The purpose of this research is proposing a simplification method of calculation for temperature of rooms without air conditioning by using a replacement model of Phase Change Materials (PCM) at inner thermal storage wall and floor.
Chapter 1 is about previous studies and the purpose of this research. Numerous researches were discussed about PCM calculation. However, the previous studies divide PCM into small parts and it is not practical for case study in a design process. Therefore, it is useful to simplify of calculating room temperature of a building model that contains PCM in its wall or floor.
In Chapter 2, the method of simplification of calculation is suggested. It is for temperature of a simple building model without air conditioning that contains PCM in its inner wall or floor. Regarding replacement of PCM with furniture model of adjoining rooms, replaced PCM temperature and room temperature effect on each other. PCM distribution ratios which indicate ratios of PCM distributed into two replaced PCM of adjoining rooms, distribution ratios of solar radiation inside the rooms which indicate ratios of solar radiation distributed to parts inside the rooms including replaced PCM, thermal resistance between room temperature and furniture are decided depending on given conditions. The values of distribution ratios of solar radiation with replaced PCM are calculated from surface heat transfer coefficient, heat transmission coefficient of the inner wall, heat transmission coefficient between the surface of the inner wall and PCM, and inner solar radiation distribution ratio without PCM. Then, PCM distribution ratios are calculated from distribution ratios of solar radiation with replaced PCM. Moreover, the resistances between room temperature and replaced PCM are decided according to the resistance between surface of the inner wall and room air, the resistance between surface of PCM and room air and others.
In term of comparison result, in Chapter 3, the calculation result of 1728 cases of replacement model was verified compared with detailed calculation, and accuracy of simplification was confirmed. As a result, it confirmed that, even in the case that difference of room temperature of detailed calculation and replacement model is the most significant, room temperature of replacement model showed similar tendency with detailed calculation. In other words, the difference of the highest and lowest room temperature for each day between detailed calculation and replacement model is less than 2°C about representative days of the case that difference of room temperature of detailed calculation and replacement model is the most significant. In addition, about the case, the timings of the highest and lowest room temperature of replacement model do not shift so much from that of detailed calculation.
However, there are some issues to apply this replacement model to thermal load calculation of a house. The issues are referred in Chapter 4. In the future, replacement model needs to be extended to a model for air-conditioned condition, a house with more than 2 rooms with PCM in outer walls.
