Proper NACA intake design.

[JoeMartin]

I see a lot of Sonerais with the NACA intakes for cabin cooling. I'm not saying they did it right or wrong but found this article on proper design of the NACA intake.
Sportplane Builder Naca intake

If you are really bored or interested in the subject here is NASA's declassified 1945 report on it.
NASA's NACA intake report

 

[subnoize1]

The best thing is this is one area where you can 3D print it. Of course most printable plastics have high weight (especially PETg, friggin stuff is lead) so I personally would print a mold for fiberglass or carbon fiber instead. Even a 3D printed mold for hydro-forming is possible using ABS or PETg with high in-fill (70% or higher).

If you can't design your own in CAD you can do a search for "NACA Duct 3d model" and download it. Some of them that are available even have sliding shutters or come out to round connector for tubes. Be warned that the coolest of them are paid downloads. But they are advanced designs and once you own it you can print as many as you need.

I might come up with a ready printed NACA duct if there is a common size and design you guys want.

Of course there is a pre-made one at Aircraft Spruce; https://www.aircraftspruce.com/catalog/appages/nacascoop.php?clickkey=3699