I hadn't seen this thread when it appeared in Oct. I actually find it kinda odd. The OP has never posted again. Maybe it was indeed spam? Either way, I have really found the original Range Hood FAQ very helpful, and have emailed the link to friends cause it's such a good summary. I don't think the OP has added anything helpful to the hood FAQ, and his additions might confuse someone new to the Appliances Forum, or someone struggling with hood choices (the hardest choice for me in my kitchen!). As others have pointed out, it's odd he chose a 36" hood for a 48" range. Odd that he doesn't mention Wolf hoods in his discussion of high-end hoods, even though that's the range brand he chose. Why does he say baffles are not standard in high-end hoods - that's incorrect. And indeed, despite his contention, the greater component of noise in a hood is the airflow. You can have two identical hoods in two homes - the home with the problematic ductwork (i.e. more bends, longer, or narrower) will be noisier despite the identical motors. I think the Futuro hoods are a good brand, judging by what others have enthusiastically written on the Gardenweb about them. But I hope that people looking for helpful info on hoods in general will look at the original Hood FAQ rather than the OP's additions.

Well, I'm one of those people who spouted off the top of his head about rigid ducting. I'm a health economist by training and self-taught in HVAC, electrical, plumbing, etc. So you need to take everything I say with a grain or two of salt :) There are different types of flexible duct. Heating often uses wireflex, which is insulated and the inner coating is plastic. This is good for forced air heat, but not for venting a stove. There is metal flexible duct-- like the kind you probably have behind your dryer. Then there is rigid metal duct. I did the venting for my hood and used rigid duct because my GC who was doing the framing, said that is what I needed. Perhaps it would have been fine to use flexible metal, I don't know. I have no data on which is sufficient for code. Flexible and rigid metal differ with regard ease of installation. Rigid is a pain to work with, so your contractors are likely to want to use flexible. I would take the statements that your hood is too big with a grain of salt. When I worked with Prestige to identify our blower volume, they recommended a min of 1000 cfm based on my needs. Unless your contractor knows your needs well, it is hard to make blanket statements about what is too little or too much. Sorry if I couldn't be of more help with regard to code specifics.

a false beam is a good disguise. We cannot say if it matches the rest of the house. If the galvanized steel ductwork has to be tacked on to the ceiling, then any dropped ceiling, or dropped section, or soffit-looking thingie, or beam-looking disguise, is a good way to cover it. You can paint it too. You can wrap it with anything and call it done. It's definitely a problem to work around. In your second post, ramica, you mentioned a 2 inch gap. I think this is a better problem to work around. I think this is worth a lot more attention. My hunch is that a good answer is somewhere here. If the ceiling is not a concrete slab, it is made of joists, and is almost entirely hollow between the joists. The direction the joists go is the same direction that your ugly metal duct can go, too, for the first few feet. It might not matter at all if that direction is perpendicular to the direction you want. When the duct nears a wall, a transitional piece of ductwork can turn the air stream 90 degrees. This transition piece matches up to a run of standard size duct work that travels along the wall-ceiling junction (which can be covered by a soffit) over to the exterior wall hole where the duct is to go outside. http://en.wikipedia.org/wiki/Soffit ....formed as a ceiling .... fix underneath .... underside of any construction element "boxing it in and painting it white" is a soffit. In a kitchen a soffit can become the place for pot lights directly overhead of the workspace (countertop). So, this is worth considering. A 3.5" by 10.5" rectangular duct is the right size for a flow of air much smaller than your 600 CFM flow. A 3.5" by 10.5" rectangular size of duct is good for rental apartments with electric coil stoves and cheap exhaust hoods. ( ... "I am told the ductwork should be 3 inches high by 10/12 inches wide." ...) A 600CFM stream will need a larger duct. The right duct size is specified by the manufacturer. It will be in their product's PDF on their web site. What size round duct is it? I'd say 8" is my guess. It could be another size. Transitioning to an appropriately sized rectangular duct is easy once you go get the right information. Snoonyb posted in the first reply you got in this thread, asking about joists. Your answer was the wrong one. The next post from someone was from loves2cook4six who asked the same question that snoonyb asked, although the question was worded SO differently that it might appear to be unrecognizable. Then you mentioned a new beam, going the other way from the joist direction. I believe there is a way to go through the support beam "from the addition" even though it is running the wrong way. In the remodeling forum you will get experts telling you how to reinforce a beam in such manner as to allow you to cut a hole through it. I believe there is a way to send the duct through the empty space above the new beam and between the joists. This may be the optimal path of study for you today. Remember that the new beam is perpendicular to the set of joists in the ceiling, and it does not fill the empty space that is still there and just as much available as it was before the new beam arrived. Hth

Well THANK you Weissman, Breezy and Madeline for your strength on this! I'm recharged to have it done properly, according to Code. DH is on board with this too. We do not have a GC so will have to take the stand ourselves. Madeline, I was unaware of Coburn's. The closest one is in Athens TX, about 1.5 hours away, but I'm going to call them tomorrow. Thanks so much for sharing that. At least mine does not go up into the attic -- it is all self-contained in the hood itself, and goes straight out the wall behind the hood. But your point is well-taken -- one squish or kink in the flexduct and that can ruin the whole reason for having it. One more question for you: I see his problem. There is no access panel, so how is he supposed to get his hands up there to connect the unit to the rigid duct after he has pushed it up into the wood hood? Thus he's saying he needs the flexduct to dangle down... BUT, don't you think that with precise measurements and good care, he could arrange and position the rigid pipe so that it mates up perfectly with the unit when he pushes it up there?? Or should the cabinetmaker have made some kind of access panel on the front of the hood? I see a lot of pics of hoods that definitely don't look like they have access panels. I've just spoken to our plumber about this, who's coming tomorrow to hook up the sink etc., and he thinks the above is do-able (mate the two pipes as the unit is being pushed up and positioned.) What's your experience on this? Thank you again, I'm so glad I asked.