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Reply to: An inline blower will not short out - and they are much quieter than in the hood motors. Use a silencer between the hood and motor and you will hear nothing but the air. This makes it more likely that the vent will be used - keeping grease and other pollutants out of the home. Condensation happens when warm - moist air hits cold air. Insulating the duct work in an attic will prevent the majority of this - along with placing a backdraft damper right before the wall/ceiling. Finally - if the duct work is running horizontal (as opposed to straight up to the roof), and they are worried about condensation, slope the duct work toward the outside wall so any water that does develop will flow out the vent. Both options you mention make good hoods. Fantech is another good company. I prefer a variable fan speed over fixed setting speeds. Best of luck.

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Reply to: Attempting to move significant air (as required for hot oil/grease cooking) will always be noisy unless a very large diameter blower is used at low blade speed. For quiet operation, standard blowers should be in-line or external, and a silencer used between blower and hood. I agree something is wrong with the design or fabrication. However my Wolf is a Pro Island hood, so its configuration may be different from yours. See image.

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Reply to: Strongly suggest you look at a Modernaire custom hood liner, coupled with a remote blower mounted in the attic or on the roof. Equipped with an inline silencer, it results in high cfm ventilation with an extremely low noise level. No in-hood blower can come close. And Modernaire will build your custom liner to the exact specifications you want in all dimensions. Extremely high quality construction with the LED downlights you requested. Speaking from experience--we've had one for 15 years, and have a second one for the lake house on order as we speak. Can't recommend highly enough vs what you're listed. Oh, and cost is much less than you'd think for a custom piced--quite competitive with off the shelf options.

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Reply to: As usual, kas has the physics of airflow down pat--listen to him, there's real wisdom there (though an engineering degree helps :-) ) The Modernaire I'm suggesting is a hood LINER, not a hood. It goes inside your custom hood surround. It's very affordable, and gives you unlimited ability to customize size and configuration. As kas notes, you can mount a remote blower in a wall just as easily as on a roof and it's far superior to any -hood blower system. If you're serious about looking at best options, I'd strongly advise a conversation with Modernaire. They're great folks too, and super helpful. We're using a Fantech MUAS 1200 for MUA on the current kitchen reno.

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Reply to: Broan/NuTone/Best make a large range of ventilation equipments and generally you get what you pay for as far as I can tell. However, why a "high end" appliance dealer wouldn't include some other brands is unclear. At a minimum, I would expect a Wolf dealer to have examples of Wolf hoods. (My hood is a Wolf, made by Independent before Wolf moved production in-house.) Decide how high you want the hood for good site lines and reaching to the back burners, and missing one's head, while keeping in mind that the front burners will be emitting plumes that expand as they rise, so height corresponds to increases in needed overlap -- side to side and front to back. 10 degrees from vertical measured from the flame diameters when pans are on the burners can be used for plume expansion estimation. Sketch it out. Given a height and hence width and depth, calculate the square footage of the entry aperture of the hood. For wall hoods the light bar in the front may qualify as partial or whole entry aperture area. Multiply area by 90 CFM/sq. ft. Multiply by 1.5 if you don't know all the pressure losses. Find a blower that has that result as a rated value. Decide on in-hood, in attic (in line), or on roof. Farther away is generally quieter. If there is room for a silencer (Fantech) between blower and hood then the result will be quieter still. There is a lot of dissension about ease of hood cleaning by type. I can say that my Wolf hood baffle assemblies easily remove and can be cleaned in a dishwasher. (I have ten of these, so it takes two loads.) One still wants to reach up inside and wipe the surfaces. I use Simple Green, but likely there are myriad possible choices. I have never owned a VaH, and was initially repulsed (2007) by the Magic Lung® claims. Others like them. If you have guests sitting where they can see into the hood, a baffle system may be aesthetically superior. Duct should be sized so that full power actual flow rate achieves a velocity in the duct between 1000 and 2000 ft/min for best balance between grease condensation and grease impingement. You can go lower (larger duct) if you pre-heat the duct in cold weather. On CFM focus. Standard (if that actually ever applies) residential hoods are designed to fit into residential kitchens. Commercial hoods are designed to fit into commercial kitchens. At a minimum, the typical difference is two feet of ceiling height. When the commercial hood can be built so that there is tremendous volume below its baffles, there are conditions where the specific flow rate (CFM/sq. ft.) can be reduced below the value I suggested above. This is due to "baffle averaging" resulting from the reservoir volume vs. plume steady state and transient volumetric rates. At the other extreme, residential hoods with little volume below the baffles will allow plume escape (capture failure) if the plumes are not immediately entrained into the baffle flow. And, of course, plumes not initially captured are not contained and removed except as a matter of long term kitchen (and whole house) air replacement. So CFM focus varies. Another difference is that commercial hoods are typically operated at a fixed CFM and the MUA is balanced for this case, whereas residential hoods, along with bathroom fans, etc., operate at variable CFM, and this makes the MUA control more complex.

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Reply to: Been a long time since I participated in ventilation discussions, but felt moved today. And this may sound a bit catty, but...IMHO if you are seriously considering a Vent a Hood, you have not done enough research. Find a comfortable chair, a a glass of scotch, and then start digging into threads like these: Please help with ventilation Nice discussion spanning years. Watch particularly (in this and all the other threads) for posts from kaseki, the resident ventilation guru Exhaust Hood FAQ II From another resident guru, opaone. And it links to a website he's (or she's--sorry!) created: Range Exhaust Hoods are Critical Which will get you well into the weeds. Hugely helpful (though I think it's a bit overly dogmatic in the rejection of "consumer grade" hoods--much of his concern can easily be addressed when choosing a consumer grade hood by simply sizing the hood to get adequate capture area). As you gain insight, I think it will become clear why Vent a Hood falls far short. Noisy, overpriced, a huge PITA to clean, and an underperformer (don't buy the "CFM multiplier" nonsense). You'll see as you research that most people who tout VAH either own just one hood and have never had another to compare to, or they sell or market them. I've owned two VAH, but have a custom ModernAire hood liner with a Fantech remote blower and silencer in the attic in the main house. It's like comparing a 2014 Chevy Impala to a 2021 Porsche Panamera. So, focus on adequate capture area, appropriate CFM based on your range, adequate ducting (10" highly preferred). Choose baffles over mesh or "squirrel cage." Consider remote blower with silencer if it works with your installation. And install adequate MUA! Spend a bit more now and you'll appreciate it for many years to come.

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Reply to: Thanks @clinresga! I'll definitely look into those threads (and the scotch) :) A Modern Aire hood liner with a remote Fantech blower sounds like the perfect setup, but I don't think I'm going quite that fancy. Instead, I'm leaning towards Victory Range Hoods Twister Max (1150 CFM with 10" ducting, baffles). It's a good value and appears to be built well enough. Also, they have pretty solid reviews on Google! My wife and I also have decided to go with an induction stove, which should cut down on some of the combustion pollutants that come with gas ranges.

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Reply to: Regarding MUA, I will be getting a motorized MUA system that turns on/off with the range hood (but does not modulate, so it won't exactly match the fan speed). I'm okay with the inexpensive compromise. My HVAC person also is running the ventilation for the gas dryer and gas furnace to the roof (instead of the back patio area) at no charge. The plumber is charging $450 to run the water heater venting to the roof. All in all, not a bad price to improve outdoor air quality and get those fumes away from my windows and patio

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Reply to: "(but does not modulate, so it won't exactly match the fan speed). I'm okay with the inexpensive compromise." This is a little confusing as there is typically little to no cost difference to have the MUA blower CFM match that of the exhaust hood. This is a motorized blower and not just a motorized damper correct? Electro Industries for instance is a simple all-in-one MUA. Put a sensor coil on the hot lead for the range hood, commission it (e.g., measure CFM of range hood on Hi-Med-Lo settings and then set MUA to those same CFM's, and it's done). I believe all fantech blowers are now variable speed and you just use an outboard controller with them. Depending on your hood, the CFM's and how properly sealed your house is you want the MUA to match the range hood. "How much CFM loss am I looking at?" Depends on the fan curve of your blower. With some it would be minimal with some it'd be very substantial. "My concern is air quality." Again, this depends on a number of factors. If you're a typical American and keep windows closed and ignorantly think that your inadequate HVAC ventilation is keeping the air in your house healthy then it's likely not much of a problem. :-) Otherwise I'd find some place to exhaust to that will not keep you from opening a window. No matter how good of grease extraction your hood has there will be a lot of gook and odor in what's exhausted. If it's really poor then you could also end up with some grease buildup on the windows.

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Reply to: Roof is generally better, but YMMV. Seriously, while the effluent from a wall cap is typically directed downwards, wind conditions can certainly move odor and grease particulates toward open windows, if present. The best approach is a roof mounted blower, with a silencer in the attic (if present). Of course, this depends on architecture for the duct path, where on the roof it can be mounted, what location the MUA might be taken from, inconvenience of servicing (roof slope, etc.). Whether roof or wall, the blower has to be sized to address the pressure loss of the equivalent feet of duct (varies with air flow and duct diameter), the baffles (varies with airflow) and make-up air system pressure loss (particularly if passive, but perfect balance if active is improbable). By sized I mean that the goal is for the actual flow rate to be the desired flow rate at the pressure loss corresponding to that flow rate. Wolf engineering can provide such curves for their products. Broan provides fan curves for their blowers, but I don't know whether they will supply pressure loss curves for their hoods). I anticipate that except for the quasi-custom makers such as Abbaka and Modernaire, such data would be hard to obtain. Else, based on 90 CFM/sq. ft. of hood entry aperture to find the desired flow rate, multiply the desired flow rate by 1.5 as an estimate of the pressure loss effect and obtain a blower capable of that value in free air (where blower ratings are made).

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Reply to: Go back to my fan curve illustration. If the MUA is constricted, then one moves to the left where the pressure loss line intersects the fan curve line.* This reduces hood blower performance over performance with less pressure loss. Obviously (I hope) one can make up for this by adopting a more powerful hood blower, if feasible. Or one can augment the MUA path with a blower. The issue of negative house pressure, and there will be a little even if all the windows are open when they have screens, is, from the safety point of view that I consider primary, a possible cause of combustion appliance back-drafting. If that is not an issue, then there is the question of what is coming in that is unfiltered and what is being entrained when house leakage is being deliberately or inadvertently utilized. Ignoring code requirements that are based on blower rating and not actual flow, and possible conditions where opening the windows is not going to be tolerated by the occupants, I have no problem with outdoor air (at least where I live -- NH). There are places where outdoor air would advisably be filtered, and in these cases active MUA is needed because the pressure loss of the filtering is significant. The image below is from a message another forum member provided. Some of these pressures are very low and a single screened window might reach them for a hood blower of reasonable size. There is another important factor: Even if one has ducted appliance exhaust and separate ducted appliance MUA, there is a negative pressure that the appliance will backdraft at due to its own lack of perfect sealing. ____ *For our purposes of hood blower performance, the pressure loss is the pressure drop going from the cooktop to the outside and thence back to the cooktop via whatever MUA path is being used. For back-draft issues, the negative pressure is measured from the area near of the appliance to the outside.

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Reply to: I've done some more research as well as reading MUA threads, and also internalizing the advice on this thread. It seems to me I have two 'smart' options: 1) passive make up air system (and opening windows) used with a 500 CFM range hood or lower. Total cost: $800 (hood) + $650 (make up air) + $350 (ducting) = Roughly $2000 2) active make up air system used with a 900-1000 CFM hood Total cost: $1300 (hood) + $2500 (fantech MUA with builder mark up) + $350 (ducting) + $1000 for an ERV or heater = Roughly $5500 Does anyone know if the heater or ERV is effectively required in an area with hot, humid summers and cold winters? My guess is that this is likely. Given I'm going with an induction stove, but will have 45' of ducting through the roof, is this first option basically a waste of time (a poorly functioning range hood that does little to improve indoor air quality while cooking)? One other concern I have is maintenance costs: will the active make up air system last 10 years, 20 years with everyday use? Thanks for all of the great advice--you've helped me tremendously in areas where my builder really should be doing better..

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Reply to: @kaseki thank you! now reading about installing a silencer to help with the noise which is important to me as well as the other more important features!

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Reply to: Those are all interesting solutions. Here are a few other unique hood solutions that might inform your decision.

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Reply to: 1. & 2. Best is overlap, although for many this is not a convenient or aesthetic option. Without overlap, some rising effluent will be missed and either deposit grease and moisture somewhere (as well as spread odor) or will hang in the air until the ventilation slowly removes it. With excess CFM, one may argue that there is an "aura" of air flow around a given aperture that effectively extends its size. This aura will be small, but might reach 3 inches. However, given baffles that had, say, an inch of water column pressure loss at 90 ft/min, and hence a big part of the 1.5X factor (with good MUA) for choosing the blower rated flow rate, if the flow through the baffles were significantly increased the pressure loss would also increase (not necessarily linearly) so the point on the fan curve would change, partly negating the excess flow. In other words, whereas an 1100 CFM blower might yield 700 cfm when used with an 8 sq. ft. baffled aperture, reasonable MUA, ducting, etc., with a 6 sq. ft. baffled aperture it might only move 600 CFM. Still more than the 540 recommended for six square feet, but not overkill. Assuming a continuous blower control (300 - 1100 say), you can just not turn it all the way to full speed. Now, as the real aperture dimensions start getting smaller and smaller due to cabinet factors and dimensions of standardized inserts, turning down the blower may also prove useful just for reduced baffle turbulence noise that the silencer cannot help. Your contractor may be fazed by the MUA when he finds out that it needs to be separate from the furnace system for a variety of reasons that jwvideo spelled out in a recent thread. Sorry I don't recall the thread name. Best is to have the furnace have its own MUA to avoid backdrafting. Ditto hot water heater if separate. Or use a mechanical room to house such stuff with its own MUA and closed path to the kitchen. 3. & 5. The most important reason for an external blower in my view is the ability in some cases to fit a silencer in the duct path. This is the most useful addition to the ventilation if one likes to chat while cooking. Typically, this requires an attic space and a roof blower, but some duct schemes (through garages, for example) may allow room for a silencer in a below kitchen ceiling horizontal path, or potentially one could be used in an external chase rising to a top-mounted blower. Note that a Fantech 10-inch silencer is about 14 inches in diameter. External blowers like the Abbaka and similar shaped Broan and Wolf blowers are typical because they have low profiles and blow down the roof. Commercial up-blast designs can also be used, and may have advantages depending on types and depths of snow. (I have a Wolf/Broan 1500 CFM unit.) If you want to use Abbaka, for example, but buy an ModernAire liner, for example, then ModernAire needs to know that they have to provide a control, or space for a control, compatible with the Abbaka blower. I think Abbaka, Broan (and hence Wolf) blowers are all induction motors, so appropriately sized triac/diac or more sophisticated semiconductor continuous controls should work. I think I could rip of my Wolf (Broan) blower and substitute an Abbaka and use the Wolf hood (actually made by Independent) triac/diac motor control with it. These blowers are not too noisy on the roof relative to nearby areas, but can be heard. For consideration of mounting on the side of a house: one would have to ask, are you in Londonderry, NH where the lots are 2 acres, or in a suburb of San Francisco, CA where 2 meters separates the house from the property line. 4. I have no information or experience about Miele liners. I only have a Miele dishwasher. I don't have a ModernAire ventilation hood either. Their name comes up because they are known to build custom hoods that many are pleased with. They are not the only such source however, so serious trolling of the Internet may be useful. I found in my reno it useful to buy everything early so I could carefully measure details that are hard to otherwise determine that influence the cabinetry and outlet locations. However [prime caveat], your warranty may start when you take delivery (Wolf is rather generous on this point) and in at least one claim raised here, Modernaire would not correct a problem after many months of the liner not being opened and inspected (as I recall). So, try to avoid taking a few years to finish your reno. Also, on that point, you may find it helpful to make lower cabinets deeper than standard to more easily fit plumbing, electrical, refrigerator depths, etc. It just costs a little more to do so. If I forgot to answer something, don't be shy about bringing it to my attention. kas

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