I would like to take a minute to review the important factors for correct and efficient chilled water coil operation. The first determining? Critical factor(s) of designing a chilled water coil is: a) the entering air temperature b) dry/wet bulb c) CFM d) GPM e) Required Btu's With that information it allows Nationwide Coils to duplicate or design a custom chilled water coil to meet our customers specifications. We are able to select the number of rows, fins per inch, and coil circuiting to select the correct Btu's for your chilled water coil project. Analyzing fluid pressure drop and fluid velocity... Fluid pressure drop and fluid velocity are specifications that are critical to the operation and longevity of water coils. The fluid pressure drop and fluid velocity are dictated through the coil circuiting of the chilled water coil. The less feeds going into your supply header will direct an increase in fluid pressure drop and fluid velocity. The sweet spot for fluid pressure drop (ft. of water) is between 5-20 and is the industry standard. Allowing pressure drop that exceeds 20 can pose numerous problems for your hydronic pump while allowing for a very high fluid velocity. Pressure Drop greater than 20... If you need a pressure drop greater than 20 for your chilled water coils, you must consult Nationwide Coils so that the proper pump may be installed for your chilled water coil application. Fluid Velocity... Fluid Velocity like fluid pressure drop is the byproduct of circuiting, the less feeds the higher the fluid velocity. Fluid velocity does not greatly affect your chilled water coil performance but does dictate the tube wall thickness of your copper tubing. For example a fluid velocity exceeding 4.0 will deteriorate .020" copper tube wall over years pitting the copper tubes from inside out. If you have any questions or would like to discuss more about the design of chilled water coils do not hesitate to contact us.