Am I reading this right...? Your rangetop is 36”, but your vent hood will only be 34 1/2“ wide? Whose great planning was that? Did anybody think to do ventilation research, before designing this kitchen?

The appearance and illumination abilities of any hood are the least of your problems. What you’ve designed is dangerous to to the health of anyone who’ll be in your home, while cooking is going on.

Kaseki and opoane know what they’re talking about. They are the go-to people on this site for all things ventilation. If anyone could suggest an insert for your hood, it would be them. But, I doubt they’d put themselves on the line for something they know would be detrimental to someone’s health.

Front to back depth may be the biggest issue and complete lack of containment volume is also an issue so yeah a fail on at least three points.

Either way this is a good lesson in what not to do and I would place a lot of the irresponsibility blame on Fabuwood - they should know better. Doing this w/ induction would be bad but with gas is amazingly ignorant.

OK people - calm down. I have reached out to my kitchen designer and requested a stop on the Fabuwood Hood Vent. Will be changing to a Chimney style to fit the range. I sincerely appreciate the information - that is why I reached out. It is not necessary to embarass or pile on.

Note - I reached out to Main Line Kitchen first to ask about a job with a picture showing my similar situation. They, I thought were regarded as very good. Again, I only reached out because I was uncomfortable with that arrangement. As my grandmother always told me, you can catch more flies with honey instead of vinegar.

I only have room for a 36" wide hood to go over by gas range. Any suggestion for a stainless chimney style hood vent is appreciated.

I'm heading in to a meeting but I would still do a hood liner with a wood cabinet around it but one more appropriate for your cooktop. At least 22" depth but ideally 27", some containment volume - the more the better, baffle filters (not mesh).

More: https://www.gardenweb.com/discussions/5161173/hood-faq

Glad to hear you’ve reconsidered. 36” is not optimal, but is much, much better. To make up for the missing 4 extra inches, you’ll probably have to increase the BTUs. I’m not the expert on these matters. I’ll leave that for @opaone and @kaseki, should they return.

I do know enough to say this, avoid those flat bottomed chimney hoods that are often posted. Their ability to capture effluents is minimal. Oh, and it’s not just about the width of the hood, but also the depth.

Thoughts on the Zephyr Titan? I appreciate the feedback - so much to take in and with COVID, hard to see anything in person.

Whenever I start grumbling to myself about having to write the same thing several times per week I remember that the reason I started commenting was the terrible advice being fomented by appliance distributors, some of which I suspected at the time of coming from hood manufacturers or range manufacturers not wanting their potential customers put off by the necessary added expense of dealing with kitchen ventilation.

I sometimes forget that some who come here for advice are not even aware that ventilation is a big issue and that someone has to research the particulars of his or her situation to find a solution.

In this forum I deal with the issues of odor and grease removal; @opaone has special interest in respiratory health. I do not recommend hoods I haven't owned, but I will criticize those that deviate so far from functionality that they should only decorate poser kitchens.

What a hood is supposed to accomplish, besides being a fire stop, is capture and containment of cooking plumes. Capture is getting the plume effluent into the hood (below the baffles) without spillage into the room; containment is getting the effluent through the baffles and thence to the outside (or less desirably, through aggressive grease and odor filtering back into the house).

No hood one could stand can suck up cooking effluent from the pans underneath. Instead, the plumes rise and expand, and the hood overlaps them and entrains the effluent into the hood air flow. To deal with expansion, the hood needs to be larger than the boundary of all the pans that might be used. While there is some capture possible at the edges of a hood, this zone is rather small, so if one is limited in hood size, hot cooking (vaporizing cooking oil and grease) should be done on inner burners. Typically, a horizontal extent achieving 3 inches beyond the appliance is deemed adequate for hood heights up to 36 inches above the cooking surface. Front to back distance (for wall hoods) should also extend three inches past the cook's side of the cooking appliance, although if the air is somewhat channeled by side skirts or cabinets, this might be relaxed to 3 inches past the burner.

Once the hood dimensions are known, the entry area can be computed. You should strive to achieve 90 ft/min through this area for residential cooking with residential hoods. Hence, the volumetric flow rate (CFM) should be 90 ft/min times the area (square feet).

As it happen (with quite a few devices dealing with losses, actually) the rated blower CFM of a hood or hood system is not the CFM one will get with the various pressure losses (air friction) present in a hood system and the counterpart make-up air system or path. The actual blower flow rate as a function of pressure loss is given by the "fan curve" available from responsible manufacturers. Without calculating all the pressure losses, one might just conservatively assume that the actual flow rate with be only 2/3 of the blower's rated (at zero static pressure difference) flow rate. So the hood system blower should be selected to be rated at 1.5 times the CFM determined by the hood area times 90 ft/min calculation.

The duct should be sized so that the actual expected flow rate (not the blower-rated flow rate) causes a velocity in the duct between 1000 and 2000 ft/min.

If room allows and the blower is not in the hood, a silencer can be inserted in the duct path for improved noise isolation.

If the actual flow rate is higher than 400 CFM (and one should consider lower thresholds for good efficiency and health), many building codes adopt the requirement that deliberate make-up air (MUA) be provided. This can be done passively (big duct) or actively (with a duct blower). It may be necessary to heat the MUA. In general one would also want to filter it against dust.

Note that whatever flow rate is achieved through the hood is exactly the flow rate that deliberate (or accidental through wall, window, and door leaks) MUA is achieving in replacing the house air.

Rather than further beat these topics to death, I suggest the OP read the first dozen of so pages of the Greenheck Guide, available here: https://www.tagengineering.ca/wp-content/uploads/2015/02/KVSApplDesign_catalog.pdf

Commercial kitchen ventilation is the standard for performance and efficiency that residential systems should strive to approach, given that doing so will be limited by ceiling height and space of a residential kitchen, along with greater demands for low noise.

There is a wealth of commentary here in many many hood threads that have been spawned over the 13 years I have been present on the forum. Some of it may be helpful with the big issues related to integrating MUA into an existing residence; others may provide insights into hood inserts and other variants.

I recommend (because I have one and the guide is useful) perusal of the wolfdesignguide.pdf, available somewhere on SubZero/Wolf's web site. Example of hoods and hood inserts may be found there. If the only solution to a problem is made to order, then companies such as ModernAire may be consulted.

Last for this message, I repeat that at best, only two of performance, aesthetics, and affordability can be achieved. Usually, one has to trade among these for the best perceived fit to all requirements.

Ugh, I think I’ll just eat cold sandwiches

Nancy, I don't have the Titan, but I have a 48" Siena Pro 1200 cfm Zephyr chimney hood and I love it :)

Thank you!

"some of which I suspected at the time of coming from hood manufacturers or range manufacturers not wanting their potential customers put off by the necessary added expense of dealing with kitchen ventilation."

Excellent point on their irresponsibility - profits before people (and I'm a rather ardent capitalist but capitalism can and should also be considerate of humans).

And combined w/ the U.S. HVAC and Energy industries being so far behind more advanced countries on ventilation and other things along with our seeming aversion to opening windows or being out of doors unless temps are between 74.3° and 76.2°, winds between 1.3 and 2.1 MPH and cloud cover no more than 14% it's no wonder we have such poor health, highest in the world healthcare costs, highest rates of chronic disease and lowest life expectancy of all developed nations (there are also issues of our sedentariness and poor eating but I digress...).

--

"containment is getting the effluent through the baffles and thence to the outside"

Yes. Or more specifically to contain the effluent until it can be exhausted. Without proper containment volume (basically empty space) the bursts of effluent will be captured - will be in the proper place to be exhausted, but the amount of effluent rising up in each burst is much greater than the amount of exhaust (by a factor of 7x or more so higher CFM's can't really help) so without proper containment volume the effluent dissipates in to the surrounding kitchen. This is why commercial hoods are all big empty boxes - a place to contain the effluent until it can be exhausted.

The Zephyr Titan at least has very minimal containment volume compared to the earlier hood that had zero containment volume. It's also 24" deep vs 13". So on these two scores is a good improvement.

Hi I'm in the same boat here. Ordered fabuwood 36 inch hood that only takes insert up to 34.5 inch w X 13.75 in depth. Width is not an issue but very hard to find only 13.75 inches depth with a decent power. Any suggestion is greatly appreciated

Un order it. It doesn’t work with the real world needs of ventilation. Its irresponsible of them to even sell it. Fabuwood is a terrible company.

This was such a hard decision but after weeks of talking with our kitchen designer and appliance dealer, we finally decided on best PK2230. We are having it custom cut to take the deeper size. I’m happy with the 1100 cfm and hybrid baffle filters options. Tear out scheduled for late June and so excited to get this underway.

@stdhkim Kim, 13" is much too shallow for a range hood. It will perform poorly and increase health risks for you and your family.

More: https://bamasotan.us/range-exhaust-hood-faq/

Nancy, I seem to be in the same dilemna as you were. Ordering a cabinet hood that is 36 wide over our 30 in range. The insert apparently needs to be 32 1/2 x 18 or less. ABT appliance is saying their inserts are 34 inches. Suggestions?

Because hood liners are undersized relative to standard cabinet widths (so that they fit into standard cabinet dimensions), one must choose an insert size for a hood that is larger than the nominal "six inches wider" standard for good cooking plume overlap. For example, Wolf has these widths for liners: 34 3/8" (873) , 40 3/8" (1026) , 46 3/8" (1178), 52 3/8" (1330) , 58 3/8" (1483). It may be deduced that each of these fits within cabinet sizes that are multiples of feet or multiples of feet plus a half foot. So, for good capture of a 36-inch cooktop/range one should choose the 46-3/8 size for a 48-inch cabinet. This will support a 36-inch gap from cooktop to hood, perhaps a bit more. The 40-3/8 in a 42-inch cabinet will be marginal for some plumes and hood heights (sear steaks on center burners), and the 34-3/8 unacceptably narrow, in my view. The front-to-back dimension should be the largest available within the limits of whatever other trades factor into the design.

@Sheila, Rangecraft has a Fabuwood insert on their Clearance page. Don't know if it is the size that you need but might be worth contacting them.

@Nancy Carey how did your hood/insert turn out? We're in the same boat with the Fabuwood range hood - I'd love to learn about your experience and what you ended up doing. Feel free to private message me! Thank you

Hello Nancy Carey, I’m in the same situation, I have the Fabuwood hood and cannot find any decent insert. Could you please let me know if you kept the Fabuwood hood or you found an insert to fit in? Please let me know, thank you!

I did! Had it customized to fit a Best Hood. Very happy and works perfectly

PM me and I can send a pic and model

Hi Nancy.

I can’t figure out how to PM. Can you share the make and model with me as well?

Hi Nancy, I'm just about to order a 36 inch range hood from Fabuwood and would also love to know the model you ended up using but not sure how to private message you either

Nancy, same problem here. Cannot find the PM feature anywhere.

"Hi Nancy, I'm just about to order a 36 inch range hood from Fabuwood"

I would not do that. From what we've seen on here these are made much too small for any kind of appropriate exhaust hood. If all you ever do is boil water on an induction then you'll be OK but otherwise you need to get a proper hood for your and your families health and Fabuwood appears to prevent this.

More: https://bamasotan.us/range-exhaust-hood-faq/

opaone

I'm still trying to learn why the fabuwood range hoods would not be sufficient enough? If a range insert of at least 34 inches with no less than 600 CFMs is installed in the 36" hood how would that still be harmful? I started going down the rabbit hole last night after reading this thread and, while reputable sites recommend a fan hood 6 inches bigger than your range, it appears that - according to the same reputable sites, at a bare minimum, the hood should be "at least" the same size as your range. I know from the burner output of the range I'm currently considering that I should have at least 600 CFMs so if I can accomplish that with an insert that fits properly in the hood, how can I go wrong? i'm trying to educate myself - we are doing a remodel - going from a 30" cooktop with nothing more than a crappy 30" over the range microwave that we believe is approx. 300 or so CFM as my existing exhaust fan that has served us well over the last 20 years - a bit loud but was always sufficient enough in moving things along as we cooked. Looking to go to a 36" range with a 36" hood and insert. Your thoughts?

teresa cai,

i've never commented on this site before, but after doing some digging last night, i think we would need to follow nancy and she follow us in order to private message her... i could be wrong but i searched everywhere on how to do that

I think the primary problem with Fabuwood is depth. You need at least 24" depth and ideally 27-30".

For a 36" range, induction or gas, you should have a 42" wide x 24-30" deep hood. If you don't capture it and contain it then you'll not exahust it no matter how many CFM's. A consumer hood that is the same width as a range can capture as much as 40% less than one that is 6" wider.

And as I've noted many times before - CFM's are a marketing thing. DO NOT rely on CFM's. CFM's are nearly meaningless if the hood does not have appropriate capture and containment.

Hood Vent - Best PK22

Opaone,

Thank you. I appreciate you making things a bit more clear to me. I'll do my due diligence and this thread will either have been a blessing or a curse lol

I basically went with Fabuwood for this hood and my kitchen design is complete. I'd have to take many steps back in time at this point and it is something I'm hoping not to have to do

Hoping Nancy Carey will jump in at some point again and tell us what she ended up doing

Nancy,

Thank you. How did you customize this insert - was that through Fabuwood? I see the depth is approx. 15inches. Also, is 1100 CFMs what you have?

I had my kitchen contractor handle but yes, Fabuwood did the modification- they charged $700 for that 😖 - but I wanted that larger unit and I had a wood veneer along the front to match my white oak floors. Beautiful result so, not going to complain about the cost. Yes, 1100 CFMs.

Many threads here address this in deeper detail, but as a reminder: Hood blower flow rate (CFM) assertions are for the blower hanging in free air with no difference in the static pressure between input and output. The ratings are not the flow rates when mounted within the hood system, in-hood, in-line, or external. The ratings do not address baffle/mesh filter pressure loss, duct pressure loss, insufficient make-up air pressure loss, etc.

Required CFM first depends on hood construction, but for typical residential hoods the requirement is to immediately capture and ultimately expel to the outdoors the cooking plumes without any hood spillage. This depends on the cooking being done, hood overlap of the plumes, and velocity of air through the baffles and by extension into the overall hood aperture (capture area). Please review a number of hood threads on this forum to gain perspective on how the requirements are established.

Cost and aesthetics are also in the trade space. It is best if the performance relinquished as a result of cost and aesthetics considerations is understood when effluent removal, deemed inadequate by those of us who value performance above all else, reveals itself in actual operation.

☺️

Nancy, sounds like I am going to have to go this route as well and searching for appropriate inserts now and will get back with our cabinet company to have this increase in depth done as well.

Kaseki, I'm learning more about this and who knew this was such an in-depth topic! Your input here is appreciated and I will use it to gain more perspective in my continued research.

Overall, I'm feeling much better today than I was last night when first reading this thread

Thank you

@Sherri Costello-Clarke Sherri, when will your cabinets arrive? My Fabuwood cabinets are coming next week, I already ordered the Best PK2239 with 1300CFM internal blower. It’s a special order, cannot be returned, hope it will fit property.

Nancy Carey Is your hood reasonably quiet? Any complaints? How long have you had it? My hood is intolerably loud, on anything above low speed. I have an internal blower (actually 2 blowers which amount to 1200 cfm). I'm trying to decide whether conversion to a remote blower would help. I'm starting to wonder if it would be cheaper and better to just buy a different hood, unfortunately.

We've had it since Sept 2021 - It's reasonable quiet on the first 2 settings - OK for 3rd and it sounds as if the roof is lifting on the 4th. Honestly, I don't fry or stir fry so low simmering and boiling water are about it. We use our outdoor grill mostly. We're very happy with our choice - but certainly can understand that not all people cook the same. Being empty nesters that go out a lot, when we do stay home, we want simple and quick.

There are two ways to get quiet that I can think of, given residential hoods and blowers.

(a) Use a duct path long enough to fit a silencer and put the blower on the roof

(b) If a silencer can't be fitted, use a remote blower that is oversized for the job and run it at partial power

No powerful hood with internal blower is going to be quiet with the blower two feet from the cook's ears.

Nancy, Thank you!!! You have a Fabuwood hood with a Best PK22 blower, right?

kaseki Thank you!!! Four questions (which is too many). First. Have you heard of mounting the blower & silencer to the side of the house? Build a box around it and a door to service it. Would be expensive because it requires siding, waterproofing, and shingles. But to get it on the roof, we'd have to have at least 3 turns. I know you can't go over 3 turns. Whoever installs it will probably want to do 90 degree turns, because it's tight. I know you're supposed to stick with 45 degree turns. Getting to the roof will also be a fairly long run. Second. One problem, I think, is that the duct exits the hood from the top, and does an immediate 90-degree turn. This probably causes turbulence and fan tip noise. It should have been a rear duct, which is an option with our hood. Third. I spoke with a Vent-A-Hood sales rep. He said Vent-A-Hood is quieter than my Bluestar hood because Vent-A-Hood uses 4 internal blowers to reach 1200 CFM. My hood has 2 internal blowers (600 cfm each). He said a remote blower would be even louder, because pulling air is harder than pushing air, so the rpm's would have to be higher. Do you know much about Vent-A-Hood? Last, I read that you shouldn't run hood ducts downward, because hot air rises. Have you heard anything about this? I'm trying to figure out our options.

Well, let's see if I'm up to four questions all at once.

Rule no. 1, do not believe VaH sales persons trying to explain blower operation unless you have some other means of determining their veracity, and most importantly, their understanding of the fluid dynamics of air.

Rule no. 2. Blowers that suck air also blow air and cannot know what is the cause of the pressure differential across the blades, at least at the tiny pressure differences that apply to hood blowers. Pulling air could be a problem when the intake is at feet of water column reduced pressure, not inches. This does not mean that the blowers will be unaffected by operating into a duct bend, or from a hood transition, etc., but in general, even a VaH blower is pulling air from one side and pushing with the other side, and its blower, like all others, is constructed for one direction of air flow and to achieve a particular flow rate performance at a tolerable sound pressure level.

I don't keep up with VaH, but I thought that their 1200 CFM (claimed) hood had two 600 CFM blowers, not four 300 CFM blowers. Perhaps they are using two motors, each with two cages.

Fan blade tip noise is caused by the turbulence of the air spilling from the blade tip. It results from operating at a high speed exacerbated by spilling from a crude airfoil shape. Casablanca ceiling fans move a lot of air but the turbulence is at most modest due to the low speed of each blade tip.

Duct noise is from irregular air flow in ducts. It generally won't be laminar at the flow rates of interest (1000 - 2000 ft/min). Pressure loss of bends is the result of degrading the flow due to increased side wall interaction as the moving air tries to pile into the blockage ahead before turning. Smoother longer turns reduce the effect.

VaH Magic Lung blowers use squirrel cage designs that are good, I guess, for throwing grease at the hood walls, but have a weakness -- they don't like added pressure loss relative to some other popular fan configurations, such as axial in-line blowers or centrifugal carousel types such as Wolf/Broan/Abbaka roof blowers, so actual flow due to inadequate MUA or constrictive ducting will have a greater effect on actual flow rate than these other designs.

It is certainly possible to build an external chase for ducting and even for the silencer (about 4 inches larger in diameter). Number of bends is worth minimizing, but it is always possible to specify a blower to provide the needed flow rate at a given pressure loss if the bend number cannot be minimized.

Roof blowers usually also work mounted on walls. One secondary effect is that on roofs, sunlight UV generally degrades and eliminates any grease that condenses on the blades and is expelled onto the shingles, whereas on siding that is in shade the grease may become noticeable. Commercial blowers operated in up-blast or side-blast configurations likely will not blow grease onto house surfaces, but condensation within the unit may lead to some release around the unit.

Downward ducting has a couple of deficiencies. The process of turning a rising plume to a downward direction requires additional energy (equivalent to pressure loss) and likely causes the grease particulates that escape the baffles to condense by impingement early rather than being expelled. To keep the typically long horizontal underfloor duct path from dripping, a continuous down tilt will be desirable, and in a typical basement this may lead to requiring a hole in concrete rather than in a wood wall. Some municipalities may not approve such paths.

The "heat rising" view is probably less relevant because the duct velocity will be at least 10X the velocity of the intake to the hood.

Last, an observation. My hood blower is rated for 1500 CFM and is roof mounted. Actual flow into my hood is about 1000 CFM with presently passive MUA. This is 100 ft/min air flow across the hood entry aperture. I have a 10-inch duct with LD-10 silencer. Flow is 1800 ft/min in the duct. There are three bends, all less than 90 degrees to get the vertical hood direction to a shallower direction in my attic that encompasses the silencer, then two more partial turns to match the roof blower's intake angle. Note that configurations of this type not only allow room for the silencer, but also allow the hood exhaust to be placed more optimally on the roof, if needed, than exactly above the hood.

I hear mainly baffle hiss at the cooktop, with a slight underlying rumble, likely due to imperfect fan carousel balance interacting with imperfectly stiff roof planking.

Edit: I feel comfortable asserting the baffle pressure loss, and MUA pressure loss, dominates all the pressure losses in my duct path.

tl;dr: An external blower downstream from a silencer will always be quieter than a blower in the hood for a given flow rate so long as the external blower is not constrained to being significantly smaller than the in-hood blower. Other noise will depend on whether the baffle size and shape is reasonable for the air flow rate and the duct size is such that the air flow in the duct is in the range of 1000 to 2000 ft/min.

Let me know what I forgot to answer.

kaseki Thank you! I appreciate the help! I need to read it again, probably a few times. It's complicated, but getting clearer. Gonna sleep on it. Approach the subject again tomorrow.

Im in the same boat , just instinstalled the allure galaxy 36 inch hood, . It has an arched front and metal liner with a rough opening of 19x9 and 7 inches high?? help

Any fans that will fit those measurements? Or Do we have do modify it?

Zero inserts fit that. Or would provide adequate ventilation, if they did fit. The solution is to customize the cabinet hood for extra depth, or ditch it entirely.

These hood apertures that do not extend very far from the back wall provide cooking plume capture and containment for only the back burners, at best. Some will find that limitation acceptable with appropriate cooking techniques. Here we generally tout ventilation system requirements that allow hot oil cooking on any burner or hob.

If the hood and liner do not fit a blower, then an external blower can be used, but the control has to be appropriate and mounted somewhere. Rummaging around the Broan/Best/NuTone site should reveal various types and sizes of blowers and controls.

I won't get into the debate of what is right and what can work and what is done. For many years, it has been acceptable to have a microwave over the range and that will pass a building inspection. If you are purchasing a gas range with an indoor grill - that would not be acceptable and I would never design that way.

The reality is these hoods are sold 36 over a 36 range. I make my customer do 6" bigger. That is the hood and liner. The blower is what need to go into the opening you are talking about and you can find ones to fit from ZLine. Fabuwood hood liners have and opening 1 1/2" narrower than the width of the hood and 13 3/4" deep.

Care should be taken based on what you are purchasing. Get the best you can - it will be better than a microwave or no hood at all ( in many areas there is no requirement ).

Best of luck to everyone - stay safe