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Some of the responses worried me about negative back draft but I think I’ll be OK. We’re installing a professional style residential Viking 36″ 6 burner range with Viking hood and used the recommended 7″ round duct. We have wall board up on 3rd and 2nd floors…still open studs on first floor.
The kitchen has 10′ ceilings & 3 fireplaces; 2nd floor 9 foot ceilings & 3 fireplaces; 3rd floor 9 foot ceilings and 1 fireplace and dormers. First 2 floors of the house are about 5800 sq feet. Duct is going straight up through the wall and vented out through the roof.
Does anyone see any problem with what we’ve installed for duct work? We followed Viking’s specs.
I’m hoping and assuming Andy’s solution will work for us should we not have a back draft problem.
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I read all posts and am quite interested in yours. I saw both the Viking and the Vent a Hood blowers/hoods demo'd at a place called Delia in CT.
I was amazed at how quiet the Vent-A-Hood is although at the highest speed it sounds like a lot of rushing air - like a car window is slightly open. AT high speeds the viking is quite noisy...but it will be rare that I would enough burners going to warrant high speeds all the time.
I did wonder, thought, if it having only one speed was better or worse than the Viking with variable speed blower, although with vent a hood one or both blowers can be turned on. Hubby prefers the "look" of viking to match the stove; I'm impartial...I want performance.
We are not using a remote blower...the blower will be in the hood over the range.
But now I am quite worried about two things
(1) that we will have a back draft problem, and
(2) that the duct is not large enough. The viking specs say 7" round; 8" is to be used for downdrafts and 10" round is to be used for exterior ventilators, or for 48" ranges. We bugs us is that we would have to pay our installer AGAIN to do the job again (to remove the wall board he installed (thank goodness its screwed in and not nailed in)and will have to dismantle the old and rebuild the new duct).
But if you or anyone in this thread feels that we really do not have a large enough duct, PLEASE tell me now. We have about a 30' duct run with only one 45 degree bend which is where the duct comes into the attic space and bends to follow the pitch of the roof rafter about 4 feet before it goes through the roof.
I am concerned. I want this to be right. We have to decide what to do before our plasterer plasters the blueboard that the duct runs behind.
Please....advice is greatly appreciated.
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Looking for experiences or advice on installing and venting a 600 cfm commercial stove hood(for a Viking 36" cooktcook top) was told this would create a negative pressure in the house and will need air recovery system? The vent pipe will have to go up through the second story and vent out the side of a gable (1- 90 degree bend) any rules/regulations I have to deal with. Would like to mount the blower remote to the hood.
*What are you trying to suck up with this thing? If you install it in a 3000 sf house with 10' ceilings you'll suck all the heated air out in less than an hour. You are going to have extreme negative pressure problems. You stand a good chance of back-drafting any gas applicance in the house, to say nothing of a fireplace or wood stove.
*Mike, the 600 CFM mentioned is thei minimumrecommendation for this kind of hood/cooktop configuration. Steve, I assume that you are using the term 'commercial' generically and that what you are really talking about is a Vent-a-hood or Thermador type hood made for pro-type ranges and cooktops. You should not be using 'real' commercial appliances in a house - the heat is too high. At 600 or 900 CFM (typical) you'll probably have a 9" or 10" round duct. Don't cheat on the manuf. requirements for duct size - take that very seriously. Avoid bends and reductions in size. Generally I haven't had the problems that Mike describes, but it wouldn't hurt to provide tempered makeup air - it's just expensive.Remote mount is a real improvement with regard to noise, but be aware that these ususally go through the roof, not gable wall. A roof termination, while usually fairly low, runs to a large footprint (like 22" x 28") and can be quite visible, although not as visible/ugly as a wall termination.Jeff
*Thanks for the advise so far. Jeff you are correct I will not be installing a commercial cooktop but rather the professional series like the thermador. How is make-up air introduced. Is it one of those HRV units. How do they work, any links I can got to to better understand.
*I do have a real commercial stove - 6 burners, 2 ovens, broiler and grill - 800 lbs. of Vulcan-Hart stove and it's been in operation for 25 years. It doesn't generate too much heat in my house and the commercial equipment dealer installed a 60 inch Thermador hood with venting to an adjacent porch roof. Works fine, never had any problems.What I don't understand is why people spend the money for commercial look alikes when the real thing is cheaper, easier to repair and lasts forever. Convents and other religious facilities that are disbanding are great places to find this equipment in mint condition for a couple of thousand - a lot cheaper that the 5 to 7 thousand for what is essentially a gussied up consumer range.
*600 cfm out = 600 cfm inbesides the backdraft problems...if you induce a negative pressure on the house you will get leaking problems you won't believe....in rainy weather you will suck water uphill thru every conceivable crack...the hrv would be a great starting place.....
*Mike, when doing commercial kitchens, we couldn't allow for 100% makeup... the norm was to be 80 to 90%, to ensure complete drafting of combustion by-products. NFPA standard I think.HVAC system needed tweaking accordingly... (more $$).Steve, do install make-up air. It should come in near the rangehood, some new systems have it inside the range hood.Ed G., the main difference in a "Commercial" vs. "Gourmet" range is insulation. The home version is usually a zero-clearance. Commercial ranges need a certain airspace and a non-combustible surface to the top, back and sides.
*We've got a Viking whose hood moves a lot of air. In the winter, when the house is closed up, it will backdraft the chimney. Our solution? Open a window in the kitchen, then close it when the fan is turned off. No backdrafting, cold air cooling the hot kitchen, problem solved.
*I too use only commercial ranges. A 60" Garland or Imperial runs around $3,000, compared with $10,000 for the residential pretend type. And the burners give off 28,000 btu compared with 15,000. The 2 issues are zero tolerance (as above) and pilots vs. electronic ignition on the burners. Also, it requires 3/4" gas supply.If you plan for this in the kitchen installation, with non-combustible floor and wall, it's a breeze. If not, it's a danger.The last hood installed came from a company called rangecraft, 1200 cfm with a 10" round duct. I will NEVER use a rangecraft hood again. The hood is hardly as big an issue as it seems, because the residential use is very different from commercial. The range doesn't have all burners cranked at all times, so the heat level never reaches commercial use. Similarly, the hood isn't on for 12 hours every day, so the need for replacement isn't that big a deal. A cracked window when you're cooking up a storm on Thanksgiving will do the trick. And 600 cfm, frankly, isn't a big deal. SHG
*Steve,I am in the middle of a kitchen remodel, and will be having a range hood custom made for it. I purchased a Fantech Model #RE(C)6, roof-mounted fan to use with it. It uses a 6" duct, and moves 227 cfm at 0.0" static pressure. They also have 8" and 10" models available. I am also including a speed control with it so that the homeowner can adjust it to the appropriate volume needed.Contact Gary Church-Smith at Energy Federation Inc. at 1-800-868-0660 x423, and he will be happy to discuss your particular application with you.Their web site is "http://www.efi.org"They also have wall mounted fans available.
*Some of the responses worried me about negative back draft but I think I'll be OK. We're installing a professional style residential Viking 36" 6 burner range with Viking hood and used the recommended 7" round duct. We have wall board up on 3rd and 2nd floors...still open studs on first floor.The kitchen has 10' ceilings & 3 fireplaces; 2nd floor 9 foot ceilings & 3 fireplaces; 3rd floor 9 foot ceilings and 1 fireplace and dormers. First 2 floors of the house are about 5800 sq feet. Duct is going straight up through the wall and vented out through the roof. Does anyone see any problem with what we've installed for duct work? We followed Viking's specs. I'm hoping and assuming Andy's solution will work for us should we not have a back draft problem.
*i It uses a 6" duct, and moves 227 cfm at 0.0" static pressure. Whoops - how are you going to achieve 0" static pressure? And 227 cfm is pretty minimal especially for a range hood. IMO the speed control isn't necessary - only full speed will do! Call Energy Federation back and ask them how to get the SP to 0".Jeff
*Back vent it from up above thru another vent so you won't loose heat or cool in the house.. Also you may have to have seamless duct work and insulated from all combustables. Its been a few years since I have installed these and it was commercial applications.
*I'm not a real fan of Viking's hoods. Their hood line is more of a filler to round out their product line. My opinion. I like Vent-a-Hood's line much better, with the ISF30 flareline model (island cooktop) looking especially elegant in high-ceiling applications such as your house. Many other models to choose from to suit your own taste.I'd want a larger duct for your approximate 25' run. I'd use an 8" duct minimum, especially if you're using a remote blower which will require a higher CFM. Going from 7" to 8" only increases duct diameter by 1" or about 15%, but increases potential air volume by an additional 30%. One of the biggest mistakes I see is a setup that requires, for example, 600CFM. That 600CFM is spec'd for air removal at the cooktop itself, not at the location of the blower. A remote fan spec'd at 600CFM, after figuring in additional duct length loss and dirty baffle filter restrictions, often pulls about half to two-thirds the air that is required. Now couple in the fact that many "designer" fans rated at 600CFM actually move far less air than that to begin with.Many ducts are not sealed properly as well. I prefer mastic. Messy, but it sure does seal. A remote fan creates a vacuum in the duct, a blower creates pressure in the duct, and a poorly sealed duct can reduce the effectiveness of the fan even more. Visit the Vent-a-Hood site for a basic primer on air movement, ensure with your builder that you're getting an effective setup.Enough already! Viking may suit you just fine and meet all your requirements, but since you're asking questions...Wishing you the best.
*Ditto Mongo's comments.Jeff