Downdraft ventilation is well known to perform poorly at capturing cooking effluents. I suspect that recessed “hood”...and I use that term loosely...will be even more inefficient.

Perhaps our resident ventilation expert, @kaseki, will pipe in...

They are both really awful choices. Cooking only occupies 10% of your kitchen time. Putting it in the middle of a view is just a terrible idea. Relocate it, so you can enjoy the view while at the island, prepping, which is 70% of your time. If you try to pay attention to it while you are cooking, you’ll either burn yourself or mess up the food. For 10% of the time in the kitchen.

Post your layout. You gotta fix that bad design.

This one has the skylights drawn in for lighting design purposes. There will also be an island on wheels that will usually live in the center and be the primary prep area. Also, the back door is the primary access to the house. There's a ton of traffic through the kitchen so we didn't want the range to be on that side since we want it to primarily be a walkway. Past the peninsula is the dining room.

Hard to find two different ventilation approaches that deviate so much from the efficient performance achieved by (and demanded from) commercial hoods.

Downdraft Pop-ups. These cannot flow much air and cannot capture effluent except that which rises next to their tiny intake vents. If the greasiest food to be cooked is slowly simmering bacon on a back burner, then they might be functional. And in the illustration, the downdraft is narrower than the cooktop, violating the required function of capturing rising and expanding cooking plumes.

Ceiling registers. Even those that provide filtering over their entire area have a few issues. First, the plume expansion, along with the effects of drafts, requires the ceiling area used for capture to be large, at least a foot wider and deeper than the cooktop. Airflow requirements, and make-up air requirements, will demand a large CFM blower for each. The particular design shown seems to have metal plates with slots at the edges. This should be good for added noise, and higher velocity plumes may easily reflect from the flat areas and thence out of the effective capture area of the slots. The mesh version should be chosen. Cleaning could be difficult. Cooler plumes at the ceiling might affect how much grease condenses where -- I have no data. Commercial ceiling ventilation such as Haydahl supplies http://www.kitchen-ventilation.co.uk/heydal generally cover large areas and have specialized grease containment or destruction schemes.

Opinion. If my only two choices were the ones proposed by the OP, I would be forced to go with the ceiling vent, only because that is where the cooking plumes will go no matter what the pop-up attempts to achieve. I would use a pair of the largest mesh units, tied to suitable ducts and blowers, or maybe joined into a 14 inch duct with a roof mounted up-blast blower. If attic room allowed, I would use a compatible Fantech silencer to go with the roof blower. A largish passive or active MUA system would also be needed.

Flow velocity measured below the ceiling should be at least 60 ft/min, assuming some cooling of the plumes, 90 otherwise. So multiply 60 times the areas of two 63 x 27 inch units and get 24 square ft x 60 = 1400 CFM actual. Zero static pressure blower rating would have to be in the 1800 CFM range, depending on the blower's fan curve, the mesh filter pressure loss, duct pressure loss, and imperfect MUA pressure loss.

We are well aware of the cost, but the view is worth it.

The sink is right next to the dishwasher, across from the refrigerator, and next to the range. Isn't that the definition of a cooking triangle?

Most of the prep will be done on a rolling island that isn't pictured but will live in the center. We like to keep the 90" peninsula as clear as possible, there are bar stools there and people like to hang out and snack there. If the range were to be moved to the peninsula then we would still be looking at downdraft or recessed hoods because it's a very open layout where you can see from the kitchen all the way to the TV in the living room and we would like to keep it that way.

You’re not understanding kitchen work zone theory, or mis en place zoning.

It is not a good design for cooking. It will be difficult to work in, and a nightmare to clean. Its a ton of money to spend on something so dysfunctional.

If the view is that spectacular, then the range needs to move. Period. That’s an A or B scenario that you can’t ignore. Choose an unencumbered view, or a blocked view from cooking and steam and potential broken glass because of incorrect safety measures being taken. 6” minimum clearance to the rear wall, plus safety glass, and no protruding trim or blinds or any of that. Ever.

You want at least 36” between the sink and range, as that’s your primary prep zone. Prep occurs next to water as the first natural motion. It’s unnatural to prep elsewhere without water access, but humans can force themselves to adapt. Adding prep sinks and hand washing sinks to a kitchen is the next big explosion in kitchen design, prompted by the renewed interest in the health benefits of washing your hands. And making it easy to wash your hands. Which is why prep actions naturally occurs next to water. Anyone with the proper habits of washing their hands throughout food preparation wants that ease of access of water adjacency. Which is why the lonesome bar sink away from the action is a useless expense, unless it’s to fill a coffee maker.

I have had a downdraft hood, and suspect that since yours will be a simple run directly out the kitchen wall you will have no issues with effectiveness. I'd rather have that then the steam and grease being pulled all the way up to the ceiling.

Oh, look at all the incorrectly designed fire hazards. 🙄 Just what everyone needs to emulate. Badly designed pictures aren’t helping any argument in favor of any positives of having a cooking zone in front of a window. It does the exact opposite.

holy crap, that second picture with the window ledge extending over the cooktop! 0.o

isn't the best approach to range + window to have a window that opens? using that for ventilation instead of/in addition to any kind of vent? people have done that for years, and I've even seen it discussed here (although I'm sure live_wire is right that you need to add 6" to that entire counter run in order to get a safe distance from the glass. even glass backsplashes often end up cracking).

Given that prep time generally exceeds cooking time, more view time would result from establishing a prep zone at the window, and moving the cooktop or range to a fixed island, with proper island hood. It would also reduce potential greasing of the window.

Beverly: Hoods don't do much pulling except very close to their entry aperture. They depend on the cooking plume momentum to bring the effluent to the entry aperture. Gas fired cooking plumes have been measured with upward velocity of 1.2 m/s. I find it highly unlikely that a downdraft aperture on the stove or next to it could reverse that velocity toward the downward direction, as it would need to do so several aperture dimension lengths away from its aperture [also without interfering with the gas jets].

I don’t know about anyone else, but when I’m prepping or cooking, I’m not looking out the window. Rather, I’m paying attention to what I’m cutting/chopping, while I prep. And, at the rangetop, I’m watching what’s in the pan or pot, while I stir, or add ingredients. It’s called, safety.

Our best views are reserved for the dining nook. That’s where we can enjoy the outdoor scenery, and linger.

Beverly:

(a) All videos using low-velocity steam as a demonstration only show performance against steam.

(b) Schlieren photography (that the video called shadow photography), is the best means of analysis, but close observation of the imagery you linked shows plume portions missing the downdraft (or side-draft, as it were). And this plume was not a caramelizing wok cooking plume, a steak searing plume, or a grilling plume.

This is not to suggest that I think this approach is wrong for everyone; but the capture performance will be limited to lower velocity plumes. If this is an acceptable compromise to the user, then the cabinetry and house structure will need to be integrated with the mechanical aspects of the pop-up design.

To capture and contain a 1.2 m/s plume rising vertically, the air flow from the vent aperture measured at the plume location would have to be of the order of a meter/second, and this requires (per ref. below) a velocity at the aperture many times higher. (Velocity drops to 10% of the mouth velocity a mere 160% of mouth small dimension (height) away from the mouth.) I believe that achieving such a velocity at the distance to the center of a front burner plume would require an extremely powerful and noisy blower.

Ref: Figure 6, page 30.4, 2003 ASHRAE Handbook, HVAC Applications.

Thank you for linking the video.

To the OP: Care must be taken to conform with fire codes, particularly a gas cooktop or range's off set distance from flammable material within a certain distance, Intermediate non-flammable materials may not reduce these distances unless conforming to the IMC. If I recall correctly, live-wire-oak has published the most on this in this forum. The pop-up might, due to its nature, achieve the necessary barrier performance. Consult with your Code Enforcement Officer.