Range hoods do not normally cone with parts for venting since they are application specific.

It sounds like you have a smaller hood with a vent deigned to allow use in regular 2x4 walls.

As long as there is not a stud in the way you should be able to go straight back and out.
The section of vent line and the exterior piece are available from any number of HVAC sources (but not always a big box store).

Happily the studs are about 6.5" to the left of center and 9.5" to the right, so the 10" wide duct should fit without any stud removal. It is a 2x4 stud wall with plywood sheathing and clapboard siding.

So it seems all I may need to add is a length of 3.25" x 10" duct (about 5" long) and a hood, with whatever is used to interconnect them.. sheet metal screws? It would be a problem is I had to construct the duct out of sheet material.

"It would be a problem is I had to construct the duct out of sheet material."

You buy a longer piece of standard duct and cut it down.

pop rivets that match the material of the duct are better.

Put aluminum foil duct ta on the seams after everything is joined.

Thanks, I stopped by Home Depot and found they carry an aluminum duct assemble with a spring door and hood for the outside. It has a through the wall 3.25" X 10" channel that is 5.25 inches long (should reach through the 3.5" stud depth, 1/2" dry wall and 3/4" sheathing, and have 1/2" to stick into the hood area... should work.

I'll look for aluminum foil duct tap to seal the joints.
Thanks.

"should reach through the 3.5" stud depth, 1/2" dry wall and 3/4" sheathing, and have 1/2" to stick into the hood area... should work."

That is cutting things rather close until you have opened the wall.

Right, and I haven't yet seen the hood, but if it is like the one I have, which is not vented, it attaches to the overhead cabinet and is butted against the interior drywall. From what I see of this unit, which is a similar unit, the subject vent assembly should stick into the fan chamber - I guess the only concern is getting a seal to assure the air moves outside, not into the wall cavity. May be the place for the aluminum tape you mention.

The new unit can be either vented or not and requires blocking the air path back into the house with a provided covers, otherwise it is just a air box which will vent out the wall, up through the ceiling, or back into the room, depending on which path is provided. I understand the "air box" has knockouts (3.25x10 through the wall and 8 inch round I recall for out the top/ceiling) and a path back into the room that has to be blocked.

It would be smart to consider the quality of the damper. If you get a poor one, it can either excessively restrict the air flow or be a rather large and constant area for uncontrolled outdoor air infiltration.

Thanks, the Home Depot unit has a large flange (flashing) about 2" wide and a good looking spring door. In real cold weather I'd stuff something in the outside just as I do with the cloths dryer and tell my wife not to use unless we remove the block.

I have never cut through an exterior wall but believe all there is, is the drywall on the inside, insulation between studs with the vapor barrier against the drywall (inside) and plywood sheathing with tar paper or other wrap on the outside, plus the clapboard siding. I believe it would be correct to remove enough siding to open the sheathing for the rectangular hole. Then to place the aluminum assembly through the hold with the flashing caulked (with an adhesive silicone caulk) around the hole under the assembly flashing. Then reinstall the siding to fit the assembly sticking though, with most of the flashing covered by the siding. Sound right?