Question On Wall Material Behind And Above Range

jyl · jyl's Garage

Looking for some advice.

See the sketch above. The wall behind the range would be vertical for about 24", then begin to curve inward, a "barrel" shape, with the top of the curve about 48" above the range burners and overhanging those burners. The curve will lead to the vent hood.

If the wall is wood framing, covered with two layers of Durock (concrete board), covered with ceramic tile, would that pose a fire hazard or be a code violation, do you think?

The range's installation instructions say that combustible material directly above the range must be 30" from the cooking surface, and non-combustible material must be 24".

(The ducting for the vent runs in the pushed-out area of the wall.)

rwest · rwest's Garage

I would think that the dura rock and tile would protect the wood, but why not use the heavier gauge steel studs in this area instead?

fintstone · fintstone's Garage

It appears that your design has the hood only above the front half the cooktop and extending far past where it would do nothing. It does not make a lot of sense to do it that way to me. Why not eliminate the curve and place the proper sized hood directly over the cooktop?

The hood would extend into the area where a person would stand when working. Although a person would have to be 7' to hit their head, it might seem a bit close for a tall person. Especially when the fan is on.

The curved part would always be dirty...so it needs to be an easily cleaned material.

look 171 · 03-19-2016, 09:36 AM

John,

Any way to vent it up ward instead of creating the bump out? Reason? Wall should be fine with dual layer of cement board. Are you concern about the wall in the curve section?

If you are really concern and want to get fancy, angle the studs and flow a bed of concrete onto the curve section making it flush with the vertical wall, apply tile or SS panel as the finish surface. With the big-o-bumpout, you need to wear a helmet every time you cook. The bottom of the hood will be only 5'-6" from the finish floor. Reaching to the back burners will be a challenge unless you have arms that are longer then 3'.

HardDrive · 03-19-2016, 11:22 AM

This is very poor idea for many reasons, not the least of which being that the vent will be totally ineffective because its too far off the cooking surface. Regardless of the material used on the curved section, it will be constantly coated with cooking grease and difficult to clean. Tile would be a nightmare.

We had a similar situation in our kitchen. I built a soffit that ran the entire length of the wall on that end of the room, and hid the ducting in the soffit. Our friends in Seattle (by chance we are flying there tomorrow) had the same issue, and elected to have nice a nice stainless shroud that covers the ducting fabricated. It looks great. I'll snap a photo tomorrow night if you like.

HardDrive · 03-19-2016, 11:36 AM

Ours is still in progress. Its a Wolf hood. Currently covered in paper to protect it while I paint. There is a shroud that covers the ducting from the hood to the ceiling. The ducting runs through the soffit to the left.

Charles Freeborn · Charles Freeborn's Garage

The more distance from the range the bigger the fan you'll need. Consider a roof or exterior wall mount blower. That way your neighbors will listen to it not you.
As for wall material looks like a good place for Stainless Steel sheet. Can be backed by cutting the curved sections from plywood and laminate together to make the "studs". Then skin with multiple layers of thin bendable plywood on the curved section.

-C

jyl · jyl's Garage

Hmm, good points everyone.

Right now there are upper cabinets on the range wall, and the vent duct horizontal run is in those upper cabinets. I could build a soffit. That would be easier than going up into the ceiling.

Oh, wait. On the other side of the range wall is the stairwell going down into the basement and side door. I could simply run the ducting exposed in the stairwell.

I like the idea of a high hood, that is much deeper and wider than the range. My thought is that the larger hood will capture dirty rising air, using coverage instead of a very big CFM fan. For the combined BTU of my range burners, standard guides say I need a 1400 CFM vent fan and a makeup air system. I'm trying to find a way to avoid that big a vent/makeup air system.

I'd also like to be able to stand under the hood instead of bumping my head against the hood. You know how commercial kitchens are set up, with the big hoods extending past the edge of the range, over the cook's head.

HardDrive · 03-19-2016, 02:59 PM

Quote:

Originally Posted by jyl

I like the idea of a high hood, that is much deeper and wider than the range. My thought is that the larger hood will capture dirty rising air, using coverage instead of a very big CFM fan. For the combined BTU of my range burners, standard guides say I need a 1400 CFM vent fan and a makeup air system. I'm trying to find a way to avoid that big a vent/makeup air system.

I'd also like to be able to stand under the hood instead of bumping my head against the hood. You know how commercial kitchens are set up, with the big hoods extending past the edge of the range, over the cook's head.

Commercial kitchens indeed have a vent that is high off the cooking surface. That's because they have fans that are often 24,000cfm+!

I'm not going to belabor this, but you really need to do more homework. Trust me, I've built out 3 homes with vent systems in the past 5 years. Air does not flow in the way you are envisioning.

jyl · jyl's Garage

Have you put makeup air in any of your houses?

It sounds like such a pain, and expense. I'm really trying to avoid it.

HardDrive · 03-19-2016, 04:39 PM

Quote:

Originally Posted by jyl

Have you put makeup air in any of your houses?

It sounds like such a pain, and expense. I'm really trying to avoid it.

No, but I'm going to need it in the current house. We have an extension on our kitchen that we built before we bought it. They didn't use sealed can lights, and during the winter, when you turn the vent on, cold air pours in through the lights. Sucks!

Our house in Seattle did not need it. In the PNW you can probably avoid it.

jyl · jyl's Garage

I'm using this design guide.

http://www.greenheck.com/media/pdf/otherinfo/KVSApplDesign_catalog.pdf

Seems very comprehensive. But it is for commercial systems. My range has total 140K BTU burners plus the oven. When I calculate the CFM required using this method, I get about 1000 CFM (don't have exact number handy). I think I can get away without MUA at that CFM level, because I have an old, leaky house. Anyway I think I can add MUA later if needed.

This guide assumes commercial equipment, meaning hoods above head height and large enough to overhang the cooking appliance. I don't have any reason to think the guide works for residential equipment, where the hood is smaller than the appliance but is placed lower.

Problem is, wife objects to the look of something like
https://www.acitydiscount.com/Superior-Hoods-7Ft-Stainless-Steel-Restaurant-Range-Grease-Hood-NSF-NFPA96-VSE42-7.0.27035.1.1.htm

I don't understand why. We paid a bunch for a "commercial-look" range, and we have a commercial refrigerator, so why won't she permit a commercial exhaust hood? We continue to negotiate.

HardDrive · 03-19-2016, 05:08 PM

How wide is the range? That hood is 7 ft wide. Looks like over kill.

wdfifteen · wdfifteen's Garage

Have you sourced a shallow hood like the one you show? I don't think I've ever seen one like that.
I have multi speed fans in the vent I installed. I seldom need to crank them up, but when I do I crack a window.

look 171 · 03-19-2016, 05:17 PM

I run into foodies who rreally like to cook and they have some weird requests over the years. I have to continue this simple reminder, its a house not a commercial kitchen. I am a big fan of 42" commercial looking residential hoods like Wolf, and such (with an external blower like Charles suggested. They are not that loud so your neighbor will not give you the dagger eye) for 36" range or cook tops. 30" is the typ dimension between hood and cook top. In your situation, you will bump your head on the edge of the hood with it sitting on front of the soffit. Is there a reason why you don't want to run the vent up through the roof? Is this a complete remodel?

I really don't need make up air. 1200 CFM is pretty good air float. That's what I have in my own house and my home is sealed up pretty good. We always crack open a window come cooking even if its raining. The big overhang help keep the rain off the window.

jyl · jyl's Garage

There's a second floor above. I need to turn the air 90 degrees and go out the exterior wall, which is only about 6 feet away. It will be easy to do it in a soffit, on in the stairwell I mentioned.

look 171 · 03-19-2016, 07:29 PM

Oh. 1200 CFM requires a 8" duct if I remembered correctly, maybe 10"? How tall is that hood? You should be able to sneak a 90 degree elbow up there coming out of the top of the range then onto the exterior. For most hood, there should be enough room. On a commercial hood, then its a difference story? I am not sure if there are any benefit by going that way but price. Commercial hood=inferior SS finish, loud and no sound restriction. They just work and remove air and usually bulky.

HardDrive · 03-19-2016, 08:06 PM

If you decide to go custom, Vent-a-hood are the gurus.

Vent-A-Hood | Your Dream Starts Here

VincentVega · 03-19-2016, 08:50 PM

This brings back memories. I put a 42" Zephr undercabinet hood over a 36" 6 burner Blue Star. Couldnt be happier. Stock is 650 cfm and you can add another blower for 1200 if required. I figured I would try as is and so far I dont need it. I think it really depends on how/what you cook. I can sear 2 steaks in a smoking hot pan and the hood keeps up. I never sear steaks on all the burners at once or use 3 wok's at a time, maybe you do.

I played with height a bit too. I ended up mocking one up with cardboard and kept raising it up until I didnt hit my head when reaching to the back burners, real scientigic. I'm ~6'3 and at 30" over the range it would smack me in the head, that would get old quick. I think the guides are just that, nothing is in stone. Maybe I have to use speed 2 now instead of 1 because its a little higher, that doesnt bother me at all.