1500 CFM blower delayed-wait or install 900 CFM blower now?

last year

Hi All,

I ordered a Wolf 22" proliner and 1500 CFM remote blower 5 weeks ago. It will be installed with a silencer and make-up air by a licensed HVAC technician.

Just now, I received an email from the appliance store that the blower is backordered until October. I was expecting to receive it last week and had planned my project timeline so that my kitchen would be fully completed and functioning at the end of August. They can offer me the 900 CRM remote blower now if I don't want to wait.

I prefer the higher CFM but this means I'll be cooking outdoors for 2-3 more months into fall (chilly/damp in my area) if I go this route. I'd appreciate some thoughts on whether the 900 vs 1500 cfm would make a significant difference in air quality and noise to justify the wait. Thank you!

Featured Answer

kaseki

last year

The OP hasn't specified the hood width, thereby making it difficult to determine actual and rated flow requirements. However, if we are to bypass this minor detail, the general physical features of the Wolf roof blowers (previously sourced from Broan/NuTone, who seem to be discontinuing these models) may be found in Abbaka Hy-Ex roof blowers (see specs below). These are now sold by BlueStar and distributed by various sources: https://dvorsons.com/Abbaka/Abbaka.html

The OP will have to get Wolf to confirm that the hood has a blower control compatible with induction motors, and get Bluestar to confirm that the Abbaka blowers are suitable for simple phase control, 2-wire power (not the multi-winding schemes Thermador and others have used). Otherwise, it is possible that some adaptation would be needed.

Note that the Broan/NuTone (Wolf) 1500 CFM blower fan curve shows 1000 CFM at one inch w.g. pressure loss, so it is more powerful than the Hy-Ex 1.4. This is why an analysis by the HVAC people to determine actual flow rate with MUA may be needed. You want at least 90 ft/min at the entrance aperture of the hood canopy for good containment of the captured cooking plume(s).

Another alternative would be a roof cap with an in-line blower. Fantech, among others, have a plethora of in-line blower models.

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Comments (8)

fsq4cw
last year
Have you tried sourcing this part elsewhere?

Can you post a 'sticker' image of the blower part/serial number, manufacturer etc.?

SR
Clyde Kalvin
last year
For me I would wait and get the 1500 cfm. We have 1200cfm and I would not want any lower for some of the things we cook.

What appliance is this going to be venting and what kind of cooking do you do?

You may have to cook outside for a few extra months but will be living with the vent for years.
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Charles Ross Homes
last year
The specified blower is on back order and out of stock at your local dealer. Have you checked other dealers to see if one has it in stock? A couple of minutes of internet searching and a few phone calls might make your problem go away.
HU-494288216
Original Author
last year
last modified: last year
@kaseki Thank you very much for your time. The hood width is 42" wide and 22" deep for a 36 Bosch 800 induction cooktop. Here is the hood: https://www.subzero-wolf.com/wolf/range-hood/42-inch-pro-hood-liner-22-inch-depth

The blower is Wolf 804701.

https://www.subzero-wolf.com/store/installation/wolf/ventilation/1500-cfm-remote-blower

Is there a Broan-Nutone 1500 external blower that would well as an alternative?

https://broan-nutone.com/en-us/accessory/336

I have asked other local sellers of the Wolf 804701 and it's the same shipping delay. The local stores all come from the same distributor. It appears to be available at some online stores but I don't know how reputable these stores are and I prefer not to deal with shipping/return issues.
kaseki
last year
As far as I know, the Wolf 804701 and Broan/NuTone 336 are the same blower, although the fan curve published by Broan differs very slightly from that sent to me by Wolf years ago. What I don't know, however, is whether Wolf imposes additional requirements on Broan to make a 336 into a 804701; for example, replacing a galvanized steel part with aluminum. What else I don't know, for example, is whether Wolf has taken over production.

AJ Madison claims (at the moment on their website) that they have the Wolf 804701 in stock. Since one has to call for price, one can determine whether sales will confirm that. https://www.ajmadison.com/cgi-bin/ajmadison/804701.html?srsltid=AfmBOorNT0RkwQAY1vWGe-a4vxdR9T96roqU-Io7rzwpkeD5l7Eewn. SubZero/Wolf answers the phone. You could call to confirm that AJM is an authorized seller.

On the flow rate requirement, a 42 x 22 hood has a nominal entry aperture of 6.4 sq. ft. The desired actual air flow rate would be 90 ft/min times this or 580 CFM. Rated CFM should be 1.5X this or a nominal 900 CFM. I don't think you actually need 1500 CFM, unless you want to further minimize noise by only running the blower at partial speed. Note that where Code Enforcement is particular, you would need a 1500 CFM capable MUA system (passive or active depending on combustion appliances), even though the actual flow rate would be lower.
HU-494288216
Original Author
last year
Thank you very much, @kaseki! I've read dozens of your very thorough responses to other queries and I just want to extend my heartfelt gratitude for your time and patience as you answer (and re-answer) questions.

I tried sourcing the Broan Nu-Tone 336 only to discover that it has been discontinued with limited availability. I'll wait for the Wolf 1500 CFM. I have incredibly (and painfully) sensitive ears so I plan to run it at partial speed.
kaseki
last year
You are welcome. One other option if needed: Get an upblast blower to use either on a roof pedestal or horizontally mounted to a wall. Size so that the fan rpm is low at full voltage for minimal noise. This may be done with appropriate sheave ratios depending on blower design. By low I mean size to generate the needed flow rate at the anticipated system pressure loss, but at less than that particular size of blower could produce. One advantage is that Code Enforcement will not demand a 1500 CFM MUA solution if you can document a lower flow specific design.

John Liu's upblast blower mounted on a wall: (Ref: https://www.houzz.com/discussions/6498197/hood-noise-internal-vs-remote-blower-on-an-external-wall-maybe-vah#n=29)

In image below, note guts of cut-away; fan drive is indirect allowing speed selection at full power by 'gearing' between shafts. You might need professional support from a distributor to determine what to order.