Unfortunately we cannot vent through the roof. That would be the best choice but not possible due to cooktop location and the room above it.

It would be better than ductless.

That was my thought weedmeister. I had been going crazy with the thought of having to use ductless, having read so many negative things and knowing too that they simply don't do what needs to be done.

Sorry for the unintentional shouting - I hate when people do that! For some unknown reason was thinking the "title" should be capitalized. Tried to edit but it wouldn't let me. Ugh...

Ignoring the lack of parameters here to evaluate the system as a system, if the duct sectional area is a bit cramped, as this one might be, use an external blower with a higher CFM rating as it should compensate for duct pressure loss. If using an internal blower, then living with a bit more noise with a higher flow rate internal blower should be considered.

Where the duct takes a bend to pass through the crawl space, I suggest an inspection/clean-out capability be included. This could just be an easy way to temporarily remove the bend.

Thanks kaseki - that idea of clean out in the crawl makes sense. I am going to get another opinion as well to be sure this is the only option, and if so, is it the best way to go about it. Appreciate everyone taking the time to answer!

Provided the hood is above the range (not a the back or, even worse, downdraft), ANYTHING is better than ductless! How many CFM is your proposed hood (450? 600? 900? 1200?)

Oh no, in the same way I noted ductless doesn’t work, I know that downdraft doesn’t either! It will be above the cooktop and CFM is to be 600. Thanks for the input, sktn77a.