Research on the reduction effect of the space heating load by latent heat storage interior building material: Examination by a model box experiment, a test house experiment, and a numerical simulation

The phase-change characteristic of PCM and the influence of phase-change thermal storage on indoor thermal environment and heatingload were examined with the aim of effective utilization of solar heat by model experiments, outdoor experiments and numerical simulation. The main results obtained are as follows. In the model experiment, the basic data on PCM amount and construction area to keep the room temperature constant are obtained. In the outdoor experiments, the heating load during the night was reduced by up to 9.6% in sunny day by apparent effects of heat storage on PCM constructed in the floor of test house. In addition, the horizontal distribution of room temperature was moderated by relieving cold drafts from windows with temperature rise of the PCM constructed floor. It was confirmed that the simulation software 'THERB for HAM' can accurately calculate the actual indoor thermal environments through the comparison with experimental results. Sensitive analyses on heating load for a single-family house utilizing THERB and multiple linear regression analyses with calculation results clarified that the construction area of PCM, the temperature difference between melting point of PCM and heating preset temperature, the heat loss coefficient of buildings, the constructed amount of PCM have a profound effect in sequence on the heating load and then those contributory factors are crucially important in the development of PCM building materials and solar heat utilization houses.