How much CFM does a grill really need?

acertainJune 7, 2012

We're looking at the 36" Bluestar with a grill and are trying to plan the hood. We're trying to balance the MUA needs with the needs of getting rid of the smoke, etc.

My wife, upon hearing about MUA, has decided that the grill is not worth it, so I'm trying to figure out what our needs really are so that I can still get what I want... :)

My first question is whether anybody with a grilltop (whether BS, Capitol, Wolf or whatever) has a hood and is disappointed with the smoke-pulling ability of the hood. If so, what's the brand and CFM of your unit?

Second, if you have a grill and an Thanks.


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Andrew - venting is the main reason I gave up on BS. I was interested in the rangetop with grill, but the BS rep told me I would need 1200cfm or more. Without the grill, i.e. the 6 burner rangetop or 5 burner cooktop would need minimum of 900cfm. I switched to induction instead.

Sorry if this isn't what you wanted to hear.


    Bookmark   June 7, 2012 at 9:17AM
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I understand what people tell you you need. I'm interested in what people actually are using. Does anybody have experience with the grill and insufficient ventilation or a Andrew

    Bookmark   June 7, 2012 at 10:30AM
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I use a Bluestar range without any venting and it works fine 95% of the time just as the old range worked fine without any venting. Grilling fatty meat on a grill pan is when venting would be a good idea. I open the window and use a small window fan in those cases.

It's been discussed before, but a large capture area over the range is probably as important as the CFM's .

I find it humorous that someone thinks that searing a couple burgers with induction will produce less smoke than cooking on gas. Less heat in the kitchen yes, less smoke, no...Certainly someone with induction can burn butter in a frying pan? Or cook bacon, or smell the garlic and onions?

Really, be reasonable. Cooking produces mainly moisture, odors, if food smells, not a bad thing- they say that taste is related to smell, and smoke if you burn your food or cook greasy meats. Smoke is by far the most annoying and the one thing you want to get rid of as soon as possible- while you're cooking. Odors and moisture can be removed by running your fan longer...

    Bookmark   June 7, 2012 at 11:42AM
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I used an indoor grill with a 600 cfm fan for 8 years without problems. On a bad flare up some smoke made it into the kitchen, but it was no big deal. Don't forget that everything is perfect on the Internet. We are all tall, thin, in great shape and make a trillion dollars a year to afford to handle any problems that come our way. In reality sometimes things don't work perfectly. Now I have a 1200 cfm fan with my CC 48 with grill and griddle. It works flawlessly but I have no make up air, but I do have a window and I crack it open when the fan is on anything other than low.

Whatever you do make sure you go for the grill. It is hands down the best feature in my kitchen. Everyone I know who has one loves it.

    Bookmark   June 7, 2012 at 12:02PM
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Have Wolf charbroiler on 36" AG range with 600 cfm VH, 27"X42" and a short duct run with a gradual 90 degree turn. Cabinets flank both sides of the hood which probably help. Works fine just about all the time; completely agree with Emilner's post above.

    Bookmark   June 8, 2012 at 12:46PM
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We are new owners of a 36" bluestar with charbroiler. Our vent is a Best PIK45 insert with custom hood. We have an external mount 1500 CFM Best blower. The vent run is about 8 feet with a couple of bends via a 10 inch pipe. The charbroiler has not required more than 50% fan speed thus far. We have grilled pork chops, lamb and steaks thus far. Nothing too fatty. The times I have been glad to have 1500 CFM have been when woking on the 22k burner (amazing amounts of smoke!!). The cost differential between 900 and 1500 CFM was not that much in our assessment so we went with the highest CFM we could get.

The whole MUA thing is mystifying to me. Open a window. We have a 2000 square foot ground floor with an open floor plan and 24 foot high ceilings in part, so there is a lot of airspace, but even still, I fail to understand why opening a window (a crack in window) is an inadequate strategy for MUA.

    Bookmark   June 8, 2012 at 10:22PM
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"The whole MUA thing is mystifying to me. Open a window."

Excuse me, but there are huge numbers of people who live in climates where it gets COLD. As in FREEZING COLD. Besides the three months per year when our windows are frozen shut, there are another three-four months or more when it is still cold enough that we don't appreciate a blast of outdoor air up our backsides when we are cooking. Many of us cannot contemplate grilling indoors, especially in winter, due to the cost of ventilation and MUA. But it's not like grilling is a necessity of life - we manage to feed ourselves using less messy techniques.

    Bookmark   June 9, 2012 at 12:54AM
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Following cooksnsews: locales where MUA is required by code and enforced, opening a window does not suffice.

    Bookmark   June 9, 2012 at 2:51AM
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My setup is a 48" Blue Star with a 900 CFM, 54" Vent-a-Hood. In the six years of woking and grilling, I have never has an issue with smoke in the house. I also has the builder mount the hood several inches higher than the manufacturer's recommendation because it was too low and I expected to constantly bump my head on the darn thing. It's performed like a champ.

    Bookmark   June 12, 2012 at 5:09AM
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I live in cold Minnesota in a 100 year old house that certainly isn't air tight. If we were to get a 36" range--Bluestar or American Range-- with a grill feature, would we be okay with just the range hood that is recommended for a regular 36" range without a grill? We do not have space for any wider than 36" wide for a hood. We also do not want to get into the makeup air game, and we have a boiler for a furnace and we don't have cental air. We'd just be using the grill for the two of us, we don't typically eat huge slabs of meat, and we don't mind cracking a window if we have to.

So many of these recommendations I've read as far as what is perfect just aren't reality for most of us who have space constraints, older houses, pockets that aren't unlimited etc. I should also add in here that we are replacing a 20 year old JennAir downdraft that we sometimes grill on in the winter. The smoke alarm has sometimes gone off, but we have lived with it and without having any range hood at all for all of these years, so we certainly aren't looking for perfection here. We are looking for simple and relatively functional. Thanks.

    Bookmark   January 19, 2013 at 12:11AM
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There are multiple issues with hood cfm and MUA requirements that need to be addressed, including:

Safety is dependent on whether the fan at full power with windows however you will open them without fail causes the house pressure to fall below about 0.03 inches of water; but(!), this is only an issue if there are combustion appliances that can be back-drafted by the pressure drop or if there is an operating open fireplace.

A cracked window is going to provide only modest MUA cfm at low pressure drop. A wide open window (with screen) is needed for larger capacity ventilation if the pressure is to stay below the threshold of back-drafting.

Restricted MUA causes a pressure drop which in turn reduces the capacity of the ventilation system. There is always MUA for whatever flow rate the hood actually achieves.

For part of the year in most of the USA and Canada, the outside temperature is low enough that normal household room heating capacity (BTU/hr/room with window open) will not be sufficient for the larger ventilation fan capabilities. This means that it will get cold inside for the duration of grilling or wokking unless a blower supported MUA system is used with a heat exchanger.

To keep rising effluent from curling out of the hood due to its momentum and "reflections" in the internal hood geometry, it is necessary for the air velocity established by the exhaust fan in the vicinity of the baffles (or in mesh hoods at the bottom) to equal the velocity of the rising cooking effluent. Because the fan air velocity will be about the same over the entire critical area, the flow rate (cfm) has to be about equal to the effluent velocity times the area. (There are fluid dynamics effects around baffles that make this kind of rule of thumb somewhat approximate.)

People have different tolerances for how much odor they want in their houses, how much grease and moisture escape they will tolerate, and how cold they will allow their house to get (or their guests to get). This leads to a wide range of views on how well their venting system works. If limited by aesthetics, architecture, and cost, as most of us are, then one can only do his affordable best and accept less than perfect results.


My Clippings has more on this subject

    Bookmark   January 19, 2013 at 8:53AM
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Thanks for the detailed response. Your last sentence said it all as far as where we are coming from in regards to this. "If limited by aesthetics, architecture, and cost, as most of us are, then one can only do his affordable best and accept less than perfect results." We just need acceptable, not optimal.

    Bookmark   January 19, 2013 at 9:57AM
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needinfo1 - you need to check your local codes - Minnesota may require MUA above a certain CFM level

    Bookmark   January 19, 2013 at 10:09AM
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Grilling, especially protein, on a high powered range produces a LOT OF SMOKE!!! That is why the range makers recommend at least 1200 CFM. I have a 6 burner 36" DCS with 600 cfm vent, plus heated MUA. It is adequate for the burners, but I would NOT expect it to work well at all for a grill. The code guys in my jurisdiction look at what the manufacturer recommends for venting before approving the kitchen design. Heated MUA is required for 600+ cfm. My venting system cost about 50% more than did the range.

Sometimes, in some places, you just have to accept that grilling is an outdoor, summer thing. Winter is a good time to make soup, stews, and slow braises.

    Bookmark   January 19, 2013 at 4:23PM
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So, to just throw an easy to calculate figure out, if your range cost $5,000. Are you saying it cost you $7,500 for ventilation?

This is not a complete kitchen remodel or new construction. This is replacing a range and counters and adding a hood in 100 year old house.

I have to say though, looking at what we've been cooking recently, it has ben all about soups and stews here in the dead of winter.

    Bookmark   January 19, 2013 at 5:32PM
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My range was over $6K and the vent system, including hood, ducting (there was none in the old kitchen), MUA, and installation was north of $9K. And the ducting was rather simple, straight up through an attic and out the roof.

I always just shake my head when some recommend oversizing their vent system so they never need to run it at max. We obviously don't live on the same planet....

    Bookmark   January 19, 2013 at 5:55PM
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Yikes! This does all add up! Was it the MUA that made the venting such a pricey proposition?

    Bookmark   January 19, 2013 at 6:55PM
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I grill on my range in winter in Canada. Not sure if it's just the types of meat we usually do, but I almost always only have to run our fan on the lowest setting and it does a fine job clearing the smoke. Sometimes if it's a particularly fatty steak like a rib-eye then I'll need to put the fan on second speed.

When I do need the full power of our 1200cfm fan is after the meal. I don't pull apart the grill and clean it in the sink (too much work, I only did that the first time I used it and that was enough to convince me never to do that again, lol) ... rather I turn the grill to high and use a wire bbq brush on it. If the grill is particularly gunked-up then I'll hit it with a wet wire brush and THAT'S when the crazy smoke happens and I am totally grateful for the 1200 cfms then. But that's pretty much the only time I ever use the full power of the hood. (The fact that at 1200cfm it sounds like a jet engine taking off might also have something to do with it too, if I'm honest).

We live near Toronto and we just open a window at the front of our home even in the middle of winter. Not a big deal to me, so I guess it depends on your tolerance. In our previous home we grilled outdoors in winter and this is definitely better than that!

    Bookmark   January 19, 2013 at 6:59PM
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