Prestige has a vent--shelf. It comes in 24, 30 & 36". There is an electrical outlet on the shelf. You can put any microwave that is less than 20" deep on the shelf. It has a 600 cfm blower with baffle filters and removes smoke, grease and order directly from the cooking surface. It can be ducted or ductless and was designed for putting microwaves over pro ranges. prestige-america.com

How air tight is your home? The more air tight the home, the more energy efficient and this means that mechanical devices need to bring in make-up air rather than relying on a leaky building envelope. A big powerful kitchen fan will expel a lot of air. When you expel air then your house needs to replenish that air, which means pulling in outside air through the cracks. Expelling heated/cooled air and replacing it with unconditioned air is not free of expense. Keep this issue in mind and think of the whole house rather than just the fan and design the house for the fan, or vice versa,

OK, lets go at it piecemeal. What is the width of the range? Is it electric coil, gas, or induction? If installed, or if there is a fixed installation plan, what is the spacing of the upper cabinets on the sides of the range? With respect to air flow: There are several commonly used rules of thumb, one of which is based on total potential BTUs. The BTU method is an indirect method of estimation of needed flow rate, and doesn't account for how well the hood overlaps the range. I prefer the more physical approach based on the needs of capture and containment (what hoods are supposed to do). Capture efficiency depend on how well the hood aperture overlaps the rising and expanding cooking plume (effluent). Containment efficiency is determined by how well the hood air flow through its baffles (or mesh filters) keeps the plume from reflecting out of the hood when it hits the sheet metal baffles or mesh structures. A generally sufficient air velocity is 90 ft/min for gas cooking; induction cooking may allow one to get away with a bit less as it doesn't have a gas combustion plume adding velocity to the cooking plume. Electric coil plume velocities may be in between; the lab measurements that I've seen published don't include coil cooking measurements. (Gas cooking can cause the central part of the rising plume to reach 1.2 m/s.) The necessary air velocity has to exist over the entire hood aperture; we don't get to block off portions of the aperture that we are not cooking under. The aperture has some area -- more if there is good overlap of the plume expansion. Hence I suggest 90 CFM/square foot of aperture to get 90 ft/min everywhere. (You may notice that this is about half of the uprising velocity. We don't need to equal it, only keep it from reversing while the baffle aerodynamics take control of it. Baffle design and mesh flow effects may vary how well a given average air velocity works. I know that around 90 ft/min works for me when induction wok cooking, and that Greenheck suggests for similar cooking a value of 85 ft/min for their commercial hoods. There are types of commercial cooking that call for considerably more velocity, such as grilling, but this is not in the scope of our present discussion.) Ideally, to get good capture to make use of this containment, the hood has to overlap the locus of hot pan bases by about 10 degrees half angle. From this another rule of thumb has arisen that suggests overlapping the cooktop by 3 inches on the sides and front. This overlap is probably too optimistic for some searing or wokking, but many here have reported good capture with this size. For a 30-inch range, this would require a 36-inch wide by 27-inch deep hood. You may not have room for this, or you may wish to depend on the side cabinets to channel the effluent from rear burners and cook the greasiest stuff there. So for a 30-inch range, the minimum hood would probably be 30 inches wide by 24 inches deep (front to back). I suspect for most 20 inches deep is too short. As you may appreciate, the larger hood thus has higher total air flow requirements than the smaller hood, costs more, and requires more make-up air. So you may also appreciate that this aspect of performance alone is in conflict with affordability for a given level of aesthetic design. Wait until we get into make-up air issues. kas

Hello Houzz Community! I found this thread when Googling a similar topic. I'd like to replace my under cabinet hood with a wall mounted hood, and yes I know I have to remove the cabinet above the current hood which I'm fine with (see photo). My existing under cabinet hood vents out the wall to the side of my house - see photo, and note the vent is not blocked by those shrubs, there is space around it, you just can't tell from the angle of the photo :-) So my question is....can a wall mounted hood be installed to vent out the existing vent in the wall, or does a vent need to be created in the ceiling? Also, what type of professional can help answer any related questions I have about this? Would I ask the wall mounted vent manufacturer? Or a handyman? Thank you in advance for any guidance! I am a newbie homeowner and am learning as I go, so truly appreciate you taking the time to share your knowledge with me!