An indoors charbroiler, eh? According to the Greenheck Kitchen Ventilation Guide, the desired air velocity into the hood aperture for charbroilers is 150 ft/min, higher than the 90 ft/min I usually suggest for good containment in residential cooking to handle griddles, woks, etc. Even if the hood is only 3.5 x 2 ft in aperture size (7 sq. ft.), this calls for 1130 CFM, which in turn calls for a blower with a fan curve that can supply that flow rate at the pressure losses incurred by the baffles, ducting, and MUA path. The blower's zero static pressure rated flow rate to meet this requirement can be as high as 1700 CFM. If the ducting is short and the MUA is powered to compensate for its pressure loss, then maybe a 1200 to 1500 CFM rated blower will suffice. Wolf, Broan, and Abbaka have external blowers in this size; Fantech can provide equivalent in-line blowers.

However, you are in the zone where just the MUA system alone could eat up most of your budget. Residential exhaust ventilation parts can be found in Wolf's design
guide, while residential powered MUA systems may be found at Fantech's
web site.

You are in the zone where the higher flow rate will significantly increase baffle noise, even if all other noise sources were suppressed.

For best competitive pricing in this case, I would guess that a commercial setup would be worth investigating. Restaurant style MUA intakes and upblast blower exhaust systems may provide some noise benefit. The commercial hood assemblies are not so pretty but potentially lower in price. (You wouldn't need the extinguisher parts, I hope.) Frankly, I doubt that this charbroiler requirement can be addressed by only $3k unless you live where there is no need for a dedicated (and heated) MUA system (Pago Pago perhaps).

You can gain significant understanding of the issues by downloading the guide at this URL and reading at least the first 20 or so pages.

http://www.greenheck.com/media/pdf/otherinfo/KVSApplDesign_catalog.pdf

kas

Thanks for all the advice!

Just to be clear, this is the range: http://www.subzero-wolf.com/wolf/ranges/gas-range/36-inch-gas-range-4-burners-infrared-charbroiler

Wolf specifies a 900 cfm hood for this particular model. We have a few friends who have the same model with 900-1200 cfm hoods and they seem happy with the setup.

Fortunately I'm in a temperate climate (northern California), and have an 1892 house that leaks a ton of air and from discussing with the local vendors, MUA won't be required.

I was thinking of a Vent-a-hood wall unit with 900-1200 cfm. The friends who have them are happy and the noise level is ok. Do you think moving the blower outside would help with the noise much? Our kitchen is directly under a vaulted ceiling, so the external blower would only be ~3' away from the hood, with no crawl space in between. I imagine it would still help, but I'm not sure it's worth the added cost.

I don't have a charbroiler, and frankly, it is unclear to me just what the differences are in smoke and rising plume velocity between this range and a commercial char broiler, other than size of the surface area. Hence, it may be better for scaling of needed flow rate to depend on your friends' experience, although it would be best to get them to demonstrate for you that the smoke is adequately captured and contained within the context of your definition of adequate.

Three feet is not much distance, and too small for a Fantech silencer for the duct size. Hence an exterior blower is better only if one of its other properties makes it advantageous in a particular case.

A leaky house is leaky when the pressure inside is lower than outside. So the actual pressure loss could still degrade the flow rate achieved. (It could also back-draft combustion appliances, so that is another issue to consider.) Pressure loss will have a greater effect on the Ventahood models I've looked into, but if you have a demonstration of adequacy (for equivalent MUA), then that effect will be accounted for.

With Ventahood, you don't get baffles; the blower squirrel cage is used to centrifugally extract the grease (well some of it depending on particle size) and deposit it on the blower assembly walls. I think most believe that washing baffle assemblies in a dishwasher and wiping down the exposed internal hood surfaces are less overall effort than disassembling and cleaning a VaH, but again I don't have one (I avoid magical devices) so I cannot state that as my experience. I think the left-hand hood image half-way down the Wolf web page you provided a link to is better looking, but your opinion on that matters and mine doesn't.

kas

Thanks so much for all the input! Sounds like the external blower might not be worth the money in this scenario.

Regarding the make up air - does an open window do a decent job of not restricting the hood, assuming the city doesn't require some sort of make up air? We have windows on either side of the range, and we pretty much have some window open about 300 days a year here... No AC and we only run the heat for a few weeks every year.

Do you have any recommended range hood brands? There's such a huge selection... I've been looking at Broan, Zephyr, Vent a hood, Best, and a few more.

I was curious which hood Kaseki was talking about that is on your link. It's a Wolf brand, and it does look good. I have a feeling because it has the Wolf badge that it is $$$. I think I read that Wolf contracts with Best by Broan to build Wolf hoods. That doesn't mean they'll be the same, but you should give Best by Broan a look.