Most of the range hoods I've seen don't make sense, I realize now. I once liked the sexiness of curved glass range hoods with inner stainless block, like this one
though I have only been looking at the wall mount kind, to replace my fake (no exhaust) system.
But the capture area of such a hood is determined by the inner metal part. The glass doesn't help much in capture, by the time the smoke or steam rises there it is probably lost, unless the fan is blowing harder than necessary. What counts is more approximately the area directly horizontal from the air inlets, and not too far out from the last air inlet in any dimension. Or, if the center is raised, capture area extends as far as the sides continue lowering.
Capture area is what you want to maximize with a range hood. For efficient capture of the steam and odors, building scientists have determined that you need a hood at least as large as the cooking area, and increased 6" for each 30 inches of rise above the cooking area.
Conventional electric cooktops end around 22 inches from the wall (this specification is remarkably hard to find, and I'm guessing) and this is the spec that matters for range hood depth, because it shows to meet an efficient capture area a hood at 30 inches above cooktop should be 28 inches deep. I have not seen that, though I do sometimes see hoods at 25 inches or so deep, called "professional" and having very hard to meet residentially 1000 cfm or higher.
There's been a kind of horsepower race in big ranges and range hoods, where the sellers of these things push people to large sizes ("everybody does it now", the familiar self-fufilling claim) so people feel inadequate without the latest 2000 cfm or higher for their 48" range. (Meanwhile, lifelong cooks for large families say a 30 inch range is entirely adequate...)
If you have a range hood higher than about 100cfm/1000sqft of house space, some say (actually there is a code on this now, and I'm not exactly sure what it says, but possibly something like this) you need to explicitly provide make up air. And this is still sometimes not done (though less often than before thanks to the code change in 2009).
Anyways, not only do you need makeup air, but it's expensive, so you don't want an unnecessarily powerful fan.
And to get the most clearance of cooking smoke and smells, you can do it one of two ways:
1) have the proper sized hood (as described above, quite deep, in fact unobtainium in residential equipment) combined with the rule-of-thumb sized fan, for example, 10cfm per inch of electric cooktop width (it's a btu number for gas). So for my 30 inch wide wide range I need (or would need) 300cfm blower (which means I'd need makeup air, but not too difficult with 8 inch dampered duct).
Oh, and optimal hood also includes being 6" wider on both sides, so the hood should be 42" wide in my case...
2) Have an undersized hood, and a stronger blower fan. Well of course this is what everybody actually does, and for those that don't bother with such nicieties (and code requirements now) as makeup air, they aren't getting the nameplate cfm anyway, as the house turns to vacuum state and crud rushes in from everywhere.
The typical range hood is 17 inches deep, way inadequate even for electric, very inadequate for gas.
Well I may get get a 22 inch deep Broan Evolution 4 hood anyway, with 440 nameplate CFM hood (and you gotta look for the vertical 7" shaft number...the fan above is actually advertised as 600 cfm, but that's with a particular large rectangular duct only...another form of specification inflation). I could possibly get by with the Evolution 3 and 330 CFM.
With 440 (instead of 300) CFM, the lack of proper depth and sides is somewhat compensated for, without going overboard. Anything larger than the above would be way overboard. I haven't seen reasonably sized fans or designs above 22 inches deep so far. Also, the hood has to be raised to allow for taller people, especially as the hood gets deeper than 22 inches.
Perhaps a blank slate hood would be 34 inches deep, 7 feet high. Such a large hood could actually use lower CFM than a typical system, and work as well.
And I'm doing the fan-sensor controlled makeup air system with controlled duct, and outlet hopefully above the refrigerator. Cold air will sink onto the warm refrigerator coils, hot air will stay around the ceiling. Muchly. And it makes sense for the gain or loss to be felt in the kitchen, where the source of the problems is, and the operator can make needed adjustments if going too far overboard.
As long as it doesn't get too cold outside (combined with cooking in the early AM) make up air dumped above the refrigerator should be no big deal. BTW, otherwise the kitchen is heated to 75 degrees as the rest of the house in my case. If there were not such general heating/cooling, the makeup air dump there could be more of an issue...and would have to be relocated to some other place chosen to cause the least discomfort...bedrooms and bathrooms worst, living room(s) best.
Generally, in a fully designed system there is balanced ventilation, with fresh air routed to the central system, and continuous exhaust in bathrooms (I suggest also the attached garage have it's own continuous exhaust, which is what I do). And the ultimate would use something like ERV to obtain energy efficiently, so indoor air temperature is less compromised by the inlet of outdoor air, which can range from far too hot to far too cold.
That cost...the cost of loss of good climate control...is the cost of using too big a range hood fan, ultimately the biggest cost (well, without makeup air, if you had unvented gas appliances, the occupants could suffer with CO poisoning and such...but after those serious errors, the loss of interior comfort is the greatest reason for designing the range hood right and not using too much exhaust flow.