We had our hood built to extend out from the wall 27 inches, and the cabinet maker did a beautiful job. It's built to hold a ModernAire PSL-040 hood insert, with a remotely-mounted (attic) Fantech 1266cfm fan pulling the exhaust through ten inch duct and one of Fantech's garbage-can size silencers. The hood fits snugly to the adjacent cabinets on either side, which of course don't extend as far forward as the front edge of the hood. Unfortunately, the hood (which doesn't have the insert in yet) was set even lower than Capital recommends (the hood is wood, and only about 29 inches from what will be the cooking surface of the range. ModernAire recommends a range of 30-36 inches between cooking surface and the hood insert, so our hood's going to get moved up about seven inches. Headknocking may be "overrated" for some, but at 6'4", I'll crank up the gain on the fan (it's an infinitely variable switch) if and when I need to in order to avoid it. I do all my grilling outside, and most of our indoor cooking won't necessitate that kind of capability. But it's nice to know it's there when we need it. :-) Here is a link that might be useful:

I'm 6'3", and have the Wolf 36" 4 burner/griddle rangetop and the Wolf 42"x27" hood (900 cfm internal blower). It's recommended that you go with a 42" hood for a 36" range or rangetop so that you have better capture of the heat and smoke/grease. The variables you can play with are the mounting height and the depth of the hood...24" or 27". It's also recommended that you mount the hood around 27" above the range...check the Wolf specs. I also thought I'd be bumping my head and really uncomfortable cooking, so I raised it to 28 1/2". I was concerned about not getting cooking grease all over the house, so I didn't go any higher(open kitchen/great room floor plan.) I also had a soffit beam there that couldn't be removed, so that limited my mounting height to nearly the recommended distance. It works great at that height, and if it was any higher above your head you'd probably not get much effective capture. Measured from the ground, mine is mounted so the bottom of the hood is around 65 1/2" off the floor, about 5 feet 5 1/2 inches. I cook mainly on the two front burners, and use the back burners for simmering, so I can easily reach and see inside the front pots, and still reach the back pots. I definitely have to stoop to get under the hood to look directly down into any pots on the back burners, but honestly, I really don't do that much...I can still see the contents from the front of the stove. Once I got used to the configuration, it became second nature. I agree with the previous poster, and I did the same...mock it up with cardboard and lines drawn on the walls.

I've got the two blower VAH, 36"W, 24"D, 30"H. It's the bare minimum. I have a 36" BS range top. While I would have preferred to go with the bigger arrangement, it will work for me. I don't think I can remember ever using all six burners at the same time. I don't plan to in the future. It was already installed and I didn't want to replace it. If I were building from scratch, I would select the 42", 24"D, 30"H with the three blowers. The 30"H arrangement with any hood will bother anyone taller than 5'5". My husband is always hitting his head on it and cussing. I really don't think you need a 27"D hood. BTW, I love the VAH. It works. There are videos on line that show you how to clean it. Easy after the first time.

spent most the day looking at ventilation systems. Thinking about replacing current system with 10 inch rigid ducting, broan external blower 1200 cfm (not that much of price difference compared to lower CFM https://www.homedepot.com/p/Broan-NuTone-External-1200-CFM-Blower-for-Broan-Elite-Series-Range-Hoods-335/100025769#product-overview, and broan hood shell 30 inch with 24 inch depth https://www.homedepot.com/p/Broan-NuTone-Elite-30-in-Range-Hood-Shell-with-Light-in-Stainless-Steel-E60E30SS/202905883?#product-overview. I didn't look too much into silencers but I think this is what you all are speaking of in the forums I've read so far... https://www.supplyhouse.com/Fantech-LD10-Galvanized-Steel-Silencer-for-10-Duct.  Waiting for broan to respond about a duct cover since i dont have a cabinet there. I looked at faber, but nothing is available with higher than 600 cfms at 30 inch depth (must keep that depth because my cabinets are in the way). Also looked at prizer, abbaka, bluestar, z line, dacor, GE, stuff at home depot, stuff at costco, stuff at friedmans but something was either the wrong size, cfm, or not available. There is a fivestar that works but no pictures to see if the inside of the hood is "tent" shaped as recommended by @kaseki. @Joseph Henderson any other recommendations for good value brands? I looked at wolf too but the duct cover was so expensive! I started my journey contacting HVAC professionals in the Los Angeles area to see what they would recommend, but I haven't had much luck finding someone who does vent hood installation or would recommend something roof mounted which I found frustrating and odd. One company did recommend a KOBE internal hood with 600 CFMs https://www.homedepot.com/p/KOBE-Range-Hoods-30-in-600-CFM-Stainless-Steel-Wall-Mount-Perimetric-Range-Hood-with-Flame-Temp-Sensor-Auto-On-Off-and-Fan-Control-CH7730SQ6-WM-XX/310852212 which would cost 2500 including hood, installation, and "ducting changes". I found it a little odd that his recommendation for hood CFM was so low and the hood actually does not require any ducting changes whatsoever (Duct Width 6 inch). Another company had someone come in for an estimate and then said they wouldn't be able to give us a quote for a month due to covid. Another company I called for recommendations said just pick the appliance and he will install it. When prompted about what he would recommend he said usually the more expensive the better... Would love to have any recommendations for installation in Los Angeles area if possible since changing the ducting does require cutting a hole in the roof and futzing around my attic. i feel as though this is a VERY important part. havent heard back from friedmans (who sells appliances in our area) @M yes, I was on houzz forums last night reading about flexible ducting and fearing a house fire X__X larger rigid ducting is definitely at the top of my list. @Buehl I am limited by cabinets on each side, will definitely look at something deeper at least 24 in, seems like there aren't a lot of options that are deeper than that. I appreciate everyone's input. You've been more helpful than the professionals that I've contacted! I've been looking through houzz forums I can't believe @kaseki responded directly to my post! thank you so much it really seems like you know what you're talking about I will definitely look for 800 cfms and up.