Enhanced long-term thermal performance prediction of glass wool vacuum insulation panels: A comprehensive accelerated testing approach

Vacuum Insulation Panels (VIP) with glass wool cores represent an innovative insulation technology offering excellent thermal performance; however, their long-term effectiveness inevitably degrades due to gas and moisture permeation through the envelope. This study proposes an accelerated test protocol to overcome limitations of existing standard methods for evaluating the 25-year long-term thermal performance of glass wool VIP. Three evaluation methodologies were systematically compared: Strategy A tracked natural aging under standard conditions (23°C, 50% RH) for 1,100 days; Strategy B followed the ISO 16478 protocol with 180-day testing under three accelerated conditions; and Strategy C employed optimized conditioning at a single accelerated condition (80°C, 70% RH), with the test duration determined by comprehensively considering acceleration factors for both dry air and water vapor permeation. The optimal conditioning period of 70 days for Strategy C was derived from the combined acceleration effects, representing the time required under accelerated conditions to simulate 25 years of standard service performance. All three strategies predicted thermal conductivity values after 25 years that met ISO 16478 requirements. Strategy C effectively reduces evaluation time while enabling integrated assessment of dry air permeation, water vapor infiltration, and absorbents performance, addressing the complex degradation mechanisms not fully captured by current standards.