Are there industry standards for water coil circuits?

As I mentioned in my last blog, circuits are related to the number of tubes in a coil being fed from the header. There are some industry standard patterns. For example, a full circuit = 24 tubes. A double circuit = 48 tubes. Most chilled water coils and hot water coils have the supply and return connection on the same end of the coil.

In addition to selecting the appropriate number of circuits to control the speed, which in turn controls heat transfer in the coil, there are other considerations.

In selecting the number of circuits, you need to consider the number of rows in the coil. For example, if there are 12 tubes per row and the coil is 8 rows deep, you have 96 total tubes. The diameter of the tubes allows you to calculate gallons per minute (GPM). Based on a total of 96 tubes, there are several circuit options, depending on your preferred GPM:

Feed                # Passes

12 tubes          8

16 tubes          6

24 tubes          4         

Let Emergent Coils help you decide the most efficient number of circuits for your hot water or chilled water coils. Simply give us a call at 1-855-Coil-Now.