
High Efficiency Air Distribution
For contractors, architects, and engineers seeking high-performance HVAC solutions, Thermaduct’s outdoor phenolic duct systems deliver unmatched efficiency, durability, and installation simplicity. Engineered for commercial and industrial applications, our pre-insulated phenolic ductwork combines superior thermal performance, weather resistance, and code compliance with a contractor-friendly design that streamlines installation and reduces costs in the field.
With a nationwide network of representatives ready to assist you, Thermaduct are the go-to choice for contractors. Air distribution products are available closer than you think! Read below for more information on all of our systems.
Thermaduct - Outdoor Rectangular Ductwork

Thermaduct Outdoor Rectangular Ductwork
Exterior Rooftop Duct
Duct, Insulation, and Cladding All In One
Thermaduct, a patented rectangular exterior ducting solution has redefined HVAC performance for commercial and industrial outdoor applications. Engineered to deliver superior thermal efficiency, near-zero air leakage, and exceptional durability, Thermaduct integrates ductwork, insulation, and cladding into a single, high-performance system. Designed to meet and exceed SMACNA Phenolic Duct Construction Standards, Thermaduct is the trusted choice for contractors, architects, and engineers seeking reliable, efficient, and code-compliant HVAC solutions.
- R8 Through R24
- 1000 Micron, UV Stable Vinyl Cladding
- Closed Cell Insulation
- Near Zero Air Leakage
- Lightweight
- Fiberglass Free Interior - Smooth Aluminum Interior
- Reduced Embodied Carbon Compared to Metal
- 10 Year Limited Warranty
Thermaduct Videos:
Thermaduct Installation Training - Connection Preview | training.thermaduct.com
Insulated Outdoor Ductwork Installation - Thermaduct Pre-Insulated Exterior Duct System
Thermaduct Rooftop Ductwork - Pre-insulated Phenolic Duct System
5 Reasons to Use Phenolic Pre-Insulated Ductwork
Ductwork Designed for the Elements
Thermaduct has a long history of success in solving headaches associated with rooftop ductwork. For more information on how you can use this system in your installation, please visit our dedicated page.
Thermaround - Outdoor Round Ductwork

Thermaduct Thermaround Outdoor Ductwork
Pre-Insulated Exterior Rooftop Ductwork
Truly Outdoor Duct Solved!
Thermaround, a patented round phenolic duct system is specifically engineered to excel in outdoor commercial and industrial HVAC applications. The round shape of Thermaround offers distinct advantages over rectangular or square duct systems, particularly in outdoor environments where durability, efficiency, and performance are critical. By integrating the same 1000 micron, UV stable vinyl as Thermaduct, our round outdoor ductwork delivers a reliable, contractor-friendly system that ensures long-term performance and cost savings.
- R12 Insulated Value
- Naturally Sheds Water
- 1000 Micron, UV Stable Vinyl Cladding
- Closed Cell Insulation
- Smooth Aluminum Interior - Fiber Free Insulation
- Lightweight
- Near Zero Air Leakage
- Reduced Embodied Carbon Compared to Metal
- 10 Year Limited Warranty

Architectural Outdoor Insulated Ductwork
Insulated Thermaround Architectural Duct
METAL CLADDING - Designed for Aesthetics, Engineered for Performance
For applications where aesthetics play a key role, Thermaround Architectural combines exceptional thermal efficiency, near-zero air leakage, and robust durability with a sleek, architecturally appealing aesthetic. Thermaduct is proud to offer a high quality metal cladded version of our round system to offer contractors, architects and engineers a high performance outdoor duct alternative to enhance functionality and design.
- R12 Insulated Value with Closed Cell Insulation
- Kynar Finished Metal Exterior
- Naturally Sheds Water
- Flanged Connections for Fast Installation
- Lightweight
- Indoor and Outdoor Use
- Reduced Embodied Carbon Compared to Double Wall Metal
- 10 Year Limited Warranty
Thermaround Videos:
Thermaduct Round Installation Training - Connections | training.thermaduct.com
Thermaround Outdoor Insulated Ductwork - Virtually Seamless System for Exterior Applications
Thermaround Outdoor Ductwork - Virtually Seamless, Insulated Round Outdoor Duct System
Thermaround Architectural Ductwork - Custom Colorful Pre-Insulated Outdoor Duct
High Efficiency Round Exterior Ductwork
The quality of Thermaduct pre-insulated ductwork with the added efficiency of round ductwork. For more Information on Thermaround, please visit our dedicated page.
InspiralR & Floval - Indoor Round & Flat Oval Ductwork

InspiralR Floval Preinsulated Round and Flat Oval
Insulated Double Wall Ductwork Alternative
Lightweight Pre-Insulated Ductwork
InspiralR and Floval are our patented indoor round and flat oval solutions that are UL 181 Listed for 10” w.c. positive and 8” w.c. negative applications. InspiralR and Floval are lightweight systems and can offer up to a 75% weight savings versus traditional double wall spiral duct. This ultra low air leakage system also provides an R-6 insulated value. Tight on ceiling space? Floval is your solution as there’s no need to insulate separately!
- UL 181 Listed Round Duct System
- Near Zero Air Leakage
- Made with Pre-Insulated R-6 Phenolic Panels
- Fiber Free Insulation - Smooth Aluminum Interior with No Fibrous Liners
- Lightweight Duct System - Up to 75% Lighter than Doublewall
- Low Embodied Carbon
- 10 Year Limited Warranty
InspiralR and Floval Videos
Simple Pre-Insulated Spiral Duct Connections | training.thermaduct.com
Pre-Insulated Round and Flat Oval Phenolic Ductwork - Thermaduct InspiralR and Floval Systems
Thermaduct InspiralR Pre-Insulated Double Wall Spiral Duct System
Thermaduct Lightweight Pre-Insulated Flat Oval and Round Ductwork - InspiralR and Floval
High Efficiency Indoor Products
For more Information on how InspiralR and Floval can help your next application have high efficiency air distribution, please visit our dedicated page.
Thermaduct's Lineset Portal - Efficient Access for Pipe, Lineset and Electrical Conduit

Thermaduct Lineset and Pipe Portal
Insulated Rooftop Portal for Piping and Electrical Conduit Organization
Comprehensive Utility, Customized to fit your application
Our fully insulated portal facilitates the effortless routing of linesets and electrical conduit to rooftop units. Customizable to various curb sizes, the Thermaduct Lineset Portal offers insulation values ranging from R8 to R24, ensuring optimal thermal efficiency. It features the same durable 1000-micron vinyl cladding as our outdoor systems, and employs welded solvent seams to provide superior protection and longevity. This patent-pending design streamlines the installation process and reduces labor hours by as much as 50%, while giving you a professional looking installation.
- Fully Insulated and Weather Resistant
- Multi-Piece Construction
- High Insulated Values - R8 through R24
- Optimized Organization for Piping, Linesets and Electrical Conduit
- UV Stable Cladding
- Low Embodied Carbon
- 10 Year Limited Warranty
Thermaduct Lineset Portal Videos
Insulated Lineset and Pipe Portal - Commercial & Multifamily Buildings - Thermaduct Lineset Portal
Keep Your Application Fully Insulated and Better Organized
For more Information on how the Thermaduct Lineset Portal l can help your next application better address a fully insulated building envelope, please visit our dedicated page.
Additional Information

Pre-Insulated Phenolic Ductwork Applications
All of our duct systems employ a smooth aluminum interior for a high quality, fiber free insulation. Because of this, Thermaduct, Thermaround, InspiralR, and Floval are great for almost any application.
Hospitals and Healthcare Environments
Schools and Universities
Hotels and Multifamily Structures
Commercial and Industrial Applications
Pools and Natatoriums
Products That Offer More for Customers
High R-Values
Low thermal transfer keeps conditioned air at the desired temperatures
Low Air Leakage
Virtually airtight connections deliver more of the conditioned air to their destination
Easy to Install
Lightweight Systems designed to increase efficiency on the jobsite. Do more with less!
Fewer Call Backs
Worry less as Thermaduct products are backed by a 10 year limited warranty
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Thermaduct Product Information
- Thermaduct Product Introduction
- Thermaduct Project Profiles
- Thermaduct Literature Page
- Interior Lining Options
- Lightweight Ductwork
Find A Representative
We work with a fantastic group of representatives all over the country. Find your the local Thermaduct representative in your area here.
