Thanks Wilmer,
No such thing as too much information.
It will be all new electrical including the panel, I’ll follow along as it gets installed.
I love the idea of a hood, it would make the oven wall really nice and different from what we had.
However the hood was the contractors idea and with our small kitchen it might be best to go back to a built in vented to the outside.
Decisions, decisions.
Bruno - Don't skimp on the outside vent. Not negotiable in my opinion.
When you search specs on venting, many will be 399 cfm or lower. There is a reason for this.
At 400 cfm or more, building Code requires makeup air. This is air brought into the home so it can be exhausted by your hood/microwave (ie, it makes up and replaces the air the vent exhausted). Without it, in theory, the venting pulls a vacuum on the house, causing back drafting of other combustion appliances and fireplace if you have one. Back drafting can induce CO into the home which can be deadly.
With an older leaky home, you are likely not to notice lack of makeup air for hoods up to say 600 cfm, but your inspector will be asking for the makeup air system since you are 400 or more cfm.
Makeup air can be passive or active.
Passive is a hole in the wall with a screen on the wall cap (no flapper) which allows air into the home thru a motorized damper and filter box. The damper is energized with a pressure switch on the hood and opens to allow fresh air in. My opinion, these are marginal depending on the house. Small tight house (say 2500 sf or less), they are useless. Large tight house (say 7000-11000 sf), then they work. Small tight houses have less total air in leakage; large tight houses simply have much more SF and even with best practices leak enough. There are graphs showing that the hole required for passive makeup air becomes huge and I believe it.
My wife's kitchen has a roof mounted 1500 cfm blower with a 10" duct. She has an 8 burner Wolf gas range. We have foam insulated the home beyond what I do at the day job. The house is around 1900 sf on the main level (ranch) with unfinished buried basement. The 8" passive makeup air system is useless. If we turn the hood fan on, it will pull a vacuum on the house and back draft the wood stove with smoke pouring into the house from its air dampers. The door to the garage has spring loaded auto-close hinges since its a fire door; when the hood is running it won't let the door close as its sucking air from the leaky garage. The work around for now is we manually open a kitchen window when we run the hood.
Active makeup air systems use inlet fans to pull air into the home to match the rate of exhaustion. Meanwhile your conditioned air is being purged. So, they add resistance heaters for this. I am still noodling this retrofit out to automate things and elimate the manual window opening at our house.
In retrospect, I wish my wife had looked into an induction cooktop/ range. I tried but no luck. They have amazing performance rivaling gas, yet no combustion gases and no heat requiring venting. This in turn allows a much smaller more reasonable hood size for steam and grease fumes.
Lastly, our Wolf 1500 cfm hood is variable speed. But on low, its about 58% or 870 cfm which is still very large. Imagine your car only being able to go as slow as 58 mph with a top speed of 100 mph, the manufacturer knows this, and decides not to tell you. Pretty poor not to disclose the turndown on the cfm.
Wife's kitchen remodel has been a huge mindset rethink for me. None of these issues occur at the day job, but those houses are huge in comparison. Our house is somewhat unique being smaller, extremely tight with foam insulation, and overkill on appliances.
Sorry again for TMI, but maybe there are some nuggets here to help you with your project.