Round Rooftop Spiral Duct System

Thermaround Outdoor Ductwork System


Thermaround is our patented system that takes the best parts of our Thermaduct™ system to have a more streamlined and aerodynamic shape for outdoor dynamic loads. As a non-metal alternative to spiral or round rooftop ductwork, Thermaround is a pre-insulated solution that offers your duct, insulation and cladding all in one high efficiency duct product. Strong flanged connections allow this round solution to install fast and easy. Thermaduct's patented process allows for a continuous cladded surface with as few as one solvent welded seam!

With a standard vinyl cladding that offers the same weather resistant protection as rectangular Thermaduct, Thermaround is an excellent lightweight solution for the outdoor elements. This high R-value thermal system offers an R-12 insulated value and extremely low air leakage. Thermaround is also available with multiple cladding options with both our vinyl or architectural metal for a durable solution that will naturally shed water. In the interior, air passes over a smooth aluminum phenolic insulation surface free from loose fibers to give your building better IAQ performance.

Round Thermaduct Outdoor Ductwork

Features for Outdoor Applications:

  • Patented Product
  • High R-values - R12 Insulation Values
  • 10" Positive, 8" Negative Pressure Class
  • UL 181 Listed InspiralR Interior
  • 1000 Micron UV Stable Vinyl Cladding
  • High Static Pressure Design
  • Lightweight Duct System
  • Gored Elbows - No Need for Turning Vanes
  • Low Air Leakage Rates - Easily Achieve a SMACNA Class 3 or Better
  • Pre-assembled Easy to Install, Fast Connections

Thermaround is an award winning outdoor duct solution highlighted in:

Outdoor Duct Systems in Rectangular and Round

Factory Laminated & Virtually Seamless Vinyl Cladding

With a continuous cladded surface, Thermaround virtually eliminates common areas of water intrusion. Our 1000 micron, UV stable vinyl clad is factory applied to our closed cell insulation with a full lamination process for a permanent bond. This strong barrier keeps outdoor elements out and conditioned air in to ensure high efficiency air distribution.

Duct sections are designed to have as few as one solvent welded seam for an uncompromising protective surface that requires no field installation of cladding.

Pre-Insulated Spiral Duct Systems – Thermaround

Outdoor Efficiency - Designed with Architects in Mind

Whether your application is looking for “cool roof” efficiency or just “cool” colors, Thermaround is now available with an optional Kynar finish sheet metal cladding. This opens up more opportunities for architectural application where the look of your ductwork play a key role in building design, while still allowing for the pre-insulated industry-leading durability and thermal quality of Thermaround.

Find out more about our Architectural Options

Near Zero Air Leakage

Energy Efficient Air Distribution Perfect for Exterior HVAC Systems

Preinsulated System

Our high performance solution provides superior thermal performance with an R12 insulated value without the need for additional duct insulation

Ease of Installation

With Thermaround's lightweight duct and fast connection system allow you to install more outdoor duct per day

10 Year Limited Warranty

Thermaround is backed by a 10 year limited warranty

Thermaduct and Thermaround Kingspan KoolDuct Fortified with 1000 micron vinyl Thermaduct

Pair Easily with Thermaduct Outdoor Rectangular Ductwork

Thermaduct and Thermaround both provide a factory laminated surface with a minimal areas susceptible to water intrusion. Applications that require both round and rectangular ductwork will find no better exterior ductwork solution than our outdoor products.

Both products install easily and provide near zero air leakage. Our patented Thermaround system requires installing contractors to apply sealant, connect sections together with an offset coupling and use a draw band connection for fast and easy installation. With online training to assist contractors in feeling comfortable with our systems, it's never been easier to use phenolic outdoor ductwork!

Thermaduct and Thermaround truly are Outdoor Duct Solved!

Thermaround Project Case Studies

Below are highlighted applications from our Family of Product Case Studies

 Pharmaceutical Facility

Thermaround played a role in helping a Massachusetts pharmaceutical facility meet it's decarbonization goals and increase the efficiency of their building.

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Downtown Boston Hotel

Located near the waterfront of Boston Harbor, this facility had a large portion of their HVAC system designed outdoors, exposed to the elements.

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Montana Multiphase Hospital

Thermaduct products were the duct solution of choice for both phases of this hospital's R-12 pre-insulated HVAC system upgrades.

Read More

See Thermaround In Action

2022 Thermaduct Round Installation Training - Connections |

Thermaround Outdoor Insulated Ductwork - Virtually Seamless System for Exterior Applications

Thermaround Outdoor Ductwork - Virtually Seamless, Insulated Round Outdoor Duct System

Thermaround Exterior Ductwork at Medical Production Facility - Virtually Seamless Spiral Alternative

Thermaround Corrosion Resistant Rooftop Ductwork - Coastal Hospital Pre-Insulated Outdoor Duct

Vinyl Cladded Phenolic Ductwork

Thermaround Exterior Duct System

Non-Metal Insulated Ductwork

Insulated Metal Ductwork Alternative

Phenolic Ductwork Rooftop

Outdoor Duct System

Thermaround Phenolic Outdoor Duct

Thermaround Outdoor Ductwork

Thermaduct R-12 round ductwork

Exterior Pre-Insulated Ductwork

Thermaduct's Thermaround Pre-Insulated Ductwork

Thermaround Vinyl Cladded Duct

Outdoor Ductwork - Thermaround Phenolic System

Thermaround Outdoor Ductwork

preinsulated round ductwork outdoors

Thermaround Healthcare Outdoor Seamless Spiral Duct Alternative

thermaround insulated spiral ductwork

Thermaround Hospital Outdoor Round Ductwork Oregon

Thermaround Outdoor Round Ductwork

Thermaround Doublewall Outdoor Spiral Alternative

preinsulated outdoor ductwork

Thermaduct Round Rectangular Outdoor Ductwork

Hospital Exterior Rooftop Spiral Duct

Thermaround Outdoor Hospital Ductwork

Thermaround Outdoor Pre-Insulated Phenolic Ductwork

Thermaround uses a smooth aluminum Kingspan KoolDuct interior for a high quality, fiber free insulation that is protected by our 1000 Micron vinyl cladding. Because of this, our round outdoor duct system is great for almost any ductwork applications.

Hospitals and Healthcare Environments

Schools and Universities

Hotels and Multifamily Structures

Commercial and Industrial Applications

Pools and Natatoriums

Phenolic Duct Installation

See How Thermaduct Products Install in the Field

While our products will feel very familiar to traditional exterior insulated ductwork, we have a brief online training course to cover the differences that should be observed when installing an outdoor phenolic duct system.


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Thermaduct Outdoor and Indoor Product Information

Find A Representative

We work with a fantastic group of representatives to provide exterior and interior systems all over the country. Find your the local Thermaduct representative in your area here.

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