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Hood venting and sink frustration - does this sound right?

17 years ago

I am working with a guy from Showplace Cabinets who is putting together a quote for me, and I am going crazy with hood range vent stuff.

First he tried everything under the sun to get me to go with a downdraft range so I could skip the hood altogether.

Once he realized I would not budge on having an externally vented hood, then he was trying to convince me to just pipe it from the hood down through the wall under the house into our crawl space. And on top of it, he says 220 CFM is more than adequate for residential, even going against gravity. From everything I've read here, 220 is NOT enough for anything, let alone enough to push the fumes downward under the house. Plus does a greasy crawlspace sound ideal? Then he got into the topic of the externally mounted fans - anyone know anything about those? Are they expensive? We'd have to mount it externally about 2 feet from the range because the exterior part of the wall starts about 3" to one side of the range - sound possible?

Does the 220 part and venting it downward sound right to you?

He also insists that I need bare min of 6", but much, much preferably more than 9" on the side of my sink in order to allow for granite or really any other countertop. He said nobobody would put even a 5" strip of granite on one side of a farm sink because it can't connect with a supporting strip along front of sink (cause it's a farm sink). Which means we would need to move all the plumbing over about 7 or so inches in order to put in the ss farm sink I want. Does that sound right to you?

Comments (17)

  • 17 years ago

    A lot of people do not care for downdraft drawing power, unless it is a telescopic hood, which can be used only on a deeper than 24" counter because it sits behind the cooktop itself. A telescopic downdraft cannot be used with a range/undercounter oven. to my knowledge because it needs space underneath the counter for the mechanicals.

    Yes, the externally mounted fans are more expensive than many conventional range hoods, but quieter...two feet away however, I am not sure.

    I have a soapstone counter with about 4 inches on one side--they didnt comment upon it when I sent the drawings for estimate. I also have a stone sink, although the sink is mostly supported by a wooden 'crib' underneath.

  • 17 years ago

    The vent hood decision - yikes! I went back and forth and back and forth. Here's my 2 cents...

    Downdraft
    Don't do the downdraft - from what I've read people just aren't very happy with their performance.

    Venting into the crawl space
    This just sounds plain wacky to me (granted I am no expert). What (dare I ask) is his rationale for venting into the crawl space? Depending on where you are located, this may not be code in your jurisdiction (and if this would not be to code, I would verify everything he tells me with at least one other individual....).

    CFMs
    I don't think 220 CFMs would be adequate. Have you told him which stove/cooktop you are using?

    The best way to determine how many CFMs you need is to call the manufacturer of the stove/cooktop and ask them how many CFMs would be needed for their product.

    That is what I did. I am getting a drop-in gas cooktop and although the specs seemed to indicate the unit would fit in a 36" base, they suggested a larger base and I went with that. I also asked if I needed a larger hood than the cooktop and they assured me I would be fine with a 36" hood for their 36" cooktop.

    Externally mounted fan
    I initially considered an externally mounted fan, but decided that if something went wrong it would be a PITA to find someone to climb onto my roof to fix/service the fan. I am going with an internal blower so if something goes wrong it can be serviced from the kitchen.

    Where to locate
    I'm a little confused about where the vent would be located, the location of the stove/cooktop and where it would vent to the roof. Can you post a diagram? The best option is to avoid long runs or bends in the vent pipe (reduces the efficiency of the vent).

    I know nothing about farm sinks and will defer to the many farm sink experts on the forum.

  • 17 years ago

    So this is very rough (and the island design is all changed around - more length added on, no spice cabinet). My free software design trial ran out so I had to use Publisher to add the dining room, but it at least shows the layout and what's going on. You can see there are 2 exterior walls where the exhaust vent for the hood can be mounted. The big question is are there any support beams or studs and where are they? We have a second story on top of this. What's the optimal plan for venting here?

    We are thinking we will likely have to cut a huge huge chunk of drywall out of the dining room side to see what's going on back there before we can finalize any plan.

    {{!gwi}}IMG

    BTW, for the sink, we just decided to move the plumbing over and make almost a foot of countertop on the other side of my sink, which will provide multiple benefits and I think I will really like!

  • 17 years ago

    Many people recommend 1 CFM per 100 BTU max output of your range. Thus if you had 4 15,000 BTU burners, you would want 600 CFM. If you've got a downdraft system, many people recommend adding CFM on top of that, since you're trying to counteract the natural desire of the hot air & smoke to rise. A recommendation of 220 CFM even for an over-the-range hood would be very weak even for a non-professional style range. I have never seen anyone post on gardenweb saying, after their renovation was completed, 'wow I got too many CFM on my hood, I wish I would have gotten less.'

    I have cooked on both regular downdraft systems as well as telescopic downdraft systems. Both were sub-par in my opinion and I would never recommend them if you are a somewhat serious cook, or even an occasional cook.

    Venting into a crawlspace/attic is a horrible idea. All of the moisture will cause terrible problems, rot, mold, not to mention the grease that will accumulate under there. Imagine the little mini-ecosystem you will create with parasites, insects, and fungi with all of that moisture and grease. Please do NOT do that. It is also likely not permissible under your local building code. I would check the BOCA 99 or newer building code, which your municipality has likely adopted.

    Have you considered moving your range over to the right, and venting directly out and behind the range, using an internal blower ~600cfm? That would be a much better option.

    Downdrafts are only used for aesthetic purposes. If your kitchen is going to be a working kitchen then you should seriously consider a normal over-the-range hood.

  • 17 years ago

    I could move it 20" to the right without negatively impacting functionality. Behind the table is quite cramped (less than 2' walkway) so I can't move more than 20".

    If I did move it the 20", the right edge of the range would sit 13" past the interior-side start of the dining room wall.

    That would place the middle of the hood probably right square over the T where all the walls meet - ack!

    So it should probably stay where it is or really close to that!

    Does piping along back range wall out to the kitchen window wall sound best? Two contractors who have been here say it won't be possible due to the walls T-ing through that path.

  • 17 years ago

    Even if you do downdraft, it needs to be vented outside! They aren't the best for ventilation, but they are far far better than nothing.

    You don't have far to go to get it outside. I'd get a proper hood and accept the bends required to vent it out. The appliance forum will tell you everything you need to know about hoods...and more!

    All I can say is, do NOT take anything this guy says as correct without triple checking it. Anyone who wants to vent into a crawl space is unqualified. He's making things up (or he hates you). :)

  • 17 years ago

    Is there a soffit above the cabinets?

    Straight up to the ceiling bend right, through the soffit and out the end wall over the refrigerator or bend out through the wall next to the refrigerator. If there is no soffit, perhaps you can go right through the cabinets along the top shelf in the back, not ideal but I've seen it done.
    Its all nonstructural to the house except the hole for the vent cap.

    I live in a condominium and there are FIVE vent pipes running through my soffit from various kitchens and baths below me and my own :-)

  • 17 years ago

    We have no soffit above the cabinets and won't have them in our new cabinets going in.

    We will most definately go with a proper hood and venting to the outside especially with the input I've gotten here. That was what I wanted to do from the first, it's just gotten bucked at every turn from the people coming over for estimates on cabinets. I don't know why they are all so anti-hood, anti-venting.

    I will post this in the appliance forum to see if they have any ideas of how to at least get started with mapping out a plan, identifying ideal scenarios for venting, and what I need to do to uncover which scenario will work.

  • 17 years ago

    You said you have another story above you - what is directly above the area where the stove is located? You could vent straight up, creating an area for the necessary vent pipe (with any luck there is a closet above the stove and you would only lose a small amount of space).

    Or vent up, go into the dining room (creating a soffit) run along that wall to vent outside. That might be the easiest way to do this without moving the stove to another location (which doesn't seem like it would work for you).

    Best of luck and let us know what you decide to do.

  • 17 years ago

    Does no soffit mean the cabinets extend all the way to the ceiling or does it mean that you are having a space between the top of the cabinets and the ceiling.

    If you are keeping an open space up there you may still be able to squeeze duct up there depending on the size and get it past that corner and out the wall, and hide it by using a moulding on the front edge of the cabinets or drywall against the duct toward the back that would still give the illusion of space.

    I am not a fan of the open space above cabinets. I think this was popularized by builders who didnt want to have to build soffits and compensate for off level ceilings versus the level tops of cabinets.

  • 17 years ago

    You guys are fabulous - I got so stuck into the thinking that it had to be in the wall, I missed these other venting options.

    I just realized there is a very good chance that the wall ends up being one that goes up right though the master bedroom closet wall on the second story. That's a possibility! But then it's scary cutting the roof to ensure no leaks!

    Our new cabinets will be staggered with most of it going to the ceiling. It could potentially be worked around behind moulding - it would just have to go through the hutch somehow and the mullion doors may complicate it, but I am leaning toward custom since their prices are coming in exactly the same as semi-custom, and that could then be built in somehow - any idea how to hide the ducting through the hutch?

    Here is the plan from the bid that comes the closest to what I am envisioning:

    {{!gwi}}

  • 17 years ago

    Ug nobody responded at all!

    OK, so no ducting input - that's really OK, I think I got a handle on it, but does anyone have any input on this design? Does it look OK?

    I discovered the Sharp slide in range with the oven and drawer microwave built in together under the smooth ceramic cooktop. That's the one I will be putting in.

    I will also be making the island bigger and adding about 11" of countertop to the skinny side of the sink.

    And I don't think I will have fluting along the left side of the run of the cabinets.

    Does it look OK? Anything you see right away that needs to be changed?

  • 17 years ago

    Do you have a 2D version of your layout with measurements? That would help with providing input regarding your layout. You mention making the island 11 inches wider on the skinny side of the sink - how close is that side of the island to the wall?

  • 17 years ago

    Have you considered moving the hutch area with the open shelving to the very far left side of the wall that it is currently on? This might make more sense, as it will be closer to the formal dining room. This would allow you to move your range over to the right, and allowing more room for proper venting.

    Have you considered making your dining room table a part of your island? Like...making it a lower section? That will help to make more continuity, and will allow you to introduce a new material. It seems to be a new trend in kitchen design and it looks really sharp.

  • 17 years ago

    People vent their hoods through the roof all of time so you shouldn't have a problem if it's done correctly. You may want to post your two dimensional layout in a new thread. You'll get a lot more responses that way. Good luck.

  • 17 years ago

    Wow, Kev 800, you have some ideas I hadn't even thought about at all, and ones I will have to think on. If I did move that hutch, I would have no choice but to turn the island into an island/table combo because there is very, very little manuver space (like This design isn't a final, it was drawn up as part of a bid so I don't have the measurements, but once I choose a company and get measured plans, I do plan on posting for feedback. There is 44" between the wall and the island, but we would move the sink and dishwasher to the left and put a 9" cabinet to the right of the sink to allow for that countertop. In the end, I think I will take up an inch and have that walkway be 43".

  • 17 years ago

    I think it looks good at first glance, but Cheri's right about a new thread if you haven't already.

    Are you sure you're okay with no space on one side of the sink?