The use of phase change materials for buildings cooling is among the most investigated techniques to improve their energy efficiency. This paper presents experimental investigations of a dual-stack latent thermal energy storage system for cooling applications in buildings. The latent energy storage consists of two PCM stacks placed in parallel. Two main design configurations of the storage are investigated based on the use of flow straightening components installed before the PCM stacks.

The overall pressure loss through the energy storage system, pressure distribution before and after the PCM stacks, and thermal performance of the system during charging and discharging cycles are reported. The results show that the pressure distribution is relatively uniform within the inlet and outlet pressure chambers. The overall pressure loss through the system is below the design constraint of 180 Pa for both configurations for a successful integration with commercial ventilation systems. The fraction of air flow going into the PCM stacks for design 1 is ∼55% in stack 1 and ∼45% in stack 2 during both charging and discharging cycles. For design 2 (both sub-designs), the fraction of flow going into stack 1 is ∼65% during both charging and discharging cycles. The design using two PCM stacks achieved high heat storage effectiveness (0.89 for design 1, while it is 0.86 and 0.90 for the two sub-designs of design 2).