Hello all... I'm having trouble finding a photo of this kind of hood treatment... a simple 18" high pro hood with a wood duct cover going the full width of the hood (and up to the ceiling). I know I used to have a c.2005 or so Wolf range brochure that had a 60" range with this kind of hood, but it's long gone to the recycle bin. Shame on me. Ironically, I once saw the exact same kitchen with a Viking range in it's place in an ad for Viking. The wood duct cover I am thinking of has no detail to disguise it as cabinets, although it matches the cabinets. But really, any photo you might be able to think of with this kind of thing would be great! Thanks.

The hood is Bluestar/Prestige Pro-Line, 36" wide (over 30" range). It has baffle filters, variable speed 1200 CFM blower (you can get a 600 too), and dimmable halogen lights. It is 24" deep. I LOVE the hood, it is excellent. The design is seamless and the stainless and finish are really nice. The design is great too because the lights are in the center: right where you need them over the stove and then the capture area comes right to the front of the hood. Purchased from Eurostoves with no trouble at all and a good price, especially for the upgraded blower. Trevor also has an excellent knowledge of ventilation. I saw this treatment of a duct cover, including the crown moulding, in a book called The New Bungalow Kitchen. It was in a 1920 - 1930 style kitchen and when I saw it I knew it was exactly what I wanted. The crown moulding runs all around the kitchen, above all the cabinets too. Although I used the wall color, the wall color is very close to my cabinet color. I like the wall color in this case because I have no cabinets next to the range and also it gives the feeling that the vent hood is sort of floating/hanging in the air. I think it makes it look less bulky and imposing that way. Anyway, apart from that book I have never seen another kitchen done with the hood this way. Perhaps we are starting a trend! Much cheaper than a stainless cover too!

To be even slightly informed about this subject, you would have to read quite a few hood and make-up air (MUA) related threads on this forum. We could also point you to commercial literature that one might extrapolate from. I can provide a somewhat standard spiel touching on the highlights. I cannot provide reviews of hoods I haven't owned. There are two maxims that one might keep in mind. (a) Performance, aesthetics, affordable cost -- pick two. (b) The most efficient hoods (cooking plume capture and containment performance per watt of electricity usage) are commercial hoods. For an idea of commercial hood design and function, read the first dozen pages of the Greenheck Guide, available from: https://www.tagengineering.ca/wp-content/uploads/2015/02/KVSApplDesign_catalog.pdf. What a hood system is expected to accomplish is capture and containment. Capture is effected by having a hood canopy that overlaps the rising and expanding cooking effluent plumes so that these plumes pass into the hood volume, preferably under their own power. Containment is effected by pulling the plumes through the hood filter system -- preferably baffles for most serious hoods -- and thence via the ducting to the outside. Containment requires adequate volumetric flow rate (CFM in the USA). Flow rate achieved depends on the blower selected and the pressure losses moving air through the baffles, through the hood, through the ducting, and through the roof or wall cap to outside, and then, most importantly, the pressure losses in getting fresh outside air back into the kitchen (MUA). Flow rate required depends on the velocity of the cooking plumes and the area of the hood entry aperture. Obviously, one wants the achieved flow rate to equal the required flow rate. But wait, there's more: The specified flow rate for blowers is that achieved at zero pressure loss. The flow rate at some pressure loss is less, just like strangling a water hose decreases water flow. One has to specify a blower strong enough that for the conditions present the desired flow rate can be achieved. (Not otherwise addressed here are the desirable hood features of lighting and blower control.) Fortunately, in many cases we can apply rules of thumb to the selection criteria. Some arithmetic is required. Overlap the hood by at least 3 inches relative to the cooktop or range top on all sides not including a wall. For a 24 inch [front-to-back] range, achieving a 27 inch wall hood may be difficult or interfere with sight lines or head position; in such a case a 21 or 24 inch hood front-to-back depth may do with some plume escape possible. Calculate the area of the hood aperture in square feet and multiply by 90 ft/min to find desired CFM. Multiply that result by 1.5 to roughly find a specified CFM that should work. Choose a duct diameter per the hood installation directions, but the goal is an air velocity in the duct between 1000 and 2000 ft/min. This equals the desired CFM divided by the duct sectional area in sq. ft. Choose duct paths that minimize length and bends, but these are not prohibited. MUA is an entire topic by itself. The goal is to allow air to get from the outside to the kitchen, heated or not depending on circumstances, and lightly filtered, such that the pressure loss from outside to inside is low. In some cases, this may require a blower in the MUA duct. Many simple configurations are possible, along with more complex ones. Search out MUA threads here. Overall, the hood and MUA systems can reach the same price as a high-end range price, and easily exceed the price of an economical induction cooktop.

The hood needs to encompass and trap the rising and expanding cooking plumes. The capture only works if the hood is large enough, and has a means to block escape of the plumes. In the example I commented on, the only intake area is the small (meshed?) zone in the middle, and that is raised relative to the cylindrical shaped part, reducing any side-slip of a plume portion into the mesh area. Otherwise, rising plumes blocked by the cylindrical section either reflect out immediately or slide toward the top where they slide out the front or back area. Some hits the mesh and is pulled in, and some close to the mesh is pulled in. At a minimum that shape would have to be a spherical section and larger. Fundamental rule: The closer a residential hood conforms to a commercial hood, the more fully and efficiently it will perform its main functions of capture and containment. Second fundamental rule: Hoods do not suck up plumes from the cooktop; they make use of the plumes' momenta to bring the plume to the hood where it can then be entrained into the air flow created by the hood or duct system blower. Third fundamental rule: No air leaves via the hood that can't be replaced via some method of make-up air (MUA), either house leakage, a passive duct, or an MUA blower system. So, in addition to the Hood FAQ, it may be useful to also review the first dozen pages or so of the Greenheck Guide available at: https://www.tagengineering.ca/wp-content/uploads/2015/02/KVSApplDesign_catalog.pdf