Baffle filters, which I believe started in commercial kitchen systems, have the property that they can collect (liquid) grease almost indefinitely without significantly changing the pressure drop across them. Mesh filters more easily clog due to lint collection along with the grease. Most people, I hope, would want to clean either type long before the pressure difference became apparent. Whether a particular mesh filter is as good as a particular baffle filter or vice versa would require the manufacturers to publish the graphs showing percent capture by particulate diameter. Some commercial baffle hoods and some retrofit filter replacement manufacturers report such data, and it might be possible to infer performance for a given mesh filter from a study of the reports. Also, performance of baffles as grease collectors is dependent on air velocity, so a little more engineering is required to be sure the baffles are operated in their "happy" zone. This is normally achieved by following manufacturers' instructions on flow rate requirements. kas

There is no single filter type that collects aerosol grease particles of all sizes within the particle spectrum generated by cooking (possibly excluding intense UV conversion of grease to gases.) One can tour on-line advertisements for commercial filters and see what part of the particle spectrum they are designed for and how well they work over part of the spectrum. What you hope for in a residential hood is that you collect the larger particles in the filter and the smaller particles exit the ducting before they can condense on the ducting. The result will always be imperfect relative to the goal. Deposition depends on what sizes pass the filter (baffles or mesh, usually) and the velocity of the air in the ducting, and the temperature of the ducting. Note that Magic Lung centrifugal grease slinging is not that different from how baffles work to collect grease. Like baffles, the Magic Lung squirrel cage fan can only impinge the larger particles against the assembly wall. The fine ones stay as an aerosol in the air flow and are passed up the duct. kas

Kobe makes all kinds of them - https://www.thenaturalhome.com/stainlesssteel.htm#wallmount

A few points. If the room volume of air is expelled in T minutes, then in T minutes the odor and grease (not yet deposited) will have been diluted to 1/e of its initial level. The dilution is exponential. e = 2.718... Another 1/e dilution occurs in the next T minutes. frazzlehead: Blowers are rated at zero static pressure -- hanging in free air. When attached to a hood, even with no ducting and open unscreened windows, there will be a pressure loss in the hood due to baffles or filter meshes, and due to abrupt transitions in the sheet metal. The pressure loss determines the blower's actual volumetric flow rate, and this is documented on the blower's "fan curve." Example fan curves may be found at Fantech's site and at Broan's site. A hood's primary two functions are capture and containment. Capture requires that the hood overlap the rising and expanding cooking plumes from the pots and pans. (More precisely, it requires the hood to overlap the higher velocity plume components such that the wider angle lower velocity components are entrained into the hood air as it passes over the cooktop.) Containment requires that the air velocity at the hood's filters and over various sheet metal parts on the cooktop side of the filters be high enough that when a plume portion strikes one of these components, the plume effluent continues to the filter and is pulled past the filter. The air velocity needed depends on the plume velocity and various other fluid dynamics details. For an induction cooktop performing high temperature cooking such as wokking or searing, the plume velocity is in the vicinity of 2 ft/s. The velocity in a baffle gap is probably twice the blower induced air velocity, so lets assume 1 ft/s is needed over the entire hood entry area. For a 3 ft x 2 ft hood entry aperture (6 sq. ft.), 1 ft/s = 60 ft/min requiring 60 CFM/sq. ft. or 360 CFM actual flow. For lower temperature cooking, lower velocities should be sufficient. For a hood, duct, screened open window configuration, I would want at least a 540 CFM rated blower. Less will work with more modest cooking. Note that even simmering bacon with a very low plume velocity requires some significant flow rate or else baffle filters will not perform centrifugal extraction of grease. In such is the limiting case, mesh filters may be better. In all other cases involving significant cooking temperatures and plume volumes, baffles are better. The best hood configurations are commercial configurations, because maximization of performance for electrical cost dominates commercial kitchen ventilation trades. Residential hood configurations that carry over some aspects of commercial configurations are better than those that don't. However, for very low flow rate needs, it probably doesn't matter much whether chimney or under cabinet. Just be aware that a future home buyer may have a different cooking style, and may possibly appreciate his needed expense of upgrading. In summary, better is the enemy of good enough, but good enough is the enemy of long term planning.