In either case do not vent into the wall or the attic.
Vent range hood through attic.
Vent your bath and kitchen exhaust fans through the roof through a special roof hood.
Ducted or vented range hoods send air outside through a duct.
First remember that there is a lot of grease and moisture in that exhaust just think of how dirty that filter gets.
The procedure is similar to the installation of the kitchen hood vent through the roof but it is slightly different though.
Many times your choice depends on where your range is located.
Vent away cooking odors and filter out heat smoke grease and moisture.
Vern has a range hood on an inside wall and is wondering if he could just use the hollow wall cavity or should he line it and could he just vent into the attic because the attic itself is vented.
There are actually a lot of interesting questions there vern.
Venting through a roof vent or exhausting them in the attic could cause moisture problems and rot.
It is definitely not a good idea to vent a range hood into the attic.
Installing a range hood vent through an outside wall.
So if you vent.
If it sits on an inside wall venting through the attic and out is a better option but if it is on an outside wall it is more practical to vent through the wall.
Ideally the range hood should be vented to the outside usually through the roof.