Plate Finned Coil Heat Exchangers

Plate Finned Coil Heat Exchangers

The tubes in a plate fin heat exchanger move through a series of metallic "fins." To make these fins, a continuous roll of metal, such copper or aluminum, is sent through a press that trims the sheet to size and punches holes for tubes. Presses use a range of dies to achieve this, enabling different combinations of tube diameter, tube to tube spacing, and fins per inch (FPI).

Tubes are then inserted through the fins. In order to enhance heat transfer between the tubes and fins, the tubes are then inflated to create a tight bond inside the fin pack. Either mechanical means or water under pressure can do this.

Benefits

A large range of materials can be used to construct the fins in plate fin coils. Notable examples include copper, aluminum, carbon steel, and stainless steel; copper-nickel materials are less prevalent but nevertheless exist.

Fin surface layout options: Among other things, fins can be upgraded and altered in a variety of ways to improve air turbulence or make cleaning the coil easier. Typical fin surfaces include:

Flat Fin

Corrugated Fin

Sine wave Fin

Raised lance Fin

Louvered Fin

Because plate fin coils have a larger secondary surface area than spiral wrapped fins, energy is transferred through the coil more effectively, perhaps resulting in a higher heat transfer coefficient on the air side.

Variation in fin density: A broad variety of fin densities, usually between 1 and 25 FPI, are possible with the design of plate fin heat exchangers. While spiral-wrapped fins with very low fin heights can reach significantly greater FPI, coils with regular spiral-wrapped fins are more constrained in this area, typically ranging from 4 to 13 FPI.