SFL Flues & Chimneys
Pottington Business Park
EX31 1LZ

+44 (0)1271 326633 Contact us Today british


+44 (0)1271 326633

British-Built Warm Air Flue Systems From SFL

Flue Systems For Warm Air Heaters

Typically, warm air heaters have two different branches, both heat and discharge air with the aid of a burner, heat exchanger and axial or centrifugal air supply fan.

High-level individual unit heaters will be flued vertically through the building roof or horizontally through the wall, many types of unit heaters have the facility to bring combustion air directly from outside via the flue, these “balanced flue” units are gaining popularity with installers as they easily meet building regulations.

Advanced gas and oil fuelled Warm Air heaters are mainly supplied with In-shot or the latest Premix, low NOx high-efficiency burners. Modern burner control technology provides on/off, high/low or fully modulating control creating new flue and chimney requirements.

Important Considerations

Performance of the appliances can be significantly affected by incorrect flue design and many other factors including:

  • Heater location and flue run outside
    Flue system and design must have the flexibility to match the heater location within the building, giving an achievable, safe and cost-effective exhaust system.
  • Condensing & high efficient heaters
    Ensure the system has the correct seals and joint clamps to minimise leaks and joint failures.
  • Achieving the desired efficiency
    The system should be matched perfectly to the specified type and fuel of the warm air unit heater maximising efficiency and controllability.

Why choose SFL?

We are proud of our British built heritage at SFL. All our products are fabricated at our manufacturing centre in Barnstaple, Devon, UK. As well as investment in the latest manufacturing system, we also have an extensive R&D centre ensuring continuous product development and testing to the latest European standards.

UK Flag

British Built

UK manufactured flue & chimney systems.


Full Design Support

Get expert design assistance & full turnkey package support.


Industry Expertise

With over 50 years experience, you are in expert hands with SFL.

Successful project delivery, no matter the challenge.

We’re committed to offering industry-leading support services. That’s why SFL can provide full technical support throughout the whole process of design, manufacture, and supply of your upcoming project. From initial product selection from our British-built systems range to complete design and calculations. SFL work with carefully selected installation teams to ensure your turnkey package is carried out on time within budget by seasoned professionals.

Suitable Systems


Twin Wall Flue System


NOVA® insulated twin wall system, a superior, U.K designed, engineered and manufactured flue for quality domestic installations. With its uniquely robust multi barb speedy twist lock jointing system, it's trusted and favoured by installers around the globe. A wide range of components makes any installation a possibility.


Single Wall Flue System


SUPRA® is our single wall stainless steel chimney system designed with the commercial installer in mind. Pre-fitted seals make it a go-to product for any commercial condensing and positive pressure applications.

SUPRA PLUS® is our single wall stainless steel chimney for 80mm to 350mm diameter systems.

SUPRA XL® is our single wall stainless steel flue and chimney for 400 to 600mm diameter systems.

Need technical design assistance?

Let's discuss your project

Our team of experienced commercial flue experts are on hand to assist you at every stage of your project. Support includes product selection and application advice including existing system surveys and advice. Working with key installation partners we can provide you with a bespoke customised turnkey package.

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