Thermal storage and thermal management properties of a novel ventilated mortar block integrated with phase change material for floor heating: an experimental study

Integrating micro-encapsulated phase change material (PCM) in mortar could enlarge thermal storage capacity of building thermal mass, however the reduction of conductivity would slow down thermal response. This article proposes a new method by integrating ventilation loops in floor heating phase change material mortar blocks to enhance the energy flexibility, and achieve thermal management. Experiment was carried out to test the thermal and energy performance of a series of ventilated cement based mortar blocks integrated with micro encapsulated phase change material. The amount of phase change material in each block was the same but the distribution patterns were different, including upper concentrated, lower concentrated and evenly distributed. Three heating scenarios including single heating, ventilation-heating and intermittent heating were conducted. Results indicated that the distribution of phase change material had strong influence on the thermal storage and heating performance. In single heating scenario, compared to pure mortar block, phase change material blocks could increase 11.4% - 18% heating power consumption. In ventilation-heating mode, the outlet air temperature was higher than the space air, which confirmed the inner space ventilation potential. Ventilation could also prolong the required heating time and enlarge 7.4% - 13% power consumption of phase change material mortar block, and reduce 22.7% - 25.6% cooling time. Especially in intermittent heating mode, the space heating performance of partially concentrated phase change material blocks were much better. Thus, the thermal storage capacity and energy extraction flexibility of the ventilated mortar blocks integrated with phase change material were validated, and partially distributed phase change material mortar blocks showed better thermal performance than evenly distributed phase change material mortar block.