...it needs to be a 6" duct. Unfortunately, the Kobe, which looks like exactly what I want (but do not want to pay for) specifies a 7" duct. Just regarding the duct size issue, I wouldn't normally recommend going with a fan that needs a larger duct than what you have. HOWEVER, in your case, it's only a 1" size difference, and you have stringent requirements on the appearance (i.e. glass canopy), and you say that this model is "exactly what I want". Kobe also has a good reputation on this forum for making quality hoods. The consequence of your 1" difference will be a somewhat noisier hood. There have been posts on this forum from people with 6" ducts using hoods that need 8", who experience more noise, but that seems to be the only consequence. It'll depend on you whether you feel, quality-of-life-wise, that consequence is a significant one. As to the price, how out of your budget is it? I have found that with my kitchen re-do, I have sacrificed some things I originally planned for in my kitchen for some things I really wanted. I.e. I re-jiggered where I was spending money. There's several cabinetry options I decided to forego in favor of some other things, and I don't think I'll miss them. Is there something else in your kitchen you can sacrifice in order to get the hood that you say is "exactly" what you want"?

What about a chimney style like Angie posted? Have the chimney go to the ceiling, but have it vent out the back over the window - like I'm assuming your "under the cabinet" hood is going to. It will look like it goes to the ceiling and vents out, but in reality it will vent out the back. I also think if you get more cfms in either situation, you will be better off. Try for 1000 or more cfms, 6" wider than the cooking surface, and at least 24" deep (27" would be better.). I think TrailRunner has a hood mounted higher than recommended, but, she has higher cfms than you're talking about...1400, I think. If a hood is mounted higher, you can sometimes make up for it by getting higher cfms and a wider/deeper hood. Good luck!

From reading here it seems as if modifying chimney heights at the ceiling is not uncommon. If hubby thinks he can do it, he probably can. If not when he sees it, look for a sheet metal fabricator. Maybe even AC installer types - they do a lot of sheet metal fabrication on site for their installs. From specs I've read for vent hoods there is a range for most above cook top height, usually 27" to as much as 36". Maybe related to cfm. Remember too that the back of the vent is ~2" from the back edge of the cook top edge and 2-3" from the front of the cook top, so the front edge of the hood will be 5-6"away from your cooking vessels. And you don't usually hang your face right over a cooking vessel. I suggest going to some displays that have vent hoods over cook tops/ranges. Measure the heights from the cooking surface just in case they are especially high or low. Take a pot and pan with you and see where your face and forehead "fit" in relation to the hood edge. Measure some more. I don't think you have the problem you are anticipating, or at least not a problem that cannot easily be fixed. You got a good deal? Great 'cause vent hoods are really expensive! Enjoy.

The CFM per BTU/hr rule of thumb comes from commercial (and fairly standardized) cooking appliances vs. their (fairly standardized) overhead hoods.* Neither the cooking zones or the hoods are a particularly good match to their residential counterparts. A better rule of thumb, in my view, and more aligned with the action of the hood, is to ensure that the velocity of the air/effluent that reaches the hood baffles is high enough to ensure that there is no smoke reflection from metal parts back into the room. I recommend a velocity of 90 ft/min. Because we don't have a way to shut off parts of the hood that the effluent doesn't reach when only certain burners are operating, this velocity has to be achieved over the entire hood aperture. Hence, the hood requires an actual flow rate of 90 CFM per square foot of aperture, independent of the number of burners that are operating. (This is for maximum cooking surface temperatures (smoke point of peanut oil, for example, when wokking) and for gas burners. With induction, there is no combustion hot gas entrained in the cooking plume and its velocity is a bit less. At lower temperatures, the flow rate can be lower because the rising effluent velocity will be lower. However, at low air speeds through the baffles, there will be less grease collection by centrifugal impingement. I successfully use about 90 ft/min over my induction cooktop and nearby induction wok hob with an island hood. Your plumage may vary.) Our hood blowers use a fan blade design that only supplies the flow rate listed for the fan at zero static pressure across the blower; i.e., with the blower hanging in free air. When mounted in a hood, or in a duct, or on a roof, the blower sees restrictions. These include the baffles (or mesh filters), the pressure losses from turbulence -- both at transitions and from the duct walls -- and from similar such losses in the make-up air (MUA) path. There is always MUA. How much you get vs. how much you need determines what the actual flow rate of the hood will be due to pressure losses across the blower. So whether or not a municipality requires a deliberate MUA system, or the cook opens a window, there has to be good flow into the kitchen to make up for the flow out of the hood. Else there won't be much flow out of the hood. Even with reasonable MUA, there is enough pressure loss in the loop from cooktop to outside and back to cooktop to significantly degrade the rated blower CFM. I recommend choosing a blower that is rated at about 1.5 times the calculated required CFM from the 90 CFM/sq. ft. rule. There are also safety aspects of adequate MUA that may apply. Hood overlap is important to minimize the grease that escapes the hood and condenses on the rest of the room. In a wall application where there are side cabinets, the air flow toward the hood helps direct the rising effluent toward the hood, so the hood's effective capture aperture may be a bit larger than the physical aperture, particularly if there are no drafts that displace the smoke away from the hood. Mounting the hood out from the wall can also help, but the filler plate at the back should be angled to aid reflecting the effluent toward the aperture rather than down. kas ----- *For a description of both methods of CFM requirements estimation (from a commercial point of view), as well as images of smoke capture and containment vs. smoke capture and failed containment, see Greenheck's "Kitchen Ventilation Systems Application and Design Guide" (KVSApplDesign_catalog.pdf) available from their website. http://www.greenheck.com/media/pdf/otherinfo/KVSApplDesign_catalog.pdf MUA is also addressed in this paper. Note that all Greenheck CFM requirement values are actual flow rates, not blower CFM rating rates, and that balanced air pressure MUA is present in the commercial kitchen.