The service lifespan of PVC flexible ducting typically ranges from 10 to 20 years under normal conditions, but it can vary based on quality, installation, usage, and maintenance. Some sources mention up to 50 to 70 years, though this may be under ideal circumstances. Regular inspection and proper maintenance are crucial for extending its longevity, while exposure to extreme heat, chemicals, or physical harm can reduce its life span. It’s important to consult the manufacturer’s guidelines for a more precise estimate.