houses14, my Imperial range hood is not an insert, rather an under cabinet ss hood. However, the materials used, and the quality of construction, the fan motors, are the same with minor variances to allow for space restrictions within the smaller size of my hood. Construction wise, it is all that I had hoped for, was easy to install, and has functioned beautifully. Packaging and shipping were excellent. The ss is marine grade. This means that the amount of chromium in the ss will prevent rust from forming in the interior of the hood over time. The electrician informed me that their fan motors and switches appeared to be top quality. The warranty for my hood is 7 years, which is almost unheard of in the industry. Their specifications and installation instructions are right on to allow for optimal operation. For example, my duct is 8" from hood to roof jack and had to have a certain rise in height from the hood before the first angle in the duct work. Baffles remove and reinstall easily for cleaning. It was a joy to call Imperial direct with technical questions at their manufacturing headquarters in California. Someone was always immediately available to answer my questions regarding their vent hoods or recommended installation. My installer was promptly referred to their engineer for technical assistance as I requested that the wiring that would automatically turn on my hood once a certain temperature below the hood was reached be disconnected as I did not want that feature. To me, having that level of service available when answers are needed means a great deal. I found that the folks at headquarters were always honest even if it wasn't the answer I wanted and that they knew their stuff. Their light and fan switches are continuously variable which is rare on vent hoods. This means that they both function like a rheostat with a continuous increase, or decrease, rather than clicking up or down discreet notches, such as level 1 to 4. Also, I liked having the option of installing the switches wherever I wanted remotely, rather than being mounted to the underside of the hood. The hood easily handles removal of odors, steam or grease beneath it's surface. I've found that if the hood is allowed to run for about 10 minutes prior to cooking that it can be operated at a lower level and do a good job. The hood on low is fairly quiet but is noisier than I had anticipated at higher levels with having dual fans and baffles. Also, highest cfm level is 1000 which is a factor. However, I used a different size led bulb than Imperial recommended. I now have a gap around the bulb that needs to be filled with a rubber gasket. Also, the temporary roof jack is too large, and the correct one is waiting to be installed so the jury is still out on the noise issue. Noise level was quite an issue for me, but even if it remains unchanged, I would still buy the same hood given how pleased I am with the overall operation and that I can easily live with the noise that I now have. I'll have to look up the name of the online vendor I used and will add that information tonight.

You would have to wire it to a 240 Vac circuit (two breaker poles) and hope that the motor, designed for 50 Hz in the EU, has no problem at 60 Hz in the US. Higher frequency is often easier on the magnetics, but this should be examined. If the motor is of Japanese manufacture, it likely is designed to operate at both frequencies, as Japan has half the country at 50 Hz and the other half at 60 Hz.

Well, I can be long and rambly too, and suggest reviewing the many hood threads here to see that demonstrated. I can also suggest that if you, @Margaret Davis, do so, you will learn a lot more about both hood requirements and make-up air (MUA) requirements. I'll supplement the information on this site, first by noting my astonishment that whoever wrote that blurb for Proline seems to be missing the most fundamental concept -- no air leaves the kitchen that doesn't get replaced. No reports of imploded houses due to hood blowers pulling a vacuum have ever come to my notice. With respect to the requirement that outgoing air be matched by incoming air, the size of the kitchen is irrelevant. The blower size is irrelevant. How long you run your hood is irrelevant. There is always a balance such that the actual hood duct airflow matches what leaks into the house, or is allowed to flow into the house, or is deliberately blown into the house. Gag the MUA, and the house interior pressure drops until the hood blower volumetric flow rate matches what can leak in at that pressure drop. The controlling aspect is the 'fan curve' of the hood blower when MUA is passive (not blown) and the combination of fan curves when the MUA is active (blown). Example fan curve [click to enlarge] Broan 1200 CFM blower fan curve. The pressure that determines where one can operate on the fan curve is determined by pressure loss passing the hood baffles, the ducting, the exterior cap if not included in the fan curve, and the MUA pressure loss getting air back into the kitchen. With a large diameter passive MUA or imperfectly tuned active MUA, you are likely to see the actual hood air flow to be only 2/3 of the zero static pressure flow rate, that is, 2/3 of 1200 or 800 CFM. Modern codes require, as @Celedon noted, deliberate (active or passive) MUA when the hood rated blower size (not actual flow rate) exceeds 400 CFM. This is to ensure that any combustion appliances that are present, or may be present in the future, are not back-drafted by negative house pressure thereby introducing carbon monoxide into the house. Second, I won't go into hood requirements here as those should be easily found among the hood threads, and in any case you seem to have picked a hood or hood size. However, I will address the vertical duct question. Generally, the highest pressure losses will be the hood baffles and the MUA if passive, depending on duct size and filtering. So longer ducts will drop the overall flow, but perhaps not too much relative to these causes. This can be evaluated by plugging the duct parameters into on-line calculators that may be found by searching. Third, most ventilation noise is air turbulence noise, dominated by that at the blade tips of the blower. Duct turbulence will also contribute. Silencers reduce this, and may (as in the case for me) reduce the noise such that baffle turbulence (hiss) dominates. An advantage of running the duct into the attic would be that in the attic there may be room for a silencer to be inserted between the external blower and the hood. One can also angle the ducting there so that the external blower is at an advantageous point on the roof. No matter what tortuous path you choose, and the ducts you have sketched aren't really that long, be sure that the chase allows access to the ducting in case cleaning is needed (usually rare in residential cooking). In cold climates it is best to keep the duct warm over as much length as possible, so exterior ducting may want to be in a chase if very long. With a larger chase, a silencer can be put closer to the hood, which helps suppress duct noise. Fire protection in the chase may be an issue; discuss with your code enforcement officer. You should plan on using at least 10-inch ducting, but note that the Fantech 10-inch duct silencer is 14 inches in diameter by 3 ft long.

There are on-line calculators for various duct sizes and lengths. But for initial "just how bad is this" questions, there is an approximation from IRC Table M1506.2. This is that the equivalent circular duct diameter for a non-circular duct equals { 4 times the sectional area divided by the perimeter }. One can examine the limits of this equation for weird ducts and see that it might break down for cases no one would use, but it is the best I know of without detailed flow analysis. Note that transition loss from one shape to another will be significant and I don't know if there are any data repositories for the numberless cases one might conceive. A real HVAC engineer may know of such.