Does the fins density impact the working performance of inter cooler ?

The structure of the inter cooler is fins and tubes of most centrifugal air compressor models, for example the IHI, Elliott, Cooper Cameron, Samsung, etc. The fins stacked and expanded tightly on the tubes to have the full contact, so that the heat of the hot air could be transferred by the cooling water in the tubes.

The specification of the fins density is called FPI, abbr of fins per inch, which means the quantity of fins in the length of one inch, e.g. 17 FPI means there’re 17 pieces of fins in 25.4 mm, and the fins spacing is 25.4/17=1.494 mm.

Fins per inch

FPI=fins quantity per inch

The fins density contributes a lot to the cost of the inter cooler. The more fins the cooler has, the higher the price is. Some drawings given by customer have marked the fins density, but most times there’s no clear requirement, and the suppliers won’t tell you unless they are asked. So if you think the inter cooler price is too high or suspect why the price is so cheap, well you may ask the fin density of cooler.

fins density on drawing

Some drawings have clear requirement of fins density

Does the density of the fins impact the cooling effect and how it works?

Theoretically, more fins, better cooling effect. More fins have more contact and heat transfer area at the same cooling water in the tubes. Meanwhile, more fins create higher resistance, the space between fins is smaller and it is more difficult for the air flow to cross the cooler, the pressure drop would be bigger.

inter cooler fins density

Some original inter coolers has quite small fins density

Actually, the design of the inter cooler has enough design allowance, and the density is quite small even for original inter cooler. From our measurement experience, the original inter coolers fins density is between 15 to 19 FPI. Also, the fins mould could not have that high fins density; sometimes you can’t have the wanted FPI.

So don’t care too much about the fins quantity of the inter cooler, it only matters when calculate the material cost. Article of IGcooler, all rights reserved.