Ochiai, N.; Sagara, K.; Yamanaka, T.; Kotani, H.; Momoi, Y.; Kaneko, Y.
Bibliographic info:
29th AIVC Conference " Advanced building ventilation and environmental technology for addressing climate change issues", Kyoto, Japan, 14-16 October 2008

This paper presents a study of solar chimneysusing a Phase Change Material (PCM)integrated into the heat absorber of the solarchimney. Solar chimneys have recently beenused as natural ventilation devices in buildingsin order to improve the quality of indoor airand provide a comfortable environment for theinhabitants. The advantage of a solar chimneyis that it depends on solar energy rather thanelectricity for generating ventilation. However,it is unstable as a ventilation system since itsventilation rate is directly affected by the solarradiation. In order to solve this problem, themethod of incorporating PCM into the solarchimney was developed and its usability hasbeen investigated in previous studies. Thispaper focuses on the characteristics of PCM,especially on the super-cooling during thesolidifying process. Experiments wereconducted to understand the therrnophysicalproperties of PCM and numerical simulationswhich take the effect of super-cooling of PCMin consideration were developed. Further, amodel for predicting the ventilation rate of thesolar chimney with built-in PCM wasdeveloped and the simulation results werecompared with the experimental results inorder to evaluate the accuracy of the model.