The insulation requirements for buildings are being strengthened to make zero energy mandatory. Vacuum insulation panel (VIP) has about 8~10 times better insulation performance than existing insulation and also maintains high insulation performance with a slimmer thickness. However, when VIP is installed on a building wall, thermal bridge occurs. Thermal bridges of VIP itself, thermal bridges due to air gaps between adjacent vacuum insulation panels, and thermal bridges with other building materials that make up the walls. Thermal bridges deteriorate the insulation performance of the building envelop. The purpose of this study is to compare and analyze the insulation performance by designing a wall with vacuum insulation panels and applying a method to improve the insulation performance degradation due to heat bridges.
In this paper, thermal bridge phenomenon of the wall was analyzed using physibel TRISCO simulation program. The walls were designed for VIP application walls and VIP encapsulated EPS insulation application walls. The parameters of thermal bridges reduction were set to airgap seals between VIPs, application of thermal bridge fastener and both. A total of 8 cases were designed.
Based on the simulation results thermal bridge effect for Case 1 (air layer effect) reduced by 11.7%, Case 2 (heat bridge interception fastener effect) reduced by 10.5%, and Case 3 (air layer enclosure and heat bridge interception fastener) reduced by 40% compared with the base model. Likewise, thermal bridge effect for wall with encapsulated VIP reduced by 5.2% for Case 1, 7.2% for Case 2, and 13.6% for Case 3. As a result, it was confirmed that the airtight seal and the type of connection material affect the thermal bridge reduction.
Considering Case 3, whereby thermal bridging method was applied, the effective heat conduction rate of the encapsulated VIP wall increased as the length of the fastener increased. The effective heat conduction rate was higher than that of general VIP applied wall. However, it was deduced that encapsulation is necessary to protect VIP damage and internal vacuum when applied to buildings. From the findings in this paper, it is recommended that necessary techniques are adopted to prevent deterioration of insulation performance primarily due to thermal bridges. In the future, practical application and examination of VIPs in building applications is required.