I think kaseki meant the aperture as being the grill area. So for a my 48" x 27" wolf pro hood the actual aperture is 45" x 12". You may want to readjust your calculations. Basically your aperture would be around 33" x 12" or so. The duct run you describe will allow you to place a rooftop ventilator. Couple that with a fantech silencer and you will definitely shed some noise. The nice thing about the wolf range hoods are the infinite speed control so even if you go overkill with the blower (you know you want 1500cfm just in case!) you don't have to use the full 1500cfm but if you decide to turn your stove into an indoor barbeque pit you have the ventilation. makeup air is another tricky question..You have to see if the building inspector requires an actual official solution . It gets even trickier if you need to heat the incoming air.

If not you can try getting a remote operator for a nearby large window (truth hardware makes them) and either manually remember to open the window or wire it so when the hood fan turns on the window opens .

Actually, by aperture I meant the opening at the bottom of the hood that intercepts the rising and expanding effluent. The hood may be a bit bigger than this aperture. I believe this meaning is also relevant to Greenheck's use of a 85 CFM/sq. ft. value for certain types of cooking. (Many commercial hoods have thin edges.) Schlieren photography of successful and unsuccessful capture arguably puts the specific flow rate into this range.

In some cases where the hood has a flush bottom with mesh filters, some effluent won't be captured due to reflection unless an extreme air flow is achieved, and for such cases reasonableness suggests using the area of the meshes and their close surrounds rather than the entire hood area. It is also true that at an actual 90 CFM/sq. ft., there will be a modest zone of a couple of inches around the hood where passing plume effluent may be captured.

Further, baffle designs vary somewhat, and different shaped approaches to the baffles can exist, particularly in commercial hoods. For my Wolf Pro Island hood, the baffle area (mapped onto a horizontal plane) is essentially equal to the inside area of the hood at the base.

And just to make this more complex, the actual plumes have different velocities with angle, and with pan temperature, and with presence or lack thereof of hot combustion products. So, in some cases with a large hood providing good capture, less than 90 CFM/sq. ft. may be sufficient, perhaps as low as 60 if using induction, or if no wokking or searing is attempted.

And then the value of 1.5X can be debated depending on duct characteristics, losses in baffles and hood, the blower's fan curve, and whether the MUA is pressurized so that the house pressure is very close to equaling the exterior pressure.

And last, the calculation leading to 1000 CFM for the blower zero-static-pressure rating implies an actual flow rate given various pressure losses of 600 to 700 CFM, not a particularly extravagant value.

So, my suggestion is intended to be an estimate that covers a lot of sins and uncertainties, and which should lead to few complaints about inadequacy. I will not be inspecting your system and handing out black marks for non-conformance, so feel free to juggle the trades between performance, aesthetics, and affordability.

When composing a message here, one can do it in a text editor and paste it into the composition window; this might have merit if one has dropouts that cause loss of one's creative effort. Also, one can write in the window and edit to his heart's content, and even change his mind and remove the entire text, then drop the page without submitting. As we aren't allowed html, and extended character sets aren't certain to work, I'm unclear on what advantage results from previewing beyond that which occurs as we write.

A 27" deep hood is more difficult to find, and expensive. I think you will be fine with a 24" deep hood.

1000 cfms seems a lot, until you said you plan on searing steaks and stir-frying. I get the impression those are frequent, and in that case 1000 cfms is appropriate. If you said you sear steaks just once a month for example, you could have fewer cfms. But keep in mind that it is more flexible and quieter to be able to turn down the power on a 1000 cfm hood, than to have a 600 cfm hood have to be on full strength all the time.

You mentioned the ductwork - don't overlook the size of the duct diameter from the hood. It needs to be 8" or 10" diameter depending on what hood you buy; the hood's specs will tell you. Do not get a duct smaller than what is spec'd, or else you will have a noisy, less effective hood.

"Distance from stove top to hood has not been decided yet."

It should be 30"-36" from the top of the cooktop to the bottom of the hood. Lower than that, and it will look and feel cramped. Higher than that, and there is more opportunity for effluent to escape the hood exhaust.

I'm from WA too.

We did our own remodel (with permits) and found that calling the building inspector was helpful when we had questions about MUA. They will let you know how many CFMs they will allow without Make Up Air. In our setup we were allowed 600 CFMs without MUA. The inspector gave us some ideas about how and where we could do MUA. In addition to causing static pressure without make up air, he told us that with very high CFMs pull air out of places not wanted, like fireplaces or worse.

You've got a really good idea, to figure out what you want and get it into the plan at the beginning. Trying to fit in MUA at the end is more complicated.

Thank you all for the feedback.

Kaseki, thank you for clarifying the meaning of aperture.

"...you said you plan on searing steaks and stir-frying. I get the impression those are frequent..." It's fallen off, but last winter steak my wife cooked steak once a week. Stir-fries are my thing, and I cook infrequently, so they are rare.

Looking at hoods and make-up air prices I’m coming to the conclusion that I’ve got Cadillac tastes and a Yugo budget.

House was built in 1940. Sealed she ain't.