Wow. Thank you for the detailed response . The greenheck guide will be very useful!

Be sure to read other hood threads on this forum, as well as make-up air (MUA) threads.

You need to ask yourself - how do I clean this? Filters of any exhaust system have to be cleaned of the grease they collect. With a standard hood, mounted so that the distance between the cooktop and the bottom of the hood are between 30" and 36", you just reach up slightly, pull down the (baffle) filters, and put in dishwasher. With a ceiling-mounted hood, you will have to climb a ladder both to take down, and to put back. But if you procrastinate this chore--cause who wants to get out the ladder to climb up to the ceiling--you run the risk of the filters getting so clogged they impede the hood's effectiveness, and may drip down onto the cooktop and you.

And with any filter height and scheme, the greater the risk of dropping a filter and breaking the cooktop Ceran (if not a cast iron gas cooktop) the greater the effort that must be made to protect the cooktop while messing with the filters.

No one seems to have one but many have negative opinions. I too would love to hear from actual users.

I vaguely recall someone here reporting that theirs was good enough for them. But I don't recall the details. Scanning all hood threads back for a few months might yield this example, or perhaps another member will recall the actual link.

I’ve never cleaned any hood or vent, period. I’ve never in my life seen grease drip from anything. We cook 2-3 meals every day at the stove for my whole life. I only use the crappy Otr microwave fan when there’s lots of smoke (once or twice a month) but I’m not sure it works because I always still have to open a window anyway. So, I’m just wondering how a ceiling recessed hood could cause all the horrors we are warned about. I have a friend with a mcm open kitchen/great room and no vent. When there’s smoke he cracks the window. 15 years and no issues - and he's way more of a chef than I am. I trust the experts, I do. But I haven't experienced all the horrors of improper ventilation I'm told to be afraid of.

"But I haven't experienced all the horrors of improper ventilation I'm told to be afraid of."

But many of us have. My last house was a MCM with no hood vent -- the vent was in the ceiling in the middle of the room. The filmy layer of grease that collected on the walls up toward the ceiling and on the cabinets was disgusting -- made worse by the dust that stuck to it. Furniture and decor items in other rooms even had a very fine layer of grease on them. What a constant mess. Finally had an OTR microwave w/vent put in, which was by far better but still not that great -- it at least kept the grease from dispering all over the place. At this house, the hood fan isn't a very good one (will be replaced soon), it has mesh filters and if I forget to clean them oh yes the grease DOES drip down onto the stove. So yea...agree with above comments about cleaning the filters and how likely are you to do it if you have to get on a ladder.

it isn't grease dripping, but the grease is cutting down on the effectiveness of the hood dramatically if it isn't cleaned regularly The OTR fan is pretty bad when clean so it may be hard to determine if it has lost any effectiveness.

The mission is to keep the grease from settling on cabinet surfaces by using the fan. Run your hand over the top of the cabinets and see what you feel up there - probably slimy. Test the fan by holding a piece of tissue under it and see if it moves

This is another case where reviewing many of the hood threads here should provide insights on requirements for good capture and containment performance.