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roarkell
The Roar Master!



Registered: 08/29/19
Posts: 2,223
Loc: Southern WI
Last seen: 6 months, 21 days
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Flowhood centrifugal fan question.
#26699151 - 05/27/20 10:08 AM (3 years, 7 months ago) |
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I ordered a 24x24x6 HEPA filter and am starting to design my box. In the midst of this I'm also repairing my basement stairs and in that process came across this fan.

I ran through all 3 posts regarding centrifugal fans in the search function so I figured I'd post it up here. Will this fan even work for a flowhood? Would it work if I built in baffles or put soundproofing/foam on the inside of the plenum?
Also, money isnt a big deal for me so if I have to buy a Dayton I will... just wanted to see if i could re-purpose this.
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Strainsfordaze


Registered: 05/10/18
Posts: 669
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Re: Flowhood centrifugal fan question. [Re: roarkell]
#26699194 - 05/27/20 10:34 AM (3 years, 7 months ago) |
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You'd be better off with a squirrel cage blower.
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SFS96
AstroMan



Registered: 12/09/18
Posts: 2,144
Loc: Valleys Of Neptune
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At 440cfm with no resistance it’s probably not going to work.
-------------------- How I make and preserve tea
Consuming consumes a man That was never a purpose of life To only crave for material joys Is believing the lie - Mellow Mood
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natedawgnow
Rocky mountain hood rat



Registered: 02/09/15
Posts: 8,939
Loc: ation
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Re: Flowhood centrifugal fan question. [Re: SFS96]
#26699236 - 05/27/20 11:05 AM (3 years, 7 months ago) |
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Lots of confusion about fans on this board.
That is not a centrifugal fan. That is an in line vortex fan, which suck against resistance.
A centrifugal fan is a squirrel cage blower/furnace blower and that's what you need.
For a hood your size, you need a fan that can push 400cfm at 1.2" sp. The fan pictured only does 400cfm at open air so no way will it work.
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micelio
Song of Silence


Registered: 04/22/14
Posts: 1,547
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Re: Flowhood centrifugal fan question. [Re: roarkell]
#26699250 - 05/27/20 11:18 AM (3 years, 7 months ago) |
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This Is the blower you need for laminar flow..
https://www.grainger.com/product/DAYTON-OEM-Blower-1TDU2
Check ebay for a better price..
This Is the blower Fungi Perfecti uses on their 24"x24"x6"..
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roarkell
The Roar Master!



Registered: 08/29/19
Posts: 2,223
Loc: Southern WI
Last seen: 6 months, 21 days
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Re: Flowhood centrifugal fan question. [Re: micelio]
#26699282 - 05/27/20 11:46 AM (3 years, 7 months ago) |
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Ah... I didn't think about the s.p... thanks guys! I still have plenty of time before the filter even gets here so I'll find the proper fan soon.
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sh4d0ws
LSx


Registered: 02/26/08
Posts: 12,086
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Re: Flowhood centrifugal fan question. [Re: roarkell]
#26699357 - 05/27/20 12:40 PM (3 years, 7 months ago) |
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There are inline vortex fans that push air at a sufficient CFM to provide laminar flow but you'll definitely need to check the specs.
I really recommend contacting some hvac companies and asking if you could buy any used blowers they have lying around, because a brand new blower is gonna cost you a fortune and a lot of them have delivery dates in August and past that, seen that posted a couple times here lately.
My flowhood has an inline fan but I was able to get a chart from the seller to find out how the air flow was affected with resistance. And was able to get the right sized fan for my specific hepa filter.
It works, been using it over 2 years.
I built it based on the design from anno at fungifun.org
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micelio
Song of Silence


Registered: 04/22/14
Posts: 1,547
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Re: Flowhood centrifugal fan question. [Re: roarkell]
#26699405 - 05/27/20 01:03 PM (3 years, 7 months ago) |
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Your fan Is for moving large volumes of air. They're noisy also.
Building your box, be sure to have a large plenum area behind your filter. I have 19.5 inches deep of plenum for laminar flow.
If you have any questions I'll be happy to guide you and then theirs allot of other knowledgeable folks that'll help you out.
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roarkell
The Roar Master!



Registered: 08/29/19
Posts: 2,223
Loc: Southern WI
Last seen: 6 months, 21 days
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Re: Flowhood centrifugal fan question. [Re: micelio]
#26699803 - 05/27/20 03:38 PM (3 years, 7 months ago) |
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So, the manufacturer website is currently down for maintenance... go figure... but itll still be a while before my filter gets here anyway. I'm gonna mock up some cardboard boxes to see what kind of enclosure I wanna go with... i really like the one c10 built in his thread here https://www.shroomery.org/forums/showflat.php/Number/24137384/fpart/6/vc/1#24137384
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Machiavelliavore
Vermiculite Hater



Registered: 12/08/14
Posts: 3,038
Loc: The Sporetorn States
Last seen: 3 months, 19 days
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Re: Flowhood centrifugal fan question. [Re: roarkell]
#26699876 - 05/27/20 04:21 PM (3 years, 7 months ago) |
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I just did a shitton of research for using such a fan with a flowhood and what kind of CFM decline I could expect at certain resistances. At 1.2" WG you can expect most 6" centrifugal fans to put out about 35-45% of their rated CFM. This is just a guess based on manufacturer data from fantech, tjelurund, and some other one
https://www.tjernlund.com//Tjernlund_M-Series_Specifications_8506014.pdf https://www.acwholesalers.com/manuals/fg_brochure.pdf https://www.rewci.com/duct-fan-inline-soler-palau.html (units have performance data for different resistances)
My flowhood is a 12x12 and I elected to go for a 300cfm 6"
For a 2'x2', you'd need an inline centrifugal blower putting out at least 800cfm optimistically to hit you're looking for. Honestly I think this fan looks to be kinda tapped out for anything over a 1'x2' filters unless you are using a hepa that is down at the .5 in wg level of resistance, which since you're running a 6" thick filter, is not likely.
--------------------
I spawned some popcorn casings and had double-overlay cause I didn't put enough hydrogen peroxide in my automated aquarium mister. I only got one mushroom so I cut off the head part where the seeds fall from and put it in a jar of LC and sprayed it all over a tin of PF cakes I made with gravel, cardboard, and bisquick in my microwave. I think it will be good cause B+ is so potent. Triggered yet? Only a square would say "a cube is a cube."
No, this does not look right...
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roarkell
The Roar Master!



Registered: 08/29/19
Posts: 2,223
Loc: Southern WI
Last seen: 6 months, 21 days
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Does anyone have any solid data on plenum depths? Where I'm planning to put this is kinda a tight spot so I was thinking of just the 1 to 1 ratio (6" filter, 6" plenum)... anyone know of any reasons I might want more?
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roarkell
The Roar Master!



Registered: 08/29/19
Posts: 2,223
Loc: Southern WI
Last seen: 6 months, 21 days
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Re: Flowhood centrifugal fan question. [Re: sh4d0ws]
#26699916 - 05/27/20 04:45 PM (3 years, 7 months ago) |
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Quote:
sh4d0ws said:
I really recommend contacting some hvac companies and asking if you could buy any used blowers they have lying around
I like this idea but I'm always worried they're gonna ask what its for... any good cover stories? Or do most people not give a shit?
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micelio
Song of Silence


Registered: 04/22/14
Posts: 1,547
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Re: Flowhood centrifugal fan question. [Re: roarkell]
#26700073 - 05/27/20 06:14 PM (3 years, 7 months ago) |
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Quote:
roarkell said: So, the manufacturer website is currently down for maintenance... go figure... but itll still be a while before my filter gets here anyway. I'm gonna mock up some cardboard boxes to see what kind of enclosure I wanna go with... i really like the one c10 built in his thread here https://www.shroomery.org/forums/showflat.php/Number/24137384/fpart/6/vc/1#24137384
To be honest with you the link you sent of a flow hood Looks cool and all but I myself would not go that route. Here's why:
That Is a work station design for factories where they can stack allot of units In one location. With the two sides and top shielding you're creating parasitic drag.
The friction of air against the surface slows down while the main air velocity stays constant. A sure way to create turbulence.
Parasitic drag is drag that acts on an object when the object is moving through a fluid. In the case of aerodynamic drag, the fluid is the atmosphere. Parasitic drag is a combination of form drag and skin friction drag.
I'm into Laminar flow.. What is the principle of laminar air flow? - Quora. Laminar flow is defined as air moving at the same speed and in the same direction with no or minimal cross over of air streams or lamina. In fluid dynamics it occurs when a fluid flows in parallel layers with no disruption between the layers.
Five years ago I built a mock up of a work station design (out of cardboard) with the sides and top. Doing the smoke test I notice a vortex that would suck the smoke all the way into the filter area. I tried for a week redesigning to no prevail. The law of physic won and I gave up. There's a trade off. Work station design (takes less floor space) Or the conventional design (more floor space but true laminar flow)
I know what people will say, I have the work station design and I don't get contaminates and It's probably true. So what I just wrote Is a me thing and how I feel about the subject.
Parasitic drag something to consider.
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Apples in Mono
Not a puppet


Registered: 09/21/17
Posts: 3,240
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Re: Flowhood centrifugal fan question. [Re: roarkell]
#26700100 - 05/27/20 06:29 PM (3 years, 7 months ago) |
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Quote:
roarkell said:
Quote:
sh4d0ws said:
I really recommend contacting some hvac companies and asking if you could buy any used blowers they have lying around
I like this idea but I'm always worried they're gonna ask what its for... any good cover stories? Or do most people not give a shit?
If they ask, tell them you're building a flowhood. They aren't illegal. It's not like they're gonna report you to the law for building a flowhood. And even if they did, they'd probably just be laughed at or told to stop making police reports about legal activity
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roarkell
The Roar Master!



Registered: 08/29/19
Posts: 2,223
Loc: Southern WI
Last seen: 6 months, 21 days
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Quote:
Apples in Mono said:
Quote:
roarkell said:
Quote:
sh4d0ws said:
I really recommend contacting some hvac companies and asking if you could buy any used blowers they have lying around
I like this idea but I'm always worried they're gonna ask what its for... any good cover stories? Or do most people not give a shit?
If they ask, tell them you're building a flowhood. They aren't illegal. It's not like they're gonna report you to the law for building a flowhood. And even if they did, they'd probably just be laughed at or told to stop making police reports about legal activity
That's fair... I just like to have something prepped that's not cult related... I actually made a freeze dryer because I had a story about it when I went to buy bulk dry ice for my closed loop... maybe I'm just being paranoid... lol
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roarkell
The Roar Master!



Registered: 08/29/19
Posts: 2,223
Loc: Southern WI
Last seen: 6 months, 21 days
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Re: Flowhood centrifugal fan question. [Re: micelio]
#26700289 - 05/27/20 07:49 PM (3 years, 7 months ago) |
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Quote:
micelio said:
Quote:
roarkell said: So, the manufacturer website is currently down for maintenance... go figure... but itll still be a while before my filter gets here anyway. I'm gonna mock up some cardboard boxes to see what kind of enclosure I wanna go with... i really like the one c10 built in his thread here https://www.shroomery.org/forums/showflat.php/Number/24137384/fpart/6/vc/1#24137384
To be honest with you the link you sent of a flow hood Looks cool and all but I myself would not go that route. Here's why:
That Is a work station design for factories where they can stack allot of units In one location. With the two sides and top shielding you're creating parasitic drag.
The friction of air against the surface slows down while the main air velocity stays constant. A sure way to create turbulence.
Parasitic drag is drag that acts on an object when the object is moving through a fluid. In the case of aerodynamic drag, the fluid is the atmosphere. Parasitic drag is a combination of form drag and skin friction drag.
I'm into Laminar flow.. What is the principle of laminar air flow? - Quora. Laminar flow is defined as air moving at the same speed and in the same direction with no or minimal cross over of air streams or lamina. In fluid dynamics it occurs when a fluid flows in parallel layers with no disruption between the layers.
Five years ago I built a mock up of a work station design (out of cardboard) with the sides and top. Doing the smoke test I notice a vortex that would suck the smoke all the way into the filter area. I tried for a week redesigning to no prevail. The law of physic won and I gave up. There's a trade off. Work station design (takes less floor space) Or the conventional design (more floor space but true laminar flow)
I know what people will say, I have the work station design and I don't get contaminates and It's probably true. So what I just wrote Is a me thing and how I feel about the subject.
Parasitic drag something to consider.
I appreciate the info dude! I too made a cardboard mock up and am already second guessing the c10 style build... the main reason being the spot I had planned to put it has limited electrical access. So in gonna need something more mobile... its 2' square already... I'm thinking of making the plenum ~10" add the 6" for the filter and then I can get a 16x24x1 pre filter. I'm thinking I'll run it with the blower on the side tho... I'll have to play around with that when I get the blower and filter in hand. But I'm 99% sure I'm not gonna put the wall/top on it, along your train of thought with the drag.
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roarkell
The Roar Master!



Registered: 08/29/19
Posts: 2,223
Loc: Southern WI
Last seen: 6 months, 21 days
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Re: Flowhood centrifugal fan question. [Re: roarkell]
#26717808 - 06/03/20 09:12 PM (3 years, 7 months ago) |
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Big shout out to all you guys for helping me out with all this... here's the final product... I haven't decided if I want to paint/stain it or not... just let it run for about 10 minutes and then did a couple open plate tests and for shits and giggles I took an old germ plate and did a few xfers... hopefully I did everything right and the plates stay clean!
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