How PVC Warm Edge Spacers Support Long-Term Sealing and Performance If you have ever seen fog forming inside a double-glazed window, you already know what seal failure looks like. It starts small. A little moisture at the edge. Then condensation builds. Over time, the entire insulated glass unit loses performance. Read more. https://m3extrusionpvc.blogspot.com/2026/04/pvc-warm-edge-spacers-long-term-sealing-performance.html