LHM(latent heat materials) have been well known as one of the heat storage materials. Recently prefabricated buildings consisting of insulator to apply LHM have been conducted in many studies. In case that apply LHM to a building wall, that has a effective performance in thermal insulation.
This study is basic research that aim to meet conditions(indoor temperature, maintaining time for goal) on design of multi-layer wallboard by building designer. Indoor thermal environment were observed due to thickness of LHM and insulator, position of LHM, presence of LHM and changes in mean temperature of heat source using multi-layer wallboard in periodic heat load condition. In the constant heat flux condition, maintaining time of indoor temperature were observed due to thickness of LHM. Also, for maintaining the target indoor temperature, appropriate thickness of multi-layer wallboard is confirmed.
In this study, we experimented and simulated to investigate the change of temperature in multi-layer wallboard under various conditions such as thermal characteristics of latent heat material and different wall thickness. By 1-dimensional transient heat transfer analysis, indoor temperature changes were confirmed under constant heat flux condition.
In the experimental set up, heat flux and temperature of heater was controlled to confirm a heat transfer mechanism of multi-layer wallboard. The results under periodic heat load condition were confirmed that when the LHM is present, when the LHM located in the inner, when the mean temperature of heat source temperature similar to phase change temperature and case of increasing in thickness of LHM were more effective. And the result under constant heat flux condition, maintaining time of target indoor temperature increased due to increase in thickness of LHM. But degree of increase were reduced because of constant supplied heat transfer rate (16.65W). In the thermal characteristic analysis of multi-layer wallboard, to maintain the designed target maintaining time (8hr), appropriate composition ratio of multi-layer wallboard is 15 mm LHM and 5 mm insulator. In case that consist of only insulator, it needs 307 mm for target indoor temperature maintaining time. Comparing to multi-layer wallboard, insulator wall needs more thickness of 287 mm.