APPLICATION AND VERIFICATION USING A MODEL HOUSE

Replacement model of phase change building materials for heat load calculation

Abstract

 In this research, a simple heat load calculation method that employs phase changing material (PCM) replacement model for outer or inner thermal storage wall, ceiling, and floor is proposed.

 Chapter 1 describes the purpose of this research. It is proposing a simplified method to calculate room temperatures and heat load for a model house that contains PCM in its outer or inner thermal storage wall, ceiling or floor.

 The proposed simple calculation method is suggested in Chapter 2. Regarding the replacement of PCM with internal thermal mathematical models for adjoining rooms, we note that the replaced PCM temperature and room temperature affect each other. The proposed model assumes that PCM absorbs solar radiation heat.

 In Chapters 3 and 4, the calculation results for 1,728 replacement model cases were verified and compared to a detailed calculation method, and the accuracy of the simplified method was confirmed. Therefore, it was confirmed that, for cases where the PCM phase change temperature was higher than the set heating temperature, room temperature results with the replaced model demonstrate a tendency similar to that of the detailed calculation. Differences in room temperature results were because the timing of the end of the phase change sometimes differed between the detailed model and the replacement model. However, the phase change timing differences were not significant, and its effect on the annual room temperature was limited. The detailed calculation and replacement model results in the heating and cooling load also indicated similar trends. Conversely, cases where the PCM phase change temperature is not higher than the set heating temperature, differences between the detailed calculation and the replacement model for room temperature and heat load were significant because the replacement model assumes that PCM absorbs solar radiation heat rather than heat from the air in the room.

 As discussed in Chapter 5, there are some issues involved in applying this replacement model to the thermal load calculation of a house.