Hmm. I thought I already replied to this, but I don't see it. I have 7'6" ceilings, and a range on a peninsula. I used a VentAHood EuroPro island hood. With this hood you must order the duct cover custom. Mine was 6" tall! (The hood itself is 18".) This gives me the recommended 30" spacing between counter and hood. You should be able to order a 4" duct cover as well. Its not a cheap solution. My duct cover was over $300. But it looks nice and works well. Here is a picture: Its not a great picture, but its the best one I have handy that shows the hood transition to the ceiling. The way this works is that the duct cover is bolted to the ceiling, and the hood hangs from it. Mine was installed flush with the framing and the ceiling installed around it.

I have your same problem but have no option to enlarge the vent duct due to the size of the space between the wall and ceiling studs. My previous vent hood was a 36" Cavaliere 900 cfm for a 36" Dacor Epicure cooktop. My new range is 36" DCS with 6 burners. Because I wanted a more substantial look, and after much searching and debating, I bought an AirPro 860 cfm (link below) The Cavaliere hood was more than what I needed for the 36" Dacor. I never turned it up past 1 or 2 while cooking. On 6, the highest speed, it was kinda loud but since I never used it on high it wasn't a problem. The AirPro has not been installed yet so I don't know what the actual noise level will be but it's rated at 35 / 0.7 to 67 / 6.5 (Lowest to Highest Speed). I just couldn't see paying thousands of dollars for a vent hood especially since my $400 Cavaliere had worked fine for 5 years. During my hood research one of the retailers did tell me there was a vent outlet adapter available online but because our contractor wasn't thrilled with that idea, I stayed with the 6" hood duct. Hope this helps. Good luck in your search for the right hood. Here is a link that might be useful: AirPro Hood

houses14, my Imperial range hood is not an insert, rather an under cabinet ss hood. However, the materials used, and the quality of construction, the fan motors, are the same with minor variances to allow for space restrictions within the smaller size of my hood. Construction wise, it is all that I had hoped for, was easy to install, and has functioned beautifully. Packaging and shipping were excellent. The ss is marine grade. This means that the amount of chromium in the ss will prevent rust from forming in the interior of the hood over time. The electrician informed me that their fan motors and switches appeared to be top quality. The warranty for my hood is 7 years, which is almost unheard of in the industry. Their specifications and installation instructions are right on to allow for optimal operation. For example, my duct is 8" from hood to roof jack and had to have a certain rise in height from the hood before the first angle in the duct work. Baffles remove and reinstall easily for cleaning. It was a joy to call Imperial direct with technical questions at their manufacturing headquarters in California. Someone was always immediately available to answer my questions regarding their vent hoods or recommended installation. My installer was promptly referred to their engineer for technical assistance as I requested that the wiring that would automatically turn on my hood once a certain temperature below the hood was reached be disconnected as I did not want that feature. To me, having that level of service available when answers are needed means a great deal. I found that the folks at headquarters were always honest even if it wasn't the answer I wanted and that they knew their stuff. Their light and fan switches are continuously variable which is rare on vent hoods. This means that they both function like a rheostat with a continuous increase, or decrease, rather than clicking up or down discreet notches, such as level 1 to 4. Also, I liked having the option of installing the switches wherever I wanted remotely, rather than being mounted to the underside of the hood. The hood easily handles removal of odors, steam or grease beneath it's surface. I've found that if the hood is allowed to run for about 10 minutes prior to cooking that it can be operated at a lower level and do a good job. The hood on low is fairly quiet but is noisier than I had anticipated at higher levels with having dual fans and baffles. Also, highest cfm level is 1000 which is a factor. However, I used a different size led bulb than Imperial recommended. I now have a gap around the bulb that needs to be filled with a rubber gasket. Also, the temporary roof jack is too large, and the correct one is waiting to be installed so the jury is still out on the noise issue. Noise level was quite an issue for me, but even if it remains unchanged, I would still buy the same hood given how pleased I am with the overall operation and that I can easily live with the noise that I now have. I'll have to look up the name of the online vendor I used and will add that information tonight.

I only saw one Ventahood where I could try to figure out if the cleaning or the more raw underside would bother me, and it was not connected to power so I don't know about their sound level. I've heard they are quieter and I've heard they are louder. I think the looks of the cages vs baffles would be more of an issue for me. While I was trying to decide whether that was a bit "raw" looking, I was led to a guy at the place where I bought my appliances who said he'd seen and heard both side by side. He said the Best by Broan was better for sound and operation, so I went with it. Very scientific, huh? Unfortunately, buying a vent is like that. I have a 1200 cfm model with an external blower and got the baffles. The blower sits just above my sink on the opposite side of my kitchen (better than the toilet or shower straight above --LOL) and it is quiet when you are outside. I'm not sure that in my set up the remote blower made that much difference. If I'd have another inch or two, I'd have been able to put in a silencer. Most of the time, I run the vent on the lowest setting or up to about 1/3 power -- rarely over 1/2. At that level, the fan on my ovens is as loud. You barely hear it away from the vent, but you will standing right under it. At full power, you will hear it, but even then it is not as loud as the ineffective downdraft my last cooktop had -- with only one speed. If you turn it on when you first start cooking and run it higher for things like fish, popcorn, bacon, you will not smell them all over the house. I made 120 bags of popcorn, both on the stovetop and in the microwave (bags opened under the vent)one afternoon. I delivered them to the school, came home and could not smell any popcorn. Maybe it could be more perfect, but I'm happy with my choice.