Two solution methods of heat transfer with phase change within whole building dynamic simulation

The aim of the presented work is to compare two solution methods of specific and latent heat transfer in building components e.g. walls, ceilings or floors. The effect of latent heat storage results from one or more layer made from composites with heighten heat accumulation. This additional heat accumulation follows that the selected layer is modified by incorporating Phase Change Materials (PCM) into its porous structure. The thermal behavior of phase change storage composites has been studied using numerical techniques. Low-temperature thermal wall has been examined as an internal layer of the identical test cells with the same heating and cooling control system, with set points over and under phase change temperature range. This strategy caused the storing and releasing of heating energy from phase change material (PCM) composites. The temperature of composites and latent heat flux have been estimated using the refined ESP-r system with two additional PCMs modeling procedures. First procedure is based on the so-called “Effective Heat Capacity” method, introduced additional, temperature dependent functions of material capacity. The second method the so-called “Additional Heat Source” method assumed some internal heat source will correspond to latent heat stored or released by material. Both methods have been implemented in an ESP-r system and applied for building components. The behaviour of PCMs is modelled using ESP-r’s special materials facility. Numerical analyses have been conducted for two types of PCM-composite layers built in multilayer constructions. The temperature results of the one-dimensional heat transfer process for both cases have been compared and discussed.