This is what makes MUA such "fun." If the air is conditioned, it can be introduced distant from the kitchen or at least distant from the hood and have the best chance of not disrupting the rising effluent plume. If the air is unconditioned and cold, then close proximity is called for (although it is unlikely to be so close as to not chill-out the cook. This could have long-term ramifications. :) Insertion under the range is a good approximation of proximate, but might have these deficiencies: o Some ranges may not like this. Someone on this forum in the last year, I think, pointed out that high-end Brand X gas range instructions prohibited it. I don't recall who X was. I do not know what the basis of the manufacturer's objection was. o For cooktops, cabinets will be in the way. A grill at the feet may be used instead of a cabinet base, and for peninsulas and islands, another on the other side is plausible. Keep in mind that the grill will have to have a rather strong air velocity unless the grill is as large as the hood. Alternatively from floor insertion, a slotted counter top design around the cooktop would provide an ideal air feed location, but inadequate area for the flow rate. Also, it could be an opportunity for difficult cleaning. Pop-up vent systems run backwards come to mind. The air flow onto the cooktop could be disruptive to the flame pattern, so probably should be aimed outward. Flow would likely be too low without a very large pop-up. kas

Hoods that try to mimic actual commercial hoods while retaining a more modest size, practical aspect, and decent aesthetics are widely available from many sources that can be found on the Internet. For example, you can download the Wolf Design Guide and look at the pro island hoods to get an idea. There are others fabricating similar designs. While this is a necessary exercise, the first step is characterizing the parameters of the hood, blower, and make-up air system. To do this, it is necessary to start with the size of the cooktop. If you have already done all the math and know your necessary hood size, then a tour of hood makers' wares is next. Please keep in mind that of performance, aesthetics, and affordability, generally only two out of three can be maximized. Most hoods are compromises within these factors.

All of the above may be true, but are not in themselves totally limiting. In general, there is always a blower that will move a desired air flow volumetric rate through a given duct, but one might not want to operate it, listen to it, or pay for it. But in this case we are on the margin, and feasibility is not prohibited using conventional devices. For example, I have a Wolf/Broan 1500 CFM rated roof-mounted blower operating with a 10-inch duct, and given various estimated pressure losses, expect that it moves 900 - 1000 CFM. A 1000 CFM rated typical hood blower, no matter how large the duct, at a minimum will be significantly restricted by the hood baffles, and at a maximum by any added MUA pressure losses, and would be unlikely to move more than 700 CFM in use with a hood. An 8-inch duct has a sectional area of 64% of that of a 10-inch duct, so the pressure losses operating at 67% through an 8-inch duct of the air flow rate through a 10-inch duct will be similar. In general, one wants to select a blower having a fan curve that supports the desired flow rate at the pressure loss that one estimates is present. Without my looking up the specified hood, let us assume that its entrance aperture is 42 x 27 inches or just under 8 sq. ft. This calls for 8 x 90 CFM/sq. ft. or 720 actual CFM. A typical 1000 CFM blower may achieve this with a 8-inch duct, and one certainly can check the assumptions against blower fan curves (where available) to either ensure adequacy, or at least force the MUA system to be active and not cause significant pressure loss. Note that this doesn't violate your appliance guy's opinion about duct flow rates, although I am sure that his view is based on typical in-hood blowers. If you have the room in some part of the duct path, then including a silencer will help reduce noise back at the hood for only a small added pressure loss. In any case, numerous commercial kitchen ventilation blowers can be found that will pull 720 CFM against any pressure loss likely from a well designed hood/MUA setup. It is quieter to move a given flow rate when the fan blades are large and moving slowly than small and moving quickly, as the latter generates more high frequency noise from turbulence. Induction motors can be controlled by rheostat adjusted phase circuits, and these can be put into hoods. My Wolf hood has such a control, and now the technology allows for it to be performed with better techniques at low cost. These comments are meant to touch on most of your questions, but feel free to delve deeper as needed. kas

Not sure if you’ve already selected your range hood. I do a lot of Asian wok cooking too, and that’s one of the main reasons we bought BlueStar 36” RNB (just stainless steel) last month. With the appliance store salesperson’s recommendations, we paired it with Best by Broan PK22 insert pro-range hood - 1200cfm on internal blower. It worked fantastic and low noise on low and medium settings, the highest setting is kinda loud but i can live with it as i can still keep the same tv volume in another room. We had our hvac contractor to put in the new 10” duct to the exterior of the house and a makeup air component as part of our county requirement. We did consider Bluestar range hoods to pair with but we didnt see the need to spend that extra $ since we can still achieve great results with this particular Broan hood which is less than half the price of a BS one. For us, the installation costs adds up too, especially we‘ve never had an external duct in the kitchen as we use to have a microwave hood.