Anyone know a thing or two about Kitchen Duct

[mobiledynamics]

Anyone know a thing or two about Kitchen Exchaust Duct

Remote Blower, Straight and smooth, etc, etc

Sorta in a weird pickle for this new build. 1200CFM blower and the duct run is a bit against -best practice-. I did a test fit and the noise is acceptable.....but not ideal. I'm working on constraints of the layout

So basically
Hood Blower
Right off the hood blower is a 10" 90 Degree Elbow to make it go right
Then two 45"s to make a turn vertical
Then up to the roof

Yeah, I know I should have like 2 feet from the blower off that's 1st elbow. It is what is is. The noise levels is ~acceptable~.

Only issue aside from the run itself is some direct backpressure coming off the 90. It is what it is though...

I'm sure the air will be moving, albit not ideal. The oil particulates the filters don't catch might be a ~sticking point~ though right ?

 

[mobiledynamics]

Looking at just the test fit

90 degree-45-45 going Vert
Between the 90degree and right off that the 45, man, not sure is this is a terrible grease trap in the making

 

[yeldogt]

It has been my experience that the remote fans do collect more grease in the exhaust pipe. I only have one modern set up that way .. it was common for larger stoves years ago because consumer models did not exist in the higher CFM's

While the remote blowers are quieter -- they are not quiet on high.

And Yes -- all the blowers benefit from having a proper smooth transition.

My recommendation would be to find a local HVAC metal shop and have them make the proper transition.

I thought you had a chimney set up ?

 

[mobiledynamics]

IMO, the baffle filters - are designed/bent/shaped to capture most of the oil particulates. The stuff that get's bypasses...is where the duct install becomes more crucial.
The noise from remote blowers is just a different type of noise - the noise generated from the air passing through the baffles. I prefer remote/inline as far down the run as possible if given the option over internal blowers.

For this particular redo, my only options is internal with the duct run as stated. 90 elbow, then double stacked 45 to go vert. Not ideal but just building around construction constraints. Hvac shop ain't going to be able help regarding the run.

Eh, I suppose as long as I walk into this knowing all this and knowing I've thought it through...ya know. Just wanna those.

 

[yeldogt]

not that it matters .. but in the first post you say "remote blower" and #4 you say "internal""

The pressure point matters -- that's why the need for smooth transition after the blower .. the point of highest pressure.

the motor and fans pick up a lot of junk after the baffles -- it's a compromise/ I took a good look at one of mine as we were cleaning up prior to Christmas .. getting sort of funky. Was thinking maybe a trip to my independent and his parts washer this summer.

 

[mobiledynamics]

remote blower and inline blower - same to me, meaning away from the primary room and much further down the line of the run where noise is not a issue.

I'm pretty religious on cleaning when it comes down to this stuff. Baffles are cleaned regularly. In the primary M-F home, baffles at least once a week. Maybe every 10 day at most. The squirrel wheels come out for a cleaning every once in a blue moon. And yes, the choke point which I am hemming and hawing at is the piss poor choice of having to put a 90 right off the internal blowers.

 

[yeldogt]

remote blower and inline blower - same to me, meaning away from the primary room and much further down the line of the run where noise is not a issue.

I'm pretty religious on cleaning when it comes down to this stuff. Baffles are cleaned regularly. In the primary M-F home, baffles at least once a week. Maybe every 10 day at most. The squirrel wheels come out for a cleaning every once in a blue moon. And yes, the choke point which I am hemming and hawing at is the piss poor choice of having to put a 90 right off the internal blowers.

Sorry -- it's still not clear. Looking at the other thread -- I guess you have the inline. #4 said internal ... maybe spellcheck changed. But - you say "internal" again in your last post.

I toss mine in the dishwasher at most a couple times a month. they don't trap grease like the SS mesh -- but, they don't allow enough air.

I use a lot of internal blowers -- they like a minimum 2' of straight pipe on each end .. but it's most important after. Same with the internal setups -- the 90 degree is a very wide smooth trunk ... and it's still not as good as having the straight pipe.

The stove in my current project is huge -- so, we spent a lot of time working on the hood and piping.

Sound like you are going to have to live with it or make some more involved changes

 

[mobiledynamics]

Yes, for this current app, we're talking internal blowers in the hood.

Sorry. I'm not being clear. I'm just saying if given the right construction conditions that don't dictate the piss poor duct routing like we have now, I would prefer inline or remote blower anyday versus the internal blowers.

BTW, what's your duct run/stove. If given new construction or the duct design allows, I always employ a silencer in the mix as well. Fantech LD series