Congrats on the new appliances! It should just need an outside vent. The shorter and straighter the ductwork the better. A hood that size probably needs a very large duct - about 10 inch diameter round duct or similar. HOWEVER - building codes have changed in the past decade or so to factor in these oversized appliances. Large hoods draw a lot of air and suck the air down/backwards chimneys, furnace exhausts, etc, bringing carbon monoxide and other harmful gases back into the house. The code added that any hood over 400cfm must be connected to a make-up air duct that opens when the hood turns on and feeds air into the kitchen. Please consult a licensed mechanical contractor to install the hood and make up air system for your family's safety. I also highly recommend you have them get a permit and inspection to ensure proper work.

Does this hood have an internal blower?

(A) If not, I would recommend you purchase a 1000 CFM or greater nominal (zero static pressure) flow rate blower and decide whether to put it on an outside wall or on the roof, with a 10-inch duct between the hood and blower. The longer roof path may allow adding a silencer from Fantech. Selection will depend on house architecture and allocated cost.

(B) If supplied with blower, duct either path as described above without the external blower or silencer.

I am only guessing here, but suspect your existing wall vent will be too small for the blower you need to use so if you choose that direct option, some carpentry will be required.

Please dredge through the many hood threads here to gain insight into what your goals are and what the requirements are for good ventilation. Also note that a make-up air (MUA) system will be needed in most locations.

Thank you so much for the tips. I had no idea who to call to install - a licensed mechanical contractor. Bingo! Now to find one in my area...