We have a Zephyr Hurricane. It's fine. Not as great as the VentAHood we had previously, but it was a fraction of the cost. What do you cook? Frying, wok cooking? Or boiling pasta noodles every now and then? If you're creating a lot of demand on a hood, then pay for a VentAHood. If not, with it ducted to outdoors, the Zephyr is probably sufficient. Really depends on how you cook.

Cooking runs the gamut, but quite a bit of frying, pan searing, bacon, some wok (hoping to get into this more with a gas range!). If I could swing it, I'd have a 48" open burner range with a 1500CFM hood running 10" ducting with MUA. We like to cook, a lot, and try out new things. I don't like being limited by my implements (who does) but understand we're currently dealing with some constraints. Next house will be the "no-holds-barred" kitchen...

Yeah, we did that in the last house - Blue Star with VentAHood. SO expensive, and even though we sold the house for a good bit more than we paid, we didn't get that money back. Ended up buying a house with constraints so we're making do. Live and learn. Retirement is on the horizon and I'd rather have fun than spend on another fancy kitchen. Priorities.

Fair enough, can't blame you there! I've always loved to cook but have been constrained (financially and appliance-wise) until this point in my life. So I'm looking forward to at least having a gas range and a hood that can handle pan-searing a steak without setting off our smoke alarm.

No air is removed by the hood that didn't get to the kitchen (make-up air). So just because you can escape code enforcement below 600 CFM doesn't mean that you will actually be able to draw 600 CFM with a 600 CFM rated blower. Most likely, 400 CFM would be your limit, and that only with a low resistance source of MUA. So some thought about how leaky your house is, how you might improve the leakiness on demand, and where to take the MUA and where to release the MUA should be part of your plan.

Search and read the myriad MUA related topics on this forum. Read the hood topics to see what CFM you should provide capability for.

Thanks Kaseki - I'm all for doing things properly. When I researched MUA I basically came to two conclusions: a proper MUA installation is prohibitively expensive (I'm in Raleigh, NC for what it's worth in terms of conditioning the air) and most people circumvent the need by opening a window or two when highest setting is being used. I'm not saying that's the proper way to address the situation, it just seems that a lot of people A) research MUA B) find it's illogical for their situation for one reason or another C) opt to just "open a window".

If there's something I'm missing, such as a relatively inexpensive way to install makeup air, a DIY solution, etc. I'm all ears. The research I did do went a bit over my head in some regards and, again, seemed to lead me to the conclusion that most people (rightly or not) skip MUA.

Where code allows, and cook's situational awareness is sufficient, then open windows will provide MUA. There is still some resistance passing air through typical window screens, so expect some degradation in blower performance. Dominant pressure loss will be the baffles if the windows are open enough, so flow rate likely will be near the 2/3 of the blower rating rule of thumb. Some thermal underwear is advised for the coldest days if cooking very effluent prone food at high hood power.

It is also possible to put a duct with a weighted damper into a room from outside. Or this plus a furnace filter. Or any of these plus an extra room heater that operates on the room's air temperature. This avoids complex interactions with the blower and/or kitchen pressure measurement.

Thanks kaseki - at this point I'm still thinking a 600CFM blower due mainly to my 6" ducting. I'd love to replace with 8", but I feel like that's maybe getting a bit too involved when the alternative is simply swapping out the OTR microwave for a hood.

Still stuck on Zephyr/Kobe/Z-Line...I'm thinking I just need to make a decision and jump.

FWIW, this is a thin dish cloth being sucked up by our Zephyr Hurricane. It'll suck! LOL

I had to disassemble it when the roofers dropped crap down the vent pipe into the blades. Easy peasy. Works great again!

I can only help with requirements; for aesthetics you are on your own (plus spouse, where applicable).

So....just so I can chew on it; what's generally involved in changing out the ducting to the exterior wall? Ducting goes up through a cabinet, up through a small soffit, and then 90s out an exterior wall. Maybe...5-6' of ducting from what I can tell?

We're not keeping much in the cabinet...could remove cabinet and go with a wall-mount hood. Probably need to extend backsplash a bit, do something about the remaining soffit(not sure what?), repurpose top moulding from removed cabinet to finish runs to the wall on existing side cabinets...that's probably about it. I'm fairly handy with DIY stuff so it doesn't sound too crazy. Wall-mount hood would look nice.

Round and round I go like usual. Off to Google to see if I can find a blog post of someone who's done similar.

Does anyone have any advice/guidance on removing that cabinet and soffit to increase ducting to 8" and install a wall-mount hood? This is a surprisingly difficult thing to Google. Not really any YouTube videos or blog posts outlining the process. I think I generally know what would be involved but always like to see the photographic play-by-play of someone else's undertaking first whenever I can!

Sorry we didn't have to remove any cabinets or anything. Took down micro, extended duct through attic and roof, put new hood in.

You sure you need to remove all that?

I'd advise finding a nearby carpenter or multi-functional contractor to advise you. It is difficult to advise from a distance, and difficult without some deconstruction for you to see what you have to do or even take enough photographs for remote advice. There may be another forum here to advise on these details, such as the HVAC forum.

But we haven't determined requirements so we don't know what size duct you need. This topic is widely addressed and repeated here. Size hood to fit, or better, to overlap. Determine hood entry area (sq. ft.). Multiply by 90 ft/min to get required CFM. Multiply by 1.5 to get blower rating. Using required CFM, choose a duct diameter such that the air velocity in the duct is between 1000 and 2000 ft/min. More constricted but short ducts may be acceptable.

HVAC forum, good thinking. I'll run my calculations and also see what those guys might have to say.

I could probably get by with a 600cfm hood and my current 6" ducting - it would definitely be easier. Going this route feels like it'll lend a little more character to the kitchen...though definitely more expensive.

Good thing range is backordered until who knows when so I have some time to figure it out!

Also, there are probably by now over a 1000 hood threads added since, say, 2008. Many involve hacking into an existing home, and some of these have digressed into the hacking part rather than just being limited to hood purchases or even hood requirements. All you can do here is search on hoods and sub topics of hoods and scan the results for relevant content. It may help to use an outside search tool with the 'houzz' or 'gardenweb' site URLs specified.

@timothy fisher what did you ended up going with?