Which Material is Best for your Coil?

Colby Maun • July 27, 2026

In commercial HVAC, one of the largest yet overlooked aspects of a custom coil replacement job is the materials that the coil is made of. Different materials thrive better in different systems and environments, which affects the lifespan and efficiency of the coil. Making sure that your replacement coil is best suited for your unique system and location is integral to any facility, and failure to do so can increase costs and decrease reliability. Here is a breakdown of each material in your coil and what scenarios to select each in. 

Copper is the most common material in the tubing of the coil and offers many advantages for use. Copper is stronger and easier to maintain than aluminum and other materials. It has a better heat transfer rate and is much more reliable as a whole. When damaged, it is easier to repair, saving time and energy. Though it offers many pros, it is more expensive than other materials and is not immune to corrosion. In a system where reliability is required, such as chillers, schools, and hospitals, copper is your best option and will save much time and effort on the maintenance side.



Aluminum can be used in both the tubing and fins of the coil. More commonly found in the fins, aluminum comes with a lower cost than other options with more pliability. Aluminum is used in microchannel coil tubing and is much more difficult to clean, repair, and maintain than copper and other materials. In humid environments, Aluminum rapidly deteriorates, making it not the best choice for longevity near coastal environments and in southern areas. Aluminum's cheap and pliable nature makes it cost-efficient, yet be careful, as in the wrong environment it can be difficult to maintain. 

Stainless steel is the least common of the materials in a coil; however, it remains a viable option in very specific scenarios. Stainless steel is the most corrosion-resistant material of the three and is extremely durable. However, it is the most expensive material and comes with lower thermal conductivity than the other materials. In highly corrosive environments such as chemical plants and wastewater treatment plants, stainless steel tubing could be a solid choice for durability.


In addition to breaking down these 3 materials within custom replacement coils, it is worth noting that in certain environments, material alone isn’t enough to completely prevent corrosion and other failure types. In scenarios such as these, your best bet is to get your coils coated to fit the environment your system resides in. While more expensive, coatings can be the extra step your system needs to maintain efficiency and reliability.


At HeatEX Technologies, we offer custom coils that utilize these materials for each specific job, taking system and environment into account. This ensures reliability for your unique system and prevents unnecessary extra spending and time in the future. If your coil fails due to wrong material choices, call HeatEX Technologies, and our team will assist you with a more efficient replacement coil option.

Works Cited


“Four Facts to Know About HVAC/R Coil Corrosion: Copper versus Aluminum.” Copper Development Association Inc., 11 Sept. 2019, https://blog.copper.org/hvac/r/four-facts-to-know-about-coil-corrosion-copper-versus-aluminum. Accessed 27 July 2026.


“Using Copper and Aluminum for HVAC Coils.” Emergent Coils, 12 Jan. 2024, https://emergentcoils.com/blogs/news/using-copper-and-aluminum-for-hvac-coils. Accessed 27 July 2026.

What Actually Goes into Measuring a Coil

By Colby Maun • July 20, 2026
For any coil or heat exchanger replacement job, one of the first steps in the process is for HeatEX Technologies to measure the existing coil/heat exchanger to ensure a perfect fit in the unit. Recently, I had the privilege of going out to my second job site to take measurements with HeatEX Technologies. Here is my account of what actually goes into measuring a coil, and my experience from start to finish.

Trane CGAM070 Microchannel Conversion Case Study

July 13, 2026
After multiple refrigerant leaks sprang from a Trane CGAM070 air-cooled chiller in West Palm Beach, FL, our customer faced a difficult challenge. They had to decide whether to replace the failed microchannel condenser coils with new OEM microchannel coils or pivot and invest in a different, longer-term solution. After much evaluation, our customer decided to convert the chiller from aluminum microchannel coils to copper tube aluminum fin condenser coils.

The Biggest Takeaways from the 2026 ASHRAE Annual Conference for Commercial HVAC

By Colby Maun • July 6, 2026
Last week, from June 27 th to July 1 st , ASHRAE held its 2026 Annual Conference in Austin, TX, and brought together more than 2,233 HVAC professionals from all over the world. The conference covered a broad range of many topics prevalent in the industry today, from fundamentals and applications to AI in building design and construction. Here are some of the biggest takeaways from the 2026 ASHRAE Annual Conference for commercial HVAC.

5 Warning Signs Your Coil Needs Replacement

By Colby Maun • June 29, 2026
In a commercial HVAC unit, coil failure is one of the most frequent and costly problems a system can have. Coil failure in a commercial HVAC unit leads to performance, efficiency, and reliability issues, making it one of the most important aspects in the system. Coils can fail for many different reasons, and understanding when a coil is starting to need replacement can save facility managers tons of extra downtime and stress. Here are 5 warning signs that your commercial HVAC coil needs replacement, so that the next time your coil fails, you can be on top of the problem.

What Makes a Coil Custom?

By Colby Maun • June 22, 2026
What exactly makes a custom coil custom? Most facility managers assume that a custom coil only differs from OEM in sizing. The reality is that dimensions are only a fraction of what makes a custom coil custom. Each job is different, with many different factors going into a custom coil, such as dimensions, tube configuration, fin design, materials, and performance requirements. The most commonly thought of aspect when it comes to custom coils is the dimensions. This includes height, width, and depth of the coil, which allows for custom replacement coils to fit perfectly into the system they are designed for. Doing this without major modifications is crucial when manufacturing a custom replacement coil. The tube configuration of the coil also plays a very important role in customization. The circuitry, number of rows, and tube diameter all impact this aspect and contribute to the efficiency and heat transfer of a custom coil.

How Aging Infrastructure is Challenging Commercial Buildings

By Colby Maun • June 18, 2026
As a building gets older, it becomes much more likely to experience several different types of HVAC failure, which results in decreased efficiency and reliability in the system. Considering the fact that most commercial buildings in the US were built between 1970 and 2000, this aging infrastructure is becoming increasingly problematic in the world of HVAC. To increase difficulty, many organizations postponed renovation and retrofit projects during COVID and during times of economic uncertainty and inflation. Those decisions extended HVAC equipment beyond its initial design life in many cases, and now that it is finally time to renovate, there are significant challenges to doing so in those buildings. With today’s rising equipment costs, aging building stock, high energy costs, sustainability pressures, and limited budgets, many facility managers are burdened with attempting to keep their equipment running smoothly. As HVAC systems age, they experience coil degradation, efficiency losses, corrosion, and increased failures and downtime in general. Coils are usually one of the first parts to deteriorate, as they are exposed to plenty of different weathering aspects in the air, such as salt, moisture, and pollutants, to name a few. When a coil deteriorates, it reduces system capacity as a whole. Efficiency losses in older units are common as well, since with time, the unit has to work harder and harder to remain operating at the same capacity as it was when it was new. Reliability decreases for units due to increased unexpected failures and downtime, along with it becoming harder to source parts for repairs as technology advances and changes.

YCAV Air-Cooled Chiller Conversion Case Study

June 11, 2026
Location: Hotel – Fort Lauderdale, Florida  Overview: A 6-year-old York YCAV air-cooled chiller serving a hotel experienced premature condenser coil failure. Out of 10 total coils, 4 had already failed (40%), with the remaining coils showing active corrosion. The unit operates continuously, making reliability critical for guest comfort

HVAC's newest Refrigerants

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How AI is Reshaping the Future of HVAC

June 5, 2026
Increasing demand for AI, high performance computing, along with hyperscale data center expansion are creating a massive new market for HVAC. The shift is in cooling, as data center cooling is moving beyond incremental airflow optimization, and towards liquid cooling in order to support AI and its specific cooling needs. Because of this, the data center liquid cooling market is projected to expand from 6.6 billion dollars to 38.4 billion dollars by 2033. North America is the current hotspot for this investment as it hosts the largest concentration of AI training clusters globally. Historically, data centers have relied on air-based systems for their cooling, which includes CRAHs, chilled water systems, and precision cooling equipment. Because AI servers are now generating higher heat loads than previously (Modern AI racks can exceed 100 kW per rack compared to the traditional 5-15 kW loads of the past), facilities need heavier duty cooling, sparking the transition to liquid cooling solutions. This transition to liquid cooling is not removing HVAC systems and instead restructures their role within AI facilities. Removing building heat, maintaining environmental conditions, and supporting chilled water distribution systems are all issues that HVAC remains a critical solution to. As a result of this, specialized coils, such as the ones HeatEX produces are growing in demand along with cooling towers, heat exchangers, and other thermal regulation components necessary for dealing with high heat rejection requirements. This trend to support AI with Liquid cooling brings new challenges with infrastructure and compatibility for projects, as operators prioritize power usage effectiveness reduction and carbon footprint optimization. Ensuring coolant compatibility with diverse server architectures, leak prevention, and aligning cooling with rapidly advancing cycles are a few of these challenges. Operators are looking for companies that can specialize towards their plants and customize them to their need.

Condenser Coil Replacement Project

By Matt Lane • June 2, 2026
Renaissance Hotel @ Ft. Lauderdale