Spiral Manufacturing supplies high-quality PVS-coated underground duct and pipe, designed for durability in harsh underground environments. Our insulated metal HVAC ductwork is protected against corrosion, moisture, and other challenges common to subterranean installations, ensuring long-lasting performance. Ideal for commercial and industrial applications, these ducts maintain system efficiency while minimizing maintenance needs. As trusted underground ducting suppliers, Spiral Manufacturing delivers reliable solutions for HVAC systems, providing superior insulation, structural integrity, and protection against environmental wear for safe and efficient airflow management.