Long time reader, first time poster.

Thanks so much for all of the insightful discussions and everyone sharing their experiences with kitchen appliances etc.

I have a question that seems like it would be easy to answer, but neither my cabinet people nor several range providers seem to be able to answer...

I am setting up my range vent with a Fantech in-line blower (FKD8XL) and silencer. I know I need to get a "liner", but all of the pictures I have seen of these seem to be just the "insert" - filter, lights, rheostat, mounting into the hood.

Now, the hood is a slant top, and I was expecting for best laminar flow, that the hood itself would be lined with SS or aluminum and that the insert would connect to that - i.e. that immediately above the liner the vented area would gradually get narrower as it goes up to the duct piping. Like a pyramid.

But the pictures I see, such as this one:

http://www.fantech.net/accessories5_02.jpg

seem to show the duct connected immediately behind the insert. This seems like it would work great for just the center of the filter, but very poorly at the edges. Do hoods shaped in this manner exist? Or are they all just flat as a pancake immediately behind the insert?

Finally, any recommendations for the insert? Seems like most would function exactly the same, and that one could shop for cost. The sound and power of the blower itself seems to be the main differentiator. (I've been thinking filters rather than baffles, but could be convinced)

Any advise is appreciated!

Brad