Google reviewsLined & Double-Wall Duct
Lined and double-wall ductwork for projects with defined thermal, acoustic and construction requirements. Pro Duct fabricates round and rectangular assemblies, with insulation, dimensions and connections reviewed against your project specifications before production begins.
From Pro Duct’s supplied company photo collection.
Duct insulation changes more than the appearance of a section. It affects the clear opening, finished dimensions and the way an assembly is built. Pro Duct fabricates lined and double-wall duct in both round and rectangular forms, helping contractors source these assemblies locally in the Tri-Cities. We start with your specified liner or insulation, material and dimensions. That lets us review the construction as a complete piece rather than treating insulation as an afterthought once the metal has been formed.
Fabrication options
- Internally lined rectangular duct
- Lined round duct
- Double-wall spiral pipe
- Double-wall rectangular duct
- Lined elbows and fittings
- Insulated transitions and connecting sections
What internal lining contributes
Duct liner can absorb sound within an HVAC air path and reduce heat transfer through the duct walls. Its suitability depends on the product and application. Include the specified material, thickness and performance requirements in your request. Liner occupies space inside the shell, so the drawing must distinguish the clear opening from the outside dimensions of the fabricated metal section.
A closer look at double-wall construction
A double-wall assembly uses an inner metal wall and an outer shell, with the specified insulation between them. The project determines the inner-wall construction and insulation details. We manufacture both spiral and rectangular double-wall duct. Send the complete assembly requirements so we can review inner dimensions, outer dimensions, fitting transitions and the connections needed where sections meet.
Keep the specification consistent through fittings
Elbows, offsets and transitions need the same level of detail as straight duct. Insulation thickness and connection geometry can affect the space available around an obstruction or equipment opening. Mark any changes in construction on your drawings and include the matching fittings in the order. We will review these junctions with you before confirming the fabrication details.
What to send us
- Clear inside dimensions and available outside space
- Liner or insulation type and thickness
- Inner and outer material requirements
- Fitting schedule, connections and quantities
- Project specifications and requested completion date
Common questions
What is the difference between lined and double-wall duct?
Lined duct has insulation applied inside a metal shell. Double-wall duct uses inner and outer metal walls with insulation between them. The specified assembly determines its suitability for the application.
Does every duct system need internal liner?
No. Thermal and acoustic requirements vary, and some applications need a different construction. Follow the mechanical design and product requirements for the system.
Can lined HVAC duct be used for kitchen grease exhaust?
Do not assume standard lined HVAC duct is suitable for grease exhaust. Commercial kitchen exhaust needs its own system design and construction review. Send the grease-duct specifications for that project.