The pvc coating on the fabric provides a layer of protection that protects against stains and mildew, which can be a big advantage in these types of environments. The coating is also highly durable and able to withstand abrasion, which makes it ideal for dragging or scraping against surfaces in harsh conditions. PVC-coated ducts are also less expensive than metal ducting, making them ... https://www.duletai.com/product/pvc-coated-air-duct-fabric/