>>It's interesting that there's crown molding on the columns and a lot of detail on the wall, but no crown in the kitchen. Is there crown molding elsewhere in the house?Oh my, have you hit on a sore subject. Crown molding was only included in the formal areas and master bedroom. They also crowned no sloped ceilings. Adding crown to other areas was $250 per "room". $250 now, not so much. 20yrs ago when we're building a house and running out out money, it was. Crowning just that hallway and the adjoining family room cost $500 because it counted as 2 "rooms" even though it was only as much crown as a bedroom; the exterior wall is sloped so the family room is really only 1/2 crowned (one wall not crowned and open on one side). I didn't crown the kitchen because the only wall that would have received crown is that single wall (because again, the outside wall is sloped), and it would have cost me $250. Don't think so. I did the crown in my office myself (come on -- a box) along with the sloped ceilings in the formal living room. If *I* can do it, why in the heck couldn't a carpenter? New cabinets will go up to the ceiling in the kitchen. They put tile crown where I cared in the master bath when it was remodeled. What I should have done was made them crown the hallway to the bedrooms just to punish them. It has so many compound angles it would make any carpenter cry.

Many years ago our cats would stare at the fireplace in February. Then a big fat fly would crawl out and they would play with him. My wife sniffed by the fireplace and announced something was dead behind it. I unzipped the vinyl siding to the chase the next day, cut the sheathing with my Sawzall, and using a bent coat hanger, pulled the bones and fur of several dead squirrels from between the metal chimney layers. There were bug carcasses all over in there and it stunk to high heaven. They would fall between and could not climb back up the slick metal. I spread Fabreeze around, buttoned up the chase and siding, and put a mesh cap on the chimney and didn't have a problem again until the guy in the condo next door invited us over and Ms. Sniffer stood by the fireplace...

Calculating the correct hood size is not entirely trivial and can depend on a lot of different factors, but @kaseki has come up with general guidance that is frequently quoted in this forum. And from my own experience, I can confirm that it gives numbers that are a good first approximation for what you need. The main insight is that cooking plumes rise with a speed of up to 90ft/min (with bursts exceeding this number). So, this is a good number to aim for, if you want to actually vent the majority of effluent; and everything else follows from this number. Hot air rises in an expanding cone shape. As a good rule of thumb for a hood that is mounted at average height, attached to a back wall, and has upper kitchen cabinets at both sides, making the hood about 3" wider than your range would allow you to capture most of the cooking fumes. This means, for a 48" range you are looking at a hood that should be at least 54"x24", but increasing the depth to 27" would be preferable. You also should have some amount of "boxiness" instead of just a flat surface. The box helps deal with air that bounces off surface of the baffles and with bursts of super fast air (i.e. in excess of 90ft/min). This is the aperture opening that has to be able to move air at 90ft/min over the entire area. You can make the insert a little smaller, but you shouldn't go much smaller than the aperture size. For argument's sake, let's assume that your capture area is 10 sqft. Then you would need to move 90*10 = 900 CFM. So, your stove manufacturer agrees with us. Wonderful! All of these are rough estimates anyway, but if they are in the same ballpark we know that we are not completely confused. Until this point, we have been talking about actual measured airflow that we have to be able to achieve. Unfortunately, the second part of this question is how do you actually go about achieving this airflow. And that's where you have to realize that hood manufacturers use very creative math, when advertising their products. They measure airflow through the hood, when there is zero back pressure. In other words, there is no duct attached to the hood, and the hood isn't actually venting to the outside; so, there also is no concern over make-up-air. In these idealized conditions, your hood very well might achieve 1000CFM at the max power setting. But in practice, there are all sorts of performance losses, and even very minor back pressure typically results in quite a sharp drop off in CFM. It's rarely an easy linear relationship. A good HVAC contractor who installs an oversized, very short duct without any bends can probably minimize losses, especially if paired with an active MUA system that provides positive air pressure. In practice, these ideal conditions are never met. So, short of precisely measuring the physical properties of your specific system, @kaseki suggests upping the desired CFM by 50%. In many real-life scenarios, this rule of thumb has worked quite well. And that means, you should aim for a hood that is rated for at least ~1400CFM, and that's assuming that you did everything else right (i.e. short directly venting 10" ducts and an appropriately sized MUA system). Of course, all of these interconnected parameters have some play. If you cut corners in one part of the system, you can sometimes compensate for it in a different part. We have a 30" range and decided on a 1200CFM hood, and we are very happy we did. The duct is large and not extremely long, but it does have some bends that might affect performance. But most importantly, we rely on an open window for MUA. This is not ideal, but works as we live in a part of the country that "doesn't have weather". So, this window stays open year round, and it's a significantly large window. Also, we have no other gas burning appliances in the same envelope. So, building inspectors usually let things slide. And in practice, the fact that we oversized the hood for our stove does a great job making up for the compromises made in other design choices. Despite an open floor plan, our hood vents perfectly and there never are any lingering smells. This certainly wasn't true before the kitchen remodel. But it is important that the window stays open at all times when cooking. And if that's not an option, a more elaborate MUA system would have been required.

Let me emphasize a comment above: For greasy plume capture the hood has to overlap the cooking area because the cooking plumes expand as they rise. This requirement leads to rectangular hood openings, not circular openings. For examples of island hood sizes, you can review the Wolf Design Guide, available at Subzero Wolf's web site. Also, a tour of AJ Madison will reveal probably hundreds of options, perhaps less expensive. Keep in mind one almost never gets more than he pays for. Flow rates (CFM) to assure containment are based on the same parameters as published here in numerous hood related threads. A properly sized hood with adequate CFM should minimize the need to clean windows and walls behind the hood. Climbing on stone counters, if used, should be avoided in any case.