"Have you thought of changing the wall studs to 2x6" rather than 2x4"?" I don't wish to destroy the wall on the far side. I have a large map wallpapered to the other side. I could build out with a false wall for some additional distance, but I don't see that as necessary since I can do at least 3-1/2"x14" (almost equivalent to a 8" round duct). Plus, I found a standard "Straight Register Boot" to transition to 8" diameter. I believe 3-1/2x14" equates to about .05 friction loss for five feet). I just don't know what 2200-2500 FPM will equate to in sound level at the hood. I foresee cutting a 4x15 opening (or bigger), at the back of the hood. I am re-reading rjpjnk's post and I remind you I only have five straight feet till it feeds straight into the fan venturi. I found this is an engineering handbook: Duct velocity should be between 1500 and 4000 FPM  Hood velocities (not less than 50 FPM over face area between hood and cooking surface)  Wall Type - 80 CFM/ft2  Island Type - 125 CFM/ft2  Extend hood beyond cook surface 0.4 x distance between hood and cooking surface Filters  Select ï¬lter velocity between 100 - 400 FPM  Determine number of ï¬lters required from a manufacturerÂs data (usually 2 CFM exhaust for each sq. in. of ï¬lter area maximum)  Install filters at 45 - 60°to horizontal, never horizontal Using this as a guide I think an average 400 CFM for general-purpose venting @ 1500 FPM means that I am well covered with a variable speed 1000 CFM external fan and 8" duct area. I'm guessing that at 1500 FPM it will be pretty quiet. The old Vent-a-Hood units are supposed to deliver 300 CFM each and I usually only use one. They are super noisy at near my ear level and 18 inches away. The air passes through a 3-1/2" x 4-1/2" rectangular opening! That's small and seems to equate to almost 3000 FPM! I guess it's no wonder they're so noisy... Am I missing anything? Bad calculations or asumptions?

We have a similar house design with a load bearing wall running right down the center from front to back. In our plan to open up the floor plan and widen the doorways the plan shows manufactured beams (laminated?) so that they don't get too tall and reduce the height of the doorways. The floor joists for my 2nd floor run left to right and from each side they run over and sit on top of the existing load bearing wall. They plan to put up temporary supports, remove the existing wall down the middle of the house, and then replace it with the laminated beam. We haven't had the plans go to the engineer yet, so the initial beam specs are just based on the projected span and the use of 4x4 posts to support the beam at each end and one point in the middle (total beam length is about 20 feet). The posts will be right on top of the steel I-beam that runs across the basement below. Bruce

Buehl, when I said, "Anybody? Bueller?" that was actually a play on a line in the movie Ferris Bueller's Day Off. I wasn't calling for you, but any help by ANYBODY at this point would be appreciated. P.S. That lead you sent me was a dead end. sandca, I take it you changed your mind about opening up that opening, no? Even your original quote is quite costly for me--that's 10% of the assessed value of houses around here! No wonder nobody does that thing in this area. Of course, if people live out west or down south in 200K-300K homes & made their fortune, perhaps they should head back East where they can live like kings on $4.99 prime rib roasts and $2.69 NY strip steaks and practically buy blocks & neighborhoods! What Tom's engineer/drawings costed, I could have bought half my new cabinets! I think I'll look in the basement tomorrow and see exactly where those support posts line up. Maybe someone can then explain the relationship of the location better; in effect, I'm trying to open up a 5ft wall that when done still will be supported at the ends of the 5ft span but no longer on three studs between the end points. Those 3 studs only span 32'', yet without cutting another stud on each side, a 46'' opening should still fit between everything without cutting more than 3 studs--enough for 2 people to sit at. Enlarging the door opening I'd probably just need to go to the next stud on the right, which should be another 12''. I just figured if I'm going through all this, then it may just be easier installing one laminated beam from the left corner of the wall to the stud at 32'' from the right corner. Total width from the left corner to the 2nd last stud would be ~8.5ft.

It really is not that uncommon for builders to just mass produce headers out of the same materials. They just size them for the largest load for the project and don't worry about individual calculations. The material cost difference is pretty minimal and you can get away with using less experienced labor if you don't need them to think about a bunch of different factors. You just have someone making 10 "doors" and 25 "windows" all in a row and pop them in as you go. Of course, that is why you hire an engineer to tell you why things were done and if you can change them. As a practical matter, you can turn just about any doorway into a wider entrance. If the wall is load bearing, you just need to size the header appropriately for the load and span. A triple 2x10 is probably enough, but the engineer should do the calculations and let you know. You don't put a header on an L bracket though. You'll need a 2x6 under each end and then another 2x6 running on the outside running continuously from floor to ceiling. You'll almost certainly need a longer header. If you are planning to do this yourself and it is load bearing, remember to build a temporary wall to support the load before you take down that header or any of the 2x6 studs.