Marlo Coil Quality Stands Above the Rest: Part 1

At Marlo, we know there are other choices out there for replacement heating and cooling coils. But other manufacturers simply don’t offer the level of quality you get with Marlo. So for anyone comparing prices on any type of commercial or industrial fluid coil, steam coil, refrigerant coil or specialty coil – including process heating and process cooling coils – be sure to look at more than just the price.

We truly believe our commitment to quality is second to none. And we’re happy to tell you why. Read on for a list of some of the many ways we build extra durability and reliability into every coil we produce. If you ever consider a replacement coil from another manufacturer, compare these quality features when you compare price, and we think you’ll see the value you get with Marlo far outweighs any minor cost savings. This article is the first of a two-part series on Marlo quality. Check back for Part 2 to learn more about what sets Marlo apart.

Heavier tube wall thickness

At Marlo, we use copper tubing with .025” thick walls as standard, and can go as high as .065” for heavy duty applications. Many of our competitors’ coils, however, use just .020” thick wall tubing. That means even our thinnest tubes are still 25% thicker than others. Needless to say, our much thicker tubes are obviously significantly more durable and much less resistant to the effects of corrosion, resulting in longer coil life.

Superior fin construction

When it comes to fins, we also go the extra mile to assure both greater durability and increased coil performance. We typically use .010” thick aluminum for our fins, which is 33% thicker than the .0075” material used by many other manufacturers. We can also go as thick as .020” for heavy duty applications. Our thicker fins are much more durable, which is especially important in applications where coils are washed down, because .0075” and thinner fins can bend easily during coil cleaning. In addition, thicker fins also improve the heat transfer capabilities of the coil.

Another added quality feature of Marlo fins is their extruded holes, which are formed by a die that raises a collar around the hole. This very precise raised collar is used to set fin spacing, ensuring that the coil has the specified number of fins per inch, which guarantees the performance and air pressure drop predicted by our MarloMetrics coil selection software. 

Our fin dies are routinely maintained so the tolerance of the hole size and location are extremely precise, assuring that the tubes will insert uniformly through the holes to allow a strong bond during hydrostatic expansion into the fins, resulting in maximum heat transfer and the highest possible performance of the coil.  

Extruded tube sheets

Tube sheets on each side of the coil, and in the center on larger coils, support the weight of the tubes and add stability. At Marlo, we precisely extrude our tube sheets, which produces a wider and smoother surface area for the tubes to rest on. This reduces wear on the tubes from thermal expansion and/or vibration, provides additional support for the tubes, and ensures long coil life.  

Ferules in tube sheets

One of the options available with Marlo coils, which many coil manufacturers do not provide, is the addition of copper ferules. These copper rings are inserted into the holes in our tube sheets, if requested, to provide an additional layer of support for the tubes. This is a similar strategy to using extruded holes in the tube sheets, but the use of ferules takes coil strength and stability to the next level, maximizing durability – especially in environments where large thermal gradiants or vibration may be encountered.

Welded box headers

All coil box headers at Marlo are fully welded by experienced craftsmen. Our welders are certified annually and must meet very stringent requirements. They use only the highest quality materials and welding processes in the construction of every Marlo coil, resulting in long-term durability and reliability.

The quality features mentioned above are some of the many reasons why Marlo can proudly offer the best warranty in the industry on every coil we produce – a full three years. This compares to many other coil manufacturers that only offer warranties of one year or less. 

When you add up all the extra quality features – and the industry’s best warranty – it’s easy to see that you get more for your money with Marlo. We may not always offer the lowest price, but we feel confident that we’ll always offer the best value.

If you want even more great reasons why you should choose Marlo heating and cooling coils for your commercial and industrial applications, watch for Part 2 of this article, which is coming soon. We’ll discuss our use of hairpin bends, our superior casing construction, our durable headers and connection stubs, comprehensive leak testing, and more.