Heat Exchangers with Extended Fins

Better finned tubes for more efficient heat exchangers

Sterling TT offers the integration of a range of extended surfaces to encourage more efficient heat transfer within a heat exchanger. This is done most often by manipulating the tube wall or adding finning, sometimes known as ‘fins’ or ‘finned tubes’.

Fins can be used to produce a more economical final product or for technical purposes, such as size or weight reduction, or improved efficiency and performance.

We offer ‘enhanced finned’ heat exchangers that incorporate extended surfaces, such as:

photo of finned tubes designed and manufactured by Sterling Thermal Technology

  • Sterling TT’s proprietary technology: Elfin and HEI fin
  • LL-fin
  • T-fin
  • NEL fin
  • Spiral and helical wound finned tube
  • Integron

Each of these products has its own strengths. Our Applications team would work with you to select the best for the job.

What is a finned tube heat exchanger?

A finned heat exchanger increases the surface area of the exterior side of the tube to improve the balance of the heat transfer coefficients. For example, we would add fins when a gas is present. Fin style and dimensions are customised to optimise heat transfer.

Enhanced fins

Sterling TT uses extended fins in most of our heat exchangers. We have developed our own technology, Elfin finned tubes, to provide the most effective solution for your needs. We also offer additional solutions such as HEI fins.

We can combine any tube diameter and wall thickness, fin pitch, and a range of materials (e.g. copper-alloys, stainless steel, aluminium, titanium) to help you reach your objective. This could be commercial, cost of ownership, lifetime and reliability, or any combination. Read more about heat exchanger materials.

Whether you need new equipment or retube a heat exchanger, we can help. As we design and manufacture bespoke heat exchangers, we work closely with you to select the best options for your specific application.

Our extended fin technology

Sterling TT offers a range of commercially available extended surface and finned tube integrations, as well as our own proprietary technology. These have been developed in-house for enhanced performance in specific environments and applications.


Elfin offers a broad array of geometries and surfaces, making it ideal for refurbishment and upgrade. It’s also suitable for arduous environments due to the robust fin interference fit.


HEI has limited geometries and surface enhancements but offers very economical solutions for a wide range of air and machine cooling applications.

Reduced fouling

Our expertise of vortex clean air technology reduces pressure loss and fin fouling. This means lower maintenance costs and reduced energy consumption.

Benefits of enhanced performance using finned tubes

Finned tubes can enhance performance in a variety of ways:

  • Increased heat transfer coefficient
    By increasing surface area, a fin increases conduction and therefore improves the efficiency of the heat exchanger.

  • Reduced equipment size
    Enhanced surfaces lead to a larger heat transfer area being attainable within a smaller equipment footprint. Find out more about compact fin heat exchangers.

  • A range of available materials
    We offer materials such as copper, carbon steel, stainless steel, aluminium, cupronickel, and titanium materials. We work with you to determine the best solution for your application.

  • Optimised surface temperatures
    One way to improve efficiency is to increase the temperature gradient. However, increasing surface area is an effective alternative where the cost and sensitivity of materials limit temperature manipulation. Fins, therefore, ensure that temperature-sensitive materials can be processed efficiently.

Applications of enhanced fin tubes

Sterling TT has a long experience in supplying finned heat exchangers suitable for most industries and applications. Whilst each design incorporates components of the highest quality, they are integrated into unique products – from small batches to significant manufacturing runs.

Extended surfaces are often incorporated into heat exchangers since thermal performance on each side of the tube is unlikely identical. One side or the other is treated with enhancements to balance thermal transfer. This is most notably required when there is an imbalanced flow, thermal capacity (particularly between fluids and gas), and temperature differentials are small.

Are you an original equipment manufacturer or an end-user of heat exchangers in your facility? We can help upgrade or replace existing heat exchangers with superior products that include enhanced fins.

If you want to take advantage of our enhanced, finned heat exchangers to improve efficiency, don’t hesitate to contact us.

How we enhance our finned tubes

To design an ‘enhanced finned’ heat exchanger (a heat exchanger with extended fins), we first need to select the ideal configuration that fits your process. We have a wide range of alternatives available, optimised to meet the project objectives. Our engineers would look at the specifics of your application and consider various factors, such as:

  • heat transfer efficiency
  • the impact of fluid viscosity under varying operating conditions
  • potential for fouling

When designing a heat exchanger with fins, it is crucial to consider the thermal efficiency on both the tube side and the finned side of the unit and endeavour to balance the two. The designer will choose the surfaces carefully to ensure maximum heat transfer within the constraints of the available pressure drop allowed in the process design.

We would take these factors, and others, into account while working towards the most economical and lightest construction.

A finned heat exchanger success story

Read a case study on how our enhanced heat exchanger with extended fins was used in a chemical production plant.

The problem

A chemical production plant in the North of England wanted to replace the cores of their existing wire-wound fin air blast coolers. Because they were frequently fouling they needed frequent cleaning, which was damaging the fins and degrading the performance.

The solution: Elfin technology

The client chose Sterling Thermal Technology’s Elfin technology because it combines robust construction and high thermal performance.

We supplied new Elfin cores matching the original material specifications but with the alternative fin construction.

Leading performance and durability

Our customer reported that our units were performing very well and were highly effective. So much so that they compensated for the under-performance of the remaining original finned tube heat exchangers on the same system.

Most importantly, the integrity of the Elfin block eliminated the previous issues of fin damage that frequent cleaning for de-fouling had caused. Unlike many other fin types, you can clean Elfin blocks using a commercial high-pressure water jet.

Like this customer, we think a vast range of processes can benefit from our high-performance finned tubes. If you want to know what we can do for you, don’t hesitate to send us a message.

Are you looking for a partner for enhanced finned heat exchangers?

Sterling Thermal Technology can work with you to consider all aspects of your process. We will offer our best recommendations for an efficient and cost-effective solution to your heat transfer requirements.

If you feel you need another type of heat exchanger, visit our products and services page or contact us.

Photo 1 of finned tubes designed and manufactured by Sterling Thermal Technology - Extended surface heat exchanger
Photo 2 of finned tubes designed and manufactured by Sterling Thermal Technology - Extended surface heat exchanger
Photo 3 of finned tubes designed and manufactured by Sterling Thermal Technology - Extended surface heat exchanger
Photo 4 of finned tubes designed and manufactured by Sterling Thermal Technology - Extended surface
Photo 5 of finned tubes designed and manufactured by Sterling Thermal Technology - Extended surface heat exchanger
T-fin tubes designed and manufactured by Sterling Thermal Technology

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Sterling Thermal Technology supplied units that perform very well and are highly effective. So much that they are compensating for underperforming existing heat exchangers in the same system eliminating the immediate need to replace these older units.

Manager from a chemical production plant in the North of England

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