Energy saving effect of air circulation heat storage system using natural energy

A central air circulation system that uses a roof ventilation layer and a phase change material (PCM) unit is proposed as a possible means of controlling thermal load and peak load. The central air-conditioning air-circulation-type system enables reduction of sensible heat load and facilitates radiative cooling/forced heat exchange in summer, and solar heat collection in winter, via the roof ventilation layer; thereby improving efficiency. The PCM unit is incorporated into the air circulation route to store the cold energy of the cooled air by radiative cooling and the heat energy of the heated air by solar heat collection. The actual measurement results of an experimental house were analyzed and numerical simulations were performed to evaluate the effective sensible heat and peak load reductions. The quantitative simulation and experimental results indicate that significant sensible heat reduction can be achieved by employing the proposed system, which uses natural energy to reduce the energy consumption of indoor temperature control.