Optimization and cost analysis of thickness of vacuum insulation panel for structural insulating panel buildings in cold climates

Abstract

Structural insulation panels (SIPs) are considered promising building products that achieve the low-energy goal, and its potential energy performance can be further improved by combining it with a vacuum insulation panel (VIP) in cold climates. The aim of this study is to determine the optimal SIP with VIP (VIP–SIP) thickness and to minimize the energy cost. We conduct a VIP-SIP thickness optimization and cost analysis for five cold sub-regions using P1-P2 methods. First, we develop an energy model using the building energy simulation software OpenStudio considering the VIP aging effect, and the accuracy of this model is validated using field test data. Results indicate that as climates become colder from Cold area B to Severe Cold area A, the optimal VIP thickness increases from 3.5 mm to 31 mm, whereas the optimal PU thickness decreases from 66.875 mm to 174.2 mm. In addition, the total cost saving rate increases from 40.5% to 47.9%, and the discounted payback period decreases from 12.59 years to 8.98 years, indicating improved economic feasibility. Furthermore, the influence of the P1 value and VIP price on the optimal thickness and total cost are also discussed. The findings of this study confirm the economic feasibility of combining SIP with VIP in cold areas, and provide feasible parameters for the design of low-energy buildings in cold areas of China.