Need a little AA help

[Triticum Agricolam]

Ok thanks for the replies. Still leaves me wondering if there's any downside to making a perfect square port? Would it be more efficient and worth it for me to do the extra work?

The downside of the square port is its more complex to build and will take up more internal box space since it takes more panels to make.

As far as efficiency goes there are equations for comparing different aspect ratio ports for their air flow efficiency. Round ports are the most efficient so the equation I use compares rectangular ports to an equivalent area round port. Your port is 51.625 sq. in. A square port of that area would be equivalent to a round port of 48 sq. in. A 3.5" x 14.75" port would be equivalent to a 43 sq. in. round port. So there is about a 12% difference in equivalent area.

The big question is does that difference matter? In my opinion that depends on how high your port velocities are going to be. Since yours should be well under 30 m/sec I don't think the port shape will make any perceptible difference. You could always make the full height port 12% larger to compensate if you were worried about it.

[afrakes]

Thank u very much for the explanation. I will have to think on it and make a decision based in all your help.