Evaluation of the energy flexibility potential of radiant ceiling panels with thermal energy storage

This study focuses on evaluating the energy flexibility potential of an innovative cooling technology that consists of a standard radiant ceiling panel incorporating macro-encapsulated phase change materials (PCM). The incorporated PCM allows shifting the energy demand for building cooling. A simulation case study is implemented to investigate the energy flexibility of an office building conditioned by the proposed system in a hot and humid climate. At first, the thermal storage properties of the macro-encapsulated PCM were determined by using the standard ASTM C1784-20. The obtained properties were then used in a whole-building simulation model validated using measurements in a real size walk-in chamber. Three different performance indicators were used to quantify energy flexibility: available storage capacity, storage efficiency, and power shifting capacity. Results show that with an average panel to ceiling ratio of around 66%, the radiant ceiling panel has an average sensible heat storage capacity of around 430 Wh/m2day and average annual storage efficiency of 86%. Results also show that the proposed system can shift the electric power demand for conditioning by 8 h compared to a conventional all-air system. These results confirm the benefit for implementing Demand-Side Management strategies that can exploit the energy demand flexibility of radiant ceiling panels incorporating PCM.