You don't need a roofer if they vent goes out through the wall. That said, the first difficulty is where you can or cannot hang the hood as the joists in the ceiling may be in the way and you have to offset from your desired location. You can open up the ceiling in the space where the duct will run and see if there is wiring and plumbing that gets in the way. You can do as much as you feel competent enough to do. Let me say that refinishing flat drywall is a PITA.

kaseki, Thank you for your input. I have lived in this house since 1981 and not ever had any insert/fan/liner, etc. I cook quite a bit but not a lot of greasy stuff. I am mostly vegan and so there is a lot of stir fry type of cooking. I also bake quite a bit which is one reason I want the dual fuel. One question regarding your suggestion--If I were to center the insert over the range and put stainless steel over the other part, would that present a problem for the duct since the duct is centered in the "boxy hood thing"? By this I mean that the hole where the duct goes up to the roof is at the center of the box so if the insert were to be centered over the stove, the mouth of the insert that fits into the duct would not line up with the hole. I hope this is clear. Is there a way to connect the liner to the ducting by possibly doing some type of elbow connection? I have really no idea, I am just thinking about it visually. One other thing I had thought of is that the boxy thing is pretty high (about 37.5 inches above the counter). Would it look odd to build on it a little by either adding some trim or molding around the edge to extend it down a little more? Another option would be to get a regular hood of some type that might work with the box. Not sure what that would be, maybe a standard low profile vent a hood or perhaps some type of wall type hood with a long neck that comes down and flairs out below the box over the stove--it could look good or it could look really weird. I understand what you say about losing all or part of the boxy thing. But this house is very old and I have literally resurfaced every bit of it over the years. You can't do anything without opening up a huge can of worms. I am already spending quite a bit to redo my electrical panel and have a 240 outlet put in so it isn't really in the budget to rip it out. Being a perfectionist at heart, it is tough though for me to be okay with good enough, but I think on this one it will have to do. I suppose we could always close up the bottom of the box except for the access to the duct and just attach a lower profile hood to the bottom of the box (likely centered over the stove).

Unless you already have make-up air from the previous ventilated hood installation, I'd go for 390 cfm (cubic feet per minute), which is below the limit for MU air safety code requirement in most areas--but check with your local code. Since you have an electric range, and it appears to be venting directly to the exterior, that should be sufficient. If you post the questions to the Appliance forum, there a several very helpful posters who can answer specifics.

"Thank you, Kaseki! I’ve been reading your past posts-would you mind sharing again what cooking device/range hood/ makeup air system you chose and why?" You may find images of elements of my kitchen in various posts. I won't repeat them here. Also, some hood flow parameters may be found in FAQ I. Please note that my kitchen reno planning began in 2007, with most purchases of appliances made at the end of that year. Delivery was taken significantly later for most items, but well in time to confirm measurements and interface details. Explaining rationale would make this tediously long, take too much of my time, and jack this thread. I owe a kitchen photo to the FAQ II thread, and one or more should appear in the fullness of time. The cooktop: I have two induction cooktops, a 36-inch Frigidaire Gallery (replacing a 36-inch Electrolux clone Kenmore that failed after 5 years or so) and a Cooktek 3500W induction wok. These are set in soapstone over cabinets in which there is added stone support and wire racks for pans, providing maximum air volume for cooling. The hood system: Overspreading these is Wolf's largest Pro Island hood set at 34.5 inches above the counter. The hood connects to a damper, then a Fantech silencer, and then a Wolf (Broan) 1500 CFM roof blower (which has a damper). (As I have explained many times, once installed in a hood system blowers cannot flow their rated CFM due to pressure losses. I have measured, however, about 1000 CFM with presently passive MUA and no other household exhaust blowers operating.) Duct is 10-inch. The secondary hood system: There is a secondary system comprising a pair of ceiling registers (14 x 20 if I recall), 3M Filtrite filters in the register boxes, a damper, silencer, and roof mounted NuTone down-blast blower. I believe this blower is rated 600 CFM, but can't find my literature for it as it was originally bought to provide additional flow for a '70s cooking center with miniscule blower performance. The registers are ceiling mounted over a pair of Wolf wall ovens. The MUA: I have planned an active MUA system, but all parts have not yet been acquired. There seems to be no end to new "required" projects. The system as it presently exists is operated passive, and comprises a highly ventilated attic with an additional roof-mounted down-blast commercial blower housing for eventual ducted air intake, a one-inch pleat 24 x 24 furnace filter (to be replaced with a lower pressure loss 4-inch pleated canister version, a 30 x 30 heat exchanger connected to my oil-fired hydronic heating system, and a 36 x 36 diffuser at the end of a hall that connects to the kitchen. The control system for this is intended to keep the kitchen pressure equal to the outdoor pressure (which will be the attic pressure once the MUA is ducted). Some elements of this are place. A Fuji computer module in a DIN control array next to my furnace will attempt to adjust its natural frequencies (poles and zeros) such as to make a stable MUA system independent of the main hood flow rate, the wall oven vent flow rate, and bathroom blower flow rates. The differential pressure sensor upstream and motor downstream control loops are 20 mA current type. Separate sensors and controls are used to keep the heat exchanger from freezing when not in use and otherwise keeping the air passing it temperate. Blower will be the largest that can get into the attic that Fantech sells that incorporates the 10 Vdc control voltage motor. (I forget the part number.) This wasn't available back ca. 2010, nor did Fantech list a motor controller that could handle that size motor back then. If starting from scratch, I would investigate the present offerings of Electro and Fantech to minimize my work, but large flow rate in an assembled unit would likely not fit into the attic without removing the diffuser and heat exchanger for a one-time installation. While balanced air pressure is highly desirable for several reasons repeated often on this forum, I should note that my System 2000 oil furnace has its own MUA and a sealed exhaust stack installed within the original brick chimney that served the previous one- and two-generations-back Beckett boilers. The hot water storage is heated via a hydronic loop on the furnace, and the dryer is electric. Hence, back-drafting of combustion appliances is not an issue. To deal with the flow to the MUA heat exchanger (capable of 120k BTUh if necessary) as well as the longer reaches of my house hydronic plumbing, I use a larger (higher head vs. flow rate) Taco pump than is usual.