Coil of Duty: Reading a Carrier® Chilled Water Coil model 28CW.

The Carrier 28CW chilled water coil is commonly found in models like the 39EB and 39ED air handlers. These coils are essential for cooling air in HVAC systems, and understanding their model numbers can save time when ordering or replacing parts. Let’s go through the model number step by step:

28CW-1-6-20-D-A-1-112-K

28CW – This indicates that it's a chilled water coil. The “28” refers to the series, while “CW” stands for Chilled Water.

1 – This digit represents the type of connection. A “1” means steel connection, while a “2” would indicate brass (which is less common).

6 – This tells us the number of rows in the coil. Common options are 4, 6, 8, or 10 rows. In this case, there are 6 rows.

20 – This number corresponds to the number of tubes in the face of the coil. For standard ½” tubes, this also helps determine the finned height. In this example, 20 tubes mean the coil is approximately 25” tall. Always verify with actual measurements, as some coils may use 5/8” tubes.

D – This letter denotes the circuiting type. D stands for “double,” meaning the coil has double the number of tubes in each header. So, a “D” would imply 40 tubes total (20 per header).

A – This character provides information about the fin material, casing, and fins per inch (FPI). Here, “A” stands for aluminum fins at 8 FPI. Other options include B (aluminum at 14 FPI), K (copper at 8 FPI), and L (copper at 14 FPI).

1 – This number indicates the tube wall thickness. A “1” means the tubes are made of .016” copper, which is standard. A “2” would mean a thicker wall if required.

112 – This is the finned length of the coil, measured in inches. In this case, it’s 112 inches long. Be sure to check whether the measurement is in inches or centimeters, as conversions may be necessary.

K – This one is a bit of a mystery. No official documentation confirms what the “K” stands for. Some speculate it could be a batch code, a location identifier, or just a placeholder. Either way, it’s always best to verify all dimensions on-site before making any decisions.

There are countless variations of Carrier chilled water coils, each with its own unique combination of features. If you're ever unsure about a model number or need help identifying a coil, don't hesitate to reach out to HVAC professionals who can guide you through the process. At Nationwide Coils, our team has over two decades of experience and is here to help simplify your next project.

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