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Top Causes of Coil Failure

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Top Causes of Coil Failure

Why do water, steam and refrigerant coils fail?


Coil Plugging:

Poor or a lack of proper cleaning will result in a build up of dirt on the coil. This significantly impacts heat transfer, and increases the air pressure drop across the coil.


If the coils are installed near a moving piece of equipment (e.g. a fan) that is not properly isolated, the vibration can eventually cause leaks. This is because the tubesheet holes will eventually cut through the tubes.

Corrosive Environment:

Both in the air or inside the tubes, a corrosive substance will eventually eat through the coil and cause it to fail. This can be combated with heavier or more resilient materials (e.g. stainless steel or cupro-nickel), as well as coatings.

Freezing Temperatures:

Damper or freeze-stat failure can cause a coil to be subjected to below-freezing temperatures, which can cause the tubes to burst quickly if the coil is not drained properly. This is because ice build up in the tubes increases the pressure until the tube ruptures, typically at the u-bends.

When replacing a coil, partner up with a team who will walk you through the engineering and explain it along the way. Mainstream has decades of experience and we know how to make sure everything from the quote to the installation go smoothly. Send us a message to learn more!

What are EC Fans?

If you work within the HVAC industry, you have likely begun noticing many references to EC fans, or ECM fans.

What are they, and what does “EC” mean?


ECM stands for “electronically commutated motor”. EC motors are essentially DC brushless motors integrated with the electronics to run on an AC power supply. Converting, regulating and controlling the power all happen within the motor. Additionally, EC fans are always direct drive, with the impellers mounted directly to the motors. Why is this better than traditional AC motors?


EC motors are efficient:

DC motors are typically about 30% more efficient than AC motors. With EC technology, the benefits of this added efficiency can be reaped without requiring a DC power supply. EC motors are available to work with voltages ranging from 115V to 480V.

EC fans are easy to control:

The electronics in the motor act as a VFD, taking the power and throttling it to achieve the required fan speed. This means that there is no need for a VFD–it is replaced with a simple speed controller (note, Mainstream has different controllers available, but a speed controller is always included with our EC fan arrays). All the EC fan requires is power and a control signal.

EC fans require essentially zero maintenance:

EC fans will never require replacement belts, shafts, bearings to be greased, or any balancing. In the unlikely event of a fan failure, replacing the fan is as simple as removing four bolts and wiring. Replacement EC fans are available in stock, and are small enough and light enough that a replacement typically requires no more than two people for half an hour.


And much more…


There are a number of additional benefits to using EC fans; they are quieter, require less space, are extremely simple to install, etc. We highly recommend checking out Mainstream-corp.com/IntelliCUBE to learn more about Mainstream’s IntelliCUBE fan array system, or head over to our fan array product page to learn about other types of fan arrays.

As always, we welcome you to contact us (contact form below) or give us a call with any questions this article may not have answered!

EC Fan Arrays for AHUs

Does a fan array make more sense than a single fan? Is there any reason to upgrade to EC fans?

These may be questions you or your customers are facing when it comes time to retrofit an air handling unit with a new fan system. As technology develops at breakneck speed, how can you be sure you will be installing the best equipment, not only for efficiency, but also for dependability and operational simplicity going forward?

The answer is yes, fan arrays are nearly always the better option–for a number of reasons:

Redundancy and reliability

Having an fan array means the failure of a single fan will not mean a complete loss of airflow for your facility; in fact, in a well designed system it could mean zero loss, as n+1 redundancy can easily be included from the beginning of the engineering process. Backdraft dampers are nearly always included, which ensures that the air handling unit can continue operating without any human intervention. Additionally, with EC fans, the remaining fans can immediately be ramped up to compensate for any lost capacity (click here to learn more about EC fans).

Ease of installation

By engineering an array of fans instead of a single fan, the size of each fan and motor is greatly reduced. In fact here at Mainstream we have experience replacing fans upwards of 100 HP with arrays of fans with individual motors that are less than 10 HP each. Why? The significantly smaller fans are much easier to handle, making install much faster, easier, safer and cheaper. In fact, we typically supply the fans mounted in cubes that can be stacked and bolted together extremely quickly–learn more at mainstream-corp.com/IntelliCUBE.

Quiet Operation

The innovative and extremely well engineered design of EC fans means they are inherently quieter than most AC fans. This is especially true when the fans and motors are reduced to fit into an array. Sound can be further reduced by lining the cube interiors with acoustic insulation, or simply reducing the fan speed, in the unlikely event sound is an issue.

And much more…

As discussed in the earlier “What are ECĀ Fans?” article, there are additional benefits to EC fans, including ease of control and efficiency. We can confidently assert that the benefits of EC fan arrays strongly outweigh any potential negatives, and are undoubtedly the future of the industry. If you are interested in learning more about the fan systems Mainstream has to offer, head over to Products > Fan Arrays, or give us a call!