phase Change Material Integrated Building Envelope in South Texas

The performance of phase change material (PCM) integrated building envelope in terms of peak load reduction, peak load time delay and thermal demand improvement was investigated for a prototype detached single family house in a hot climate location. Five market available PCM layers, which can be easily inserted into traditional wall construction, were selected and coupled into different walls and different locations within the wall. Annual simulation results from EnergyPlus indicated the significant effect of PCM integrated envelope for the studied case. The PCM layer of melting temperature of 23 C is determined as the best one for south wall implementation. When it is placed to the interior of the insulation component of the wall, heat flux at heating load peak is reduced by 22.3% and heat flux at cooling load peak is reduced by 12.3%. For ceiling application, the best performing one is the PCM layer of melting temperature of 25 C and when it is placed below the insulation component of the ceiling. Reduction in peak heat flux is 30.2% for heating and 25.8% for cooling. The greater reduction in peak heat flux of ceiling than south wall is due to its larger area. For peak heat flux time delay, all PCM cases show similar effect of about 30 minutes for typical heating time and 60 minutes for typical cooling time. The performance of PCM layers in reducing annual thermal demand is not as evident as in heat flux: reduction in heating demand ranges from 7.9% to 54.34% and reduction in cooling demand ranges from 1.2% to 7.2%.