Nationwide Coils’ response to COVID-19: Our customers and our employees are our first priority.

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

Understanding coil model numbers might be part of the job, but it shouldn’t be such work. Here we de-code Carrier Chilled Water Coil model 28CW which is model 28CW1620DA1112---K.

Coil Duty2 28 CW

This chilled water coil model is primarily seen in Carrier 39EB and 39ED air handlers. The model number tells you everything you need to know in order to quote the coil. With that, let’s de-code:

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

The “28CW” indicates that we are looking at a chilled water coil.

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

"1" means a steel connection. A 2 would mean it is brass, but that’s not common.

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

This digit indicates the number of rows in this type of Carrier Chilled Water Coil, which can be 4, 6, 8 or 10 rows. So, in this model, there are "6" rows.

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

The next two digits, “20”, tell us the number of tubes in the face of the coil, indicating the finned height of the coil.

Carrier usually uses ½" tubes for their chilled water coils. The range number can be 12 to 44, increasing by increments of two. So, for this model number, our chilled water coil has 20 tubes in the face, which tells us that the finned height of the coil is 25" tall. We have seen Carrier coils with 5/8" tubes, so you should always double check and measure the finned height of the chilled water coil.

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

The circuiting that Carrier offers for this type of chilled water coil is Q, H, F or D, standing respectively for quarter, half, full or double. This model shows a “D” which indicates double. To check this, make sure your coil has 40 tubes (double the finned height) feeding into the supply and return header respectively.

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

The “A” tells us three important characteristics of the chilled water coil: fin material, casing material and how many fins per inch. The fin options are aluminum and copper. The casing options are galvanized and stainless steel, and the fins per inch range from 8 to 14. The “A” means aluminum fins at 8 fins per inch. There should always be a letter in this digit, which could be A, B, K or L and they all mean something different as shown below.

A = Aluminum / 8 FPI | B = Aluminum / 14 FPI

K = Copper / 8 FPI | L = Copper / 14 FPI

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

Next, we have an “1” which tells us the coil has .016 copper tube wall thickness. If it were a 2, it would mean the tubes are thicker. There can be standard copper wall or thicker copper wall, if necessary.

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

The next 3 digits, “112,” tell us the finned length. In this model it is represented in inches, so it’s 112 inches. Careful, some models are shown in centimeters and you would have to convert to inches.

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

And finally, the “K”. One of the great mysteries of the world. Yes, no one really knows what the K stands for. Kite? Knish? Kazoo? Kould be anything, so we take it as a cue to just double check all your measurements on site!

There are literally hundreds of different combinations that make up a Carrier Chilled Water coils. Have a question or need to decode a coil model number? Let the professionals at Nationwide Coils make your job easier. Our reps would be happy to help!

The Nationwide Coils Blog is a commercial HVAC blog written by industry HVAC experts with almost two decades of industry experience. We offer invaluable insights into commercial HVAC products and services and invite you to email us anytime.