LAUSR

Abstract The nearly zero energy building (NZEB) is known for the low energy demand and better thermal insulation, thus it is promising to explore the thermal storage potential, and the flexible thermal storage characteristics. In this research, a novel floor integrated with thermal storage enhancement material - micro encapsulated phase change material (PCM), and the ventilation loops, is built in a demonstrated NZEB. A contrast floor with the same ventilation system, but is made of common concrete, is also built in another room with the same envelope. The impacts of solar radiation, PCM and ventilation on thermal storage and space heating performance are investigated by conducting a series of experiments. The results show that for the floor with PCM, the thermal storage capacity is increased by about 77.36%, and the thermal stability of space is also improved. Ventilation can increase both the peak and minimum air temperature by more than 0.5 °C as compared to the case without ventilation. Besides, under the current experimental conditions, ventilation can also significantly increase the space heating and cooling rates by more than 16.7% and 12.6%, respectively, which is meaningful for the flexible operation of the heating systems. In the last, it is found out that solar radiation can increase the space air temperature by more than 3.0 °C in PCM room in the daytime, and the space air temperature at night is also increased by about 0.3 °C if ventilation system works at night.