There are numbers of recent discussions of range hoods and a search will turn up a lot of helpful information. Besides recommending that you search for those threads, I'll just make a few suggestions here.

1. The reason Kobe told you that a 600 CFM hood will not be sufficient is this generally acepted rule of thumb: for high-btu stoves, figure 1 CFM of fan capacity for each 100 btu-hr capacity of the stove. If you have all six 15k BTU-hr burners running on max (90,000 BTU-hr gas consumption) AND you have the oven going as hot as it will get (20,000 BTU-hr), that totals 110,000 btu-hr of gas being burned. Do the arithmetic and you get a need for a 1120 cfm hood. If you look only at the cooktop output, your NXR still is capable of burning 90,000 BTU-hrs of gas, which translates to a 900 CFM range hood.

This rule of thumb was developed for commercial kitchens where they might very well be running, say, three woks or three saute pans at max heat while also boiling three pots of pasta water.

If you do not plan on putting on that kind of show, then a 600 or 700 CFM Kobe hood probably will work okay.

I'm using a 600 CFM hood with my 30-inch NXR which is theoretically the minimum for my four-burner stove. I have yet to overwhelm it. But, then, I do not simultaneously run all four 15k-BTU-hr burners on max, searing steaks and boiling pasta water while running the convection oven at 500 F.

2. If you already have 7-inch ducting, that can expand your choices of hoods. My recollection is that most 600 CFM hoods use 6-inch round ducts and/or 3"x10" rectangular ductings. The difficulty with going for larger hoods is that many of them require 8" or larger ducting being recommended. In theory, you can reduce down to a smaller size but it affects efficiency and tends to diminish the air-flow capacity.

3. Kobe hoods are generally pretty well thought of here at GW. (As always, do a search).

4. This leads to another rule of thumb. A big deal with rangehoods is "capture area." Units that are actual hoods (as opposed to flat-bottomed venting units) will do a better job at capturing and containing smoke, steam and other vapors. Even with canopy-type hoods, there is still a suggestion to get a hood that is the next larger width than your stove. That is, you get a 36-inch hood for a 30" stove, a 42" hood for a 36-inch stove, etc. But, if you are constrained by cabinets, then a 36" hood will have to do.

5. For an interesting example of a 700 cfm Kobe hood with a 36" NXR, check out this link, which is an article from the 2011 Fine Homebuilding annual edition on kitchens and baths.

http://www.nerland.net/wp-content/uploads/2012/02/Fine-Homebuilding-Kitchen-article-Issue-223.pdf

6. Finally, a couple of related points.

(a) In the couple of months that I've had my NXR, I've found that those 15k-btu-hr burners work better in high-heat applications with larger pans (at least 10 inches in diameter and preferably 12-inches or greater). With the larger pans, there seems to be less waste heat in the kitchen (that is, the large pans do a better job of capturing more of the heat.) However, there is a trade-off: more vapors and goo come off the surface of the pan, which means that there is more of that to be collected by the range hood (and more to be cleaned off the stove.) That inevitably means that the hood needs more frequent cleaning. So, consider cleanability in your choice of hood as well as having grease traps that will minimize the amount of grease that gets past the hood to your ducting. My recollection is that Kobe hoods have a pretty good reputation in that regard.

(b) The NXR oven vents out the backsplash. It can get pretty hot back there on standard bake. Virtually any range hood can take care of that heat. It is a different story when you run the convection fan. (This is likely true of almost every gas convection stove.) Unless you enjoy hot-house temps in your kitchen, you definitely want a good range hood to help evacuate that heat.

6. There is another, subtler reason to consider a larger-capacity range hood. Lower noise. A bigger and more powerful hood can move the same amount of air at lower motor speeds. Lower motor speeds generally means less machine noise.

7. Finally, remember to check on the need for make-up air. Even a 600 CFM hood moves a pretty fair amount of air. That air has to come from somewhere in the house. Make-up air can be simple or complicated depending on your situation and you local building regulations. Numbers of cities and some states are now prescribing requirements for make-up air. In some places, it may be enough to provide direct MUA for appliances that could backdraft (say, water heaters and gas furnaces). Check into this.

JWVideo,

Thank you for this information. I had know idea there would be so much going into being able to have this range.

Are you happy with your NXR? I have read a couple of reviews on here but I don't know if one was yours. I keep wondering if I should just go with the 30", would it be easier (hood and make-up air wise). One of the the reason I was wanting to go to the 36" is because I enjoy cooking and tend to use lots of pots. I get frustrated with having to try to fit pans and then shifting them around. I figured a 36" would help me with that. I don't think I would ever have more then 4 burners going at a time but I could have them going with the oven. I was thinking it would be nice to have the griddle in the center but Costco doesn't seem to sell that one. I am assuming I will not be able to use the smaller sauce pans with this stove then. I was looking at hoods with baffle filters, which I think are suppose to be easier to clean. Is your hood a 36"? I was planning a 36" hood not larger but I could go larger if I really needed. If I can get away with a higher cfm and keep it 36" for me that would be better.
I have never heard of Make-up air, where do I go to check on this? I certainly do not want a dangerous situation happening. Who do I contact about this to know? Was this something you had to do with the 30"?

Thanks so much!

IMHO a 600 CFM hood should be sufficient - hood manufacturers want to oversell you. Get a deep hood, though, at least 24" deep.

If you have a tight house, a powerful hood can suck the air out and cuase backdrafting of furnaces, etc., hence the need for some kind of makeup air. Until recently, local code did not require makeup for 600 CFMs or less except in very cold climates. Recently with the prevalence of pro-style ranges, more locales are lowering the CFM level that require makeup air. The first thing you need to do is check with your local building dept. to see what code is in your area.

Weissman,
Thank you, I called and left a message for the building department. Hopefully I will get a call back sooner rather then later. I am not sure if I have a tight house or not but every now and then I will feel a draft. If code is still 600cfm's, am I to assume it would be okay to install? I am assuming if the code is above 400 cfm's then I may need to rethink my range. Would the cfm's matter if I decide to go with the 30" range? Could I use 400cfms for that? In my reading thus far, it seems adding MUA is expensive. I did see from an article that Broan has a make-up air damper that is suppose to help with this. They have two size 6" and 8", but my duct is 7" so, that is an issue. I guess I just have to wait till I hear from the city. Thanks again!

To find out if your house is drafty or tight, you should get an energy audit which includes putting a blower at an exterior door and measuring pressure build up. A lot of utility companies offer this as a free service.

MUA might not be expensive. If you live in a warm climate, say Florida, your windows will be your MUA system. It really varies with the situation and the local codes and the local regulators. I have a 102 year-old house that I have really tightened up. I built some simple MUA devices in the basement for my power-vented water heater, the clothes dryer and the auxillary floor furnace. (My main heat is hot water radiant floor tubing supplied by a water heater). The MUA devices are basically reverse snorkels with a bucket-like trap so the air gets warmed before flowing out into the basement. I made them out of 3" and 4" PVC piping that goes into the basement next to the appliances. A lot of folks in my mountain town use similar devices for feeding air to wood stoves as well as for supplying MUA for radon removal fans. (We're a coal mining region so a lot of basements need fans to keep interior radon levels low.)

According my energy audit, my system is plenty sufficent for supplying the MUA needs for those appliances and my range hood. It does keep the basement coolish in the winter, but that's fine for me as I'm storing vegetables, making pickles and curing meat down there, anyway. The cost of my system was about $20 worth of PVC pipes.

There are other ways to do this and they can get progressively more expensive up to the commercial installations which involve blowers, backdraft protection and fire suppression systems. If you have a particularly tight newly constructed house, you might already have a MUA system that has a heat exchanger.

Local codes on this vary. Many towns have no rules on this. I've read here that some cities in Minnesota impose the MUA requirements for hoods that draw over 400 CFM. Do a search on MUA and you've find numbers of informative discussions of this subject.

As for getting a 36" NXR, I'd say, get what you want. Alex Nerland, whose kitchen is in the Fine Homebuilding article, seems to like his. I have a couple of friends, also in the Bay Area, who have one, and they like it.

>>>"I have read a couple of reviews on here but I don't know if one was yours"I am one of several dozen folks who have posted here about their NXRs and you probably have seen some of my comments.

>>>" One of the the reason I was wanting to go to the 36" is because I enjoy cooking and tend to use lots of pots. I get frustrated with having to try to fit pans and then shifting them around. I figured a 36" would help me with that." Have you actually compared a 36 inch stove with a 30 inch? Most pro-style stoves have similar burner spacings. If you can find a store that has, say, DCS, Wolf, Viking or Blue Stars on the floor, take some of your pans and go check them out. On my 30" NXR, I've had a 13" diameter canning kettle, an 20 quart stock pot, a dutch oven and 12" diameter fry pan all going at once. The 30" has a roughly six-inch wide panel down the middle, which means the right side and left side burners are about 17 inches on center. Front burners are roughly 11 inches on center from the back burners. With a 36 inch stove, the burners will be roughly the same distance apart right to left as front to back. If you put some pots on a 36" stove top, you can see if there's enough room for you to move pots around the way you want to. Or maybe find out that it will not make any difference to you. There is no right answer for this question. It really is personal preference. You either will like it or you won't.

>>>"I was thinking it would be nice to have the griddle in the center but Costco doesn't seem to sell that one."My personal take is that a separate griddle is more convenient and easier to clean, too. Have you seen Nunyabiz1's photos of his? He bought a ChefKing which is carbon steel and 14"x23" and works great on his 30" NXR. My Bay Area friends have had one for three years that they got for one their 36" NXR.

>>>"I am assuming I will not be able to use the smaller sauce pans with this stove then."Not so. I've had no problem with small sauce pans. Boiling water for oatmeal, making small quantities of soup, melting chocolate, making cream suaces/graviews, etc. --- anything with low to medium high heat is fine. Small pans are only a problem on the NXR (and most pro-style stoves for that matter) when you want to use very high heat with a small pan. When burners are large relative to the pan, on full blast, a lot of heat is going around the pan. But, then, how often do you plan on, say, searing shrimp at 500 F in a tiny pan? Do you want to try wokking in a 5" diameter sauce pan? Not me.

>>>"I was looking at hoods with baffle filters, which I think are suppose to be easier to clean. Is your hood a 36"?"

Yes. About ten years ago, I got a 36" Zephyr Cyclone because it was only 5-inches high and my small kitchen has space constraints. It uses twin fans with grease separators which drain into easily removed catch basins and the set-up works pretty well. When I reworked the cabinetry last winter, I found very little grease build up in the ducting.

>>>"If I can get away with a higher cfm and keep it 36" for me that would be better."We work with the space we have. I referred to the design rules as "rules of thumb" because they are only generic guidelines not mandatory requirements. A 36 inch hood will work.

>>>"Would the cfm's matter if I decide to go with the 30" range? Could I use 400cfms for that?"Sure. Nunyabiz and a couple of others have posted about using 400 CFM Over the Range (OTR) microwave/vents with their 30" NXR stoves. Not ideal but it can work. Better to go with that Kobe you were looking at even if you only get a 30" NXR.

>>>"I did see from an article that Broan has a make-up air damper that is suppose to help with this. They have two size 6" and 8", but my duct is 7" so, that is an issue."I do not have first hand experience with that Broan damper unit but I am pretty sure that it goes in its own separate duct. You do not have to match it to the range hood dyucting does not go in the range hood's vent ducting. A six inch diameter intake will provide plenty of MUA for a range hood with a seven inch vent duct. The incoming air will just make more noise rushing in through it's own duct, My recollection is that you want it to come out to a register in the wall within five feet of your range hood. I believe that Broan specs (and maybe supplies) a register which will look like a heating vent or cold-air return. The motor on the damper is wired to the switch on your hood.

But, that might not be necsssary. As discussed above, you may be able to provide MUA to the venting appliances elsewhere in the home or use some other solution. Or, you might not need it if you have a really leaky house. I'd say, do check with the city but also see about that energy audit.

JW pretty much covered it.

I would highly recommend the 14x23" Chef King griddle though as JW mentioned, I use it every single day, more than any other pan I own.
If you do not need your microwave or have counter space for one elsewhere then ideally I would go with a 900+cfm hood for a 36" and 600+cfm for the 30".

I use 400cfm OTR micro/hood on my 30" and it works fine 95 percent of the time, only if I am at full blaze with the griddle and the other burners going does it start to get overwhelmed.

JW Video, thank you so much for taking the time to leave such detailed replies. I spoke with a local HVAC person and he said given the age of my house, I wouldn't have a tight house and that I would be fine. He also said if I was concerned to just open a window. I am assuming this is what you meant about the windows being my MUA. I live in So. Cal so I suppose it is a bit of a warmer climate. I haven't heard back from the city about code though. I did see Nunyabiz1's pictures while I was researching the NXR. I will have to look into that griddle. I was thinking it would probably be difficult to clean an attached one. I think I am going to stick with the 36" range. I looked at the article you posted. It was a beautiful kitchen and the NXR look so nice. The spot where mine is going is slight bigger, so I don't think it will overwhelm my kitchen. While doing my research I had noticed a post on here that was talking about the change of the stainless steel from 304 to 430. I called DuroCorp and asked them about it. They answered the phone right away, no automated voice. I as transfered to the "Range" person, and talked to him about the range. He told me that the first model's were constructed of all 304 stainless steel. He said that the range doors and side panels are now the 430 but the top remains 304. The reason for the change was to allow them to keep the range at the reasonable price point. I had only seen those comment on it be changed but not that it was a combination of the two steels. He talked about the parts being from Germany and such. I also asked him about parts, whether they have stock here or do they come from China. He said the the warranty company should have parts but I could always call them directly because they have parts too. I don't know whether that is entirely true, but none the less I was happy with the willingness to anwser my questions.

One last thing, I can't find a 22" depth range hood in my price. They all seem to be $500 more. I really don't want to increase my spending. That and the ducting on the bigger depths would not work for me, so it looks like a 22" depth is my only option.

Nunyabiz1, I would love to know all the wonderful things you cook on your griddle. I saw one of your pictures where you were frying up some eggs, so yummy!

Thanks again for all your help!

It sounds like you could use a little reassurance on the subject of parts.

Apart from the oven door and maybe the stovetop grates --- things that are pretty hard to damage and unlikely to fail --- NXR components are all things used on other stoves. Therefore, I don't care if they do or do not have a company stockpile because the components are readily available from local appliance parts supply warehouses. Have you run across the postings here by StacyNeil and DirtyBloomers on replacing the oven ignitor/glowbar. Turns out that this is a $15 part that is also used on GE, Frigidaire, Whirlpool and other gas stoves.

My inner chronic old fart says that it is a crying shame we have to pay so much money for simple, durable, good performing appliances like we used to have in the so-called old days. The reality is that the NXRs are old-fashioned designs --- excuse me, mature technology. The company skipped propietary electronic controller boards and those kinds of parts. There is not much that can go wrong and what does fail can be fixed with readily available off-the-shelf components.

Feeling reassured?

The beauty of NXR is that all you need for venting is an OTR microwave.

Yes, thank you! I am very excited about this range. I am looking forward to having my kitchen completed and cooking my first meal with it.

What "don't" I cook on my griddle would be a shorter list.

Obviously breakfast, hash browns, eggs of all kinds but it is especially good for omelets cooked short order style where you put a few chopped onions, bell pepper etc on griddle with a little butter until they are translucent pinch of kosher salt and a few cracks of fresh pepper then take 5-6 eggs scrambled well in a bowl spread the onions and peppers out the length of the griddle then pour the eggs down the length of griddle then a handful of shredded cheese on top. By the time you put the bowl down it is time to start flipping the omelet from the rear towards the front, just slide spatula under it and flip over & over, let it sit about 1 minute and its done, cut in 3 pieces.
Perfect for pancakes.

Great for burgers, hot dogs plus the buns.
Panini's just use the bottom of a 12" cast iron skillet as the press and heat the skillet on the other burner before you press, browns both sides at once.

Good for everything you do with a frying pan except gravy.

It is like having a miniature restaurant flattop in your kitchen and you just remove it when you need the burners for something else.
It is totally nonstick and only gets better with age.

Nunyabiz1, wow all that sounds so yummy! Wouldn't it be great if all I had to do was own that griddle to be an amazing cook! Well, you have certainly convinced me to get that and I love the technique for the panini's! I will report back in late January about how my first omelet goes.

I am sure you will like it, make sure you get the "14"x 23" 7 gauge" NOT the 12x20.

I bought mine for 51.78 on Amazon with free shipping, although right now they are selling them for 71.17 on Amazon.
dvorsons has them for 69.00.
So around 70.00 seems to be about best price currently.

I just got off the phone with the person from the city and he said I was fine regarding make-up air. He also said the windows act as the make-up air. So I feel much better now. I will make sure to get the 14" x 24" griddle. Thanks again for everyone's input!

So does anyone else have experience using an OTR microwave to vent the 36inch NXR gas range?