Why aren't you buying an insert such as this 22"-deep Trade-Wind VSL400 Series 42 Inch Wide Range Hood Insert that fits the hood you plan to build?

I think this Trade wind could work as well, thanks! It looks very similar to the one Fantech is selling, both have a spacer in the middle with non continuous baffles. I think Prestige is off the list now.

I have a quote on the Modern Aire PSBL, but it is around $1500, but has continuous baffles and is known for excellent design.

Thanks Kaseki, I was looking at those, but I think the overall height of the box at 12" is going to be an issue with ducting.

The Modern Aire seems to have a much better baffle design than the Tradewinds and Fantech but at twice the costs. I think I'm willing to pay that if the quality and performace is there.

Fantech HL42 with decreased baffles since they seem to be using the same size baffle inserts in all their models.

Are you going out through a wall next to the hood?

I need to go straight up with a jog half the width of the hood, then it goes straight up through one floor into the attic. This is why I need lower profile, to accommodate the jog.

ModernAire can build almost anything you want that makes functional sense. In this case instead of a trapezoidal sectional area, the sheet metal front and back could be made so that the back was vertical and the front more sloped, thereby offsetting the duct port at the top toward the rear. In fact, I believe the Wolf liner is offset that way. I don't know the exact positioning of the duct port. Are you 'jogging' into the wall cavity?

The duct has to go up through the ceiling in the front left corner. I probably should've just posted this picture from the beginning :). If the opening could be in the front of the insert, that would make things much better from a jog and planning perspective for sure. I have two 90 degree bends here just to make sure it will work, but I would probably use the adjustable bend ducts and not have these two sharp 90s.

This is the Fantech HL42 with a 10" out. The Modern Aire is 22", and if I could put the out duct on the front side or even front left, that would be great, not sure thought with air flows how well that would work vs directly in the center.

ModernAire can likely build an upper shell with the duct interface where you need it. Is your duct diameter in your model the correct one for the candidate insert? A deeper insert would be more likely to fit an 8 or 10-inch port in the desired location, given an in-line or roof blower.

I will have to contact Modern Aire and see what my choices are for duct placement on their 22" insert which is 6" tall. If the shell is slightly taller but I can move the duct to a different location, that would probably also work. Ceilings are only 94" or so unfortunately.

I am planning on a roof mount 1000cfm fan like the Abbaka which uses an 8" duct and is the size duct I want to use through the ceiling and into the attic.

A standardized duct opening in an off-the-shelf insert could be matched with a plenum over it having an offset port. This configuration would likely work with minimal inches of pressure loss. (There may be some slight added noise over that from two duct bends.)

Do you have room in the attic for the 8-inch Fantech silencer?