A novel building façade integrated with TIM and PCM: Numerical Study for Summer

Transparent insulation material (TIM) not only is of similar function of opaque insulation but also can allow solar transmittance. Phase change material (PCM) can charge and discharge much heat during the phase change temperature range due to the high latent heat. A novel building façade is proposed by the combination of TIM and PCM and there are no moving parts or only a small fan in the structure. It could be used for residential and commercial buildings, providing heating and cooling for the living space as a sustainable low-carbon building. Fluent is adopted and a simple numerical model is set up to study the thermal performance of the novel structure. The fitted formula of overall transmission with solar incident angle is arrived. The numerical results for summer show that: (1) The average heat transfer rate of the exterior surface of the room wall increases with the increasing inlet velocity for the novel structure while decreases for the reference structure. (2) The ventilation heat transfer rate changes little with the increasing inlet velocity for the novel structure while increases for the reference structure. (3) When the inlet velocity is higher, the difference between the novel and reference structures is smaller. (4) The effect of Tm on the ventilation heat transfer rate is higher than that on the average heat transfer rate of the exterior surface of the room wall. (5) The suitable phase change temperature is 308-310K when the inlet velocity is 0.5 m/s and the corresponding total heat transfer rate can be decreased by 33.8% compared with that when Tm is 303-305K.