Keep in mind that a large component of a hood's noise is the ductwork. The duct that goes from the hood to the outside of the house needs to be 8" or 10" diameter. If your duct is too small for your hood's cfms, you will have a noisy hood even if the hood is billed to be the quietest hood in the universe.

In addition, people have unrealistic expectations of hood noise. It is a motor, hung near head height. It is going to be noisy. Think about your bathroom exhaust fan. Those are typically 85-100 cfms. How noisy is it? Your kitchen hood will be about 5x those cfms.

For the quietest hood, you would need to install a "remote blower". That is where the motor is mounted on the home's roof, rather than directly at head height. It is expensive.

Except for bearing noise in the blower fan motor, most hood system noise is due to air turbulence. Turbulence sources include the fast-moving fan blade tips, the baffles, ducts, and hood internal transitions. The dominant noise is usually the blade--tip turbulence, so it helps to move the fan to the exterior of the house, so long as the duct is fairly long. Further improvement, and perhaps the most important in this simple configuration, is adding a silencer to the duct path between hood and blower.

No manufacturer is likely to build baffle shapes that are low noise unless a simple effective shape is discovered that also performs its function of centrifugal collection of grease particulates. In other words, no NACA air foil shapes will be provided.

It is possible with an external or in-line blower to choose a more powerful model and run it slower. This may preclude the need for a silencer.

A well configured but still residential grade system can reduce noise to baffle hiss at a conversational level, given that the air flow velocity over the area of the hood entry aperture meets containment requirements.

Think about your bathroom exhaust fan. Those are typically 85-100 cfms. How noisy is it?

Not a good example... Our Panasonic bathroom fans are so quiet I often have a hard time telling whether they are running.

On the other hand, there is absolutely no doubt whether the kitchen vent hood is running. We did the best we could with keeping noise levels low. But the particular constraints of our building precluded things such as a remote blower or a silencer. So, we just have to live with the noise.

My favorite hoods are by Vent-a-Hood. I have used them on many projects. Here is the link to the specs regarding their efficiency and noise level. https://www.ventahood.com/index.php/about/innovation/magic-lung

Except Vent-A-Hoods are a PITA to clean. Make sure if you are considering that brand that you go someplace where they are on display, and ask to see how they are taken apart for cleaning. It’s not like just pulling out your hood’s baffle filters and sticking them in the dishwasher.

We have a Vent A Hood, and don’t find it a pain to clean. And, it’s much, much quieter than a baffle hood. It does a great job. Also, the way Vent A Hoods are constructed, you can go with fewer CFMs than other hoods, which affects how much make up air you’ll need.

M...we also have Panasonic bathroom fans, and find them extremely quiet, and powerful.

Back to the Vent A Hood...ours is vented externally, which helps greatly with the noise factor.

Here’s ours:

I'm trying to to select the quietest and most efficient hood/blower set up for a 48" blue star gas range top. I'm looking at the Prizer 52"W insert to be housed in a wall mounted wood hood. One of the appliance representatives has told me that if something goes wrong with the remote blower mounted on a slanted roof that some repairmen will not service it. Does this make sense? Couldn't one access it through the attic? (Our attic access is <15 feet from the wall where the hood will be mounted) We live in a 2 story house in the South (We're not on the coast, so we do have a winter but not much precipitation) with the kitchen on the second floor. The hood will be mounted on an outside wall overlooking the flat part of the driveway(the remainder of the driveway is steep, but we've had delivery trucks get up and down the driveway without problems).

The appliance representative we're working with thinks the Vent-a-hood magic lung would be the way to go as far as quietness, and that I wouldn't need an inline silencer or remote mounted blower with it. I've not read enough that I'm convinced it's the quietest option. Your thoughts?

I really find the baffle filters appealing for ease of cleaning and the fact that per specs of the Vent-a-hood liner, it cannot be mounted higher than 30 " above the cooktop. Neither my husband nor I are taller than 5'10", so I'd rather have the hood mounted a little higher to clear our heads:)

For quietness, is it worth going with the roof mounted remote blower and an in line silencer with either hood?

What are your thoughts on a wall mounted remote blower? Is this configuration significantly louder? Is there a way to use an inline silencer with that configuration or will the duct run be to short to make it a worthwhile accessory?

Any comments or thoughts are greatly appreciated.

Quietest is a large blower run at low speed at a distance with a silencer between it and the hood. The VaH blower(s) are at your ear without even any baffles blocking their blade tips turbulence noise. It may be obvious that one can assemble a collection of hood elements that uses non-VaH equipment and come up with something louder than a comparable VaH. But it is not too difficult in many configurations to be quieter.

A residential down-roof blower such as Wolf, Broan, and Abbaka sell should last many years. I've been on my roof many times and while I have never disassembled my Wolf blower, or for that matter my many years older NuTone blower, repair would not be too hazardous for the wary up to slopes of 25 degrees, I would estimate. Alternatively, a more commercial up-blast blower could be mounted on a suitable pedestal. These could be selected to run relatively slowly and still pull 1000 or as much as you want CFM with pressure losses. What repairmen will or won't do is not something I can comment on. Another alternative given an adequate attic is an in-line blower such as Fantech sells.

Now, when throwing out an efficiency demand per your first paragraph, you will have to consider that commercial hoods are as efficient as possible due to the high cost of kitchen ventilation in restaurants and other commercial kitchens. If you don't mind the look and volume impacts of a commercial hood, then an increment of higher efficiency is possible. (This is due to the ramifications of having a lot of capture volume (intake reservoir) to average out plumes across the baffle space allowing lower flow rates in many circumstances.) However, residential kitchen hoods are not normally run at full power for hours and are not usually a driver of one's electricity bill.

https://www.houzz.com/discussions/5161173/hood-faq#n=72

https://www.houzz.com/discussions/5745986/commercial-range-hood-install#n=69