Effect of Summer Ventilation on the Thermal Performance and Energy Efficiency of Buildings Utilizing Phase Change Materials

Abstract

Abstract:To analyze the effect of summer ventilation on the thermal performance and energy efficiency of buildings utilizing phase change materials (PCMs), this paper simulated the indoor temperature variation and energy saving performance of buildings constructed with PCM under different ventilation conditions from June to September. With EnergyPlus and degree-day method, 48 ventilation schemes, including eight ventilation periods (3 h per period) and six ventilation quantities (0.5 ac/h to 3 ac/h), were modeled and simulated in five cities located in different climate regions in China. According to the results, it is believed that the simultaneous use of PCM and ventilation can significantly improve the indoor thermal comfort and offer a good energy saving performance in summer. Considering the economic benefits, different optimal ventilation schemes (including ventilation periods and ventilation quantities) were suggested for different climate regions.

Numerical assessing energy performance for building envelopes with phase change material

“…EnergyPlus with the CondFD algorithm can simulate materials with varying thermal and thermal conductivity with temperature, so it is used in simulation analysis of building envelope with PCM. Rigorous validations and verification studies for heat transfer calculations of PCMs in EnergyPlus have been performed by many researchers . So EnergyPlus was used in this paper to calculate the energy performance of building with PCMs as its envelopes, and we followed some guidelines for using the PCM module in EnergyPlus recommended by Tabares Velasco et al…”

Comparative Research on Solar Phase Change Material Storage Wall Systems under Different Summer Working Conditions

“…Zhou [5] established a south-facing direct-gain room with shape-stabilized phase change material (SSPCM) model and discussed the selection criteria of some parameters such as phase change temperature, and latent heat. Zhang [6] simulated the indoor temperature variation and energy saving performance of buildings constructed with PCM under different ventilation conditions in varying ambient conditions (June to September). Different optimal ventilation schemes were suggested for different climatic conditions.…”

“…Passive cooling mode: when the building needs thermal insulation protection during nighttime, e.g., in summer nighttime, the indoor upper and lower vents (5,6) shut while the middle layer ones (3,4) and the outdoor ones (1,2) open. Primarily under the action of ambient wind pressure, circular flow forms between internal channel and external channel; the relatively cool outdoor air during the nighttime cools down the PCM wall.…”

“…It is mainly composed of PCM wall, thermal insulation wall, interior and exterior flow channels, heat absorbing aluminum plate covered by selective absorption coating, indoor upper and lower vents (5,6), outdoor upper and lower vents (1,2), middle layer upper and lower vents (3,4), glass cover and frame. The system is installed on the south-facing vertical surface of the building.…”

“…Heat insulation mode: when the building needs the protection of thermal insulation in daytime, e.g., in summer's daytime, the indoor upper and lower vents (5,6) and the middle layer ones (3,4) shut while the outdoor ones (1,2) open. The combination of ambient wind pressure and thermosiphon pressure forms a circular flow between the external channels and the outdoor air that brings the solar energy absorbed by the aluminum plate back to the environment; meanwhile the inner air channel acts as heat protection between the thermal insulation layer and the south wall of the room.…”