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mycelial.groove
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Registered: 04/28/10
Posts: 54
Loc: West Virginia
Last seen: 4 years, 2 months
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Inlines vs. blowers
#17725558 - 02/01/13 09:18 AM (11 years, 1 month ago) |
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After spending countless hours reading through thread after thread about laminar flow hood techs, I'm still uncertain whether to go with a squirrel blower or an inline centrifugal fan. YES, tons of people say that blowers are the way to go and that inlines don't work. I believe everyone when they say that blowers work great, but are the suggestions that inline centrifugal fans don't work just speculation or first hand knowledge. I ask this because there are a fair number of first person accounts saying that their inline fan purchase has worked fine for years with zero or very nearly zero contamination.
Squirrel blowers seem harder to hook up, more cumbersome, more electrically demanding, and potentially more expensive.
The inlines often times come with a rheostat for power adjustment built into them, are already prepared for connection to an electrical outlet, are supposedly quiter, use less electricty, and are pretty damn cheap comparitively. One argument that I've heard against inlines is that they don't actually produce static pressure. The can fans say that they handle medium to high levels of static pressure (Can Fan Fact Sheet), but do they create static pressure. I just purchased a 24"x30"x5 7/8's 99.99 hepa. I plan on buying the can fan 10# which produces 535 cfm at 1.25" static pressure. It's a little more than necessary, but the 10# comes with rheostat I believe.
I would love to see responses from people that have used both and get their perspective on which is the way to go. Also, I'd love people with inline fan driven laminar flow hoods to chime in whether they have been effective or not. I very much doubt this will put an end to this debate, but I'd sure like to try.
MG
-------------------- ~So Neglect Becomes Our Ally
Edited by mycelial.groove (02/01/13 09:22 AM)
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RogerRabbit
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The air leaves a squirrel cage blower traveling in one direction. The air leaves a centrifugal fan rapidly swirling. If your intention is to cool sealed grow room lights, the centrifugal fan will scrub more heat off the lamps. If you want to ensure laminar flow, use a squirrel cage blower. RR
-------------------- Download Let's Grow Mushrooms semper in excretia sumus solim profundum variat "I've never had a failed experiment. I've only discovered 10,000 methods which do not work." Thomas Edison
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mycelial.groove
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Quote:
RogerRabbit said: The air leaves a squirrel cage blower traveling in one direction. The air leaves a centrifugal fan rapidly swirling. If your intention is to cool sealed grow room lights, the centrifugal fan will scrub more heat off the lamps. If you want to ensure laminar flow, use a squirrel cage blower. RR
I'm no physicist, but it seems that if the centrifugal fan is installed to blow directly into the plenum with no other way for air to escape that plenum besides pushing through the HEPA filter, that should build the static pressure needed to generate laminar flow. RR, just for the record, have you ever owned or used a hood powered by a inline fan?
Thanks for the advice.
MG
-------------------- ~So Neglect Becomes Our Ally
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RogerRabbit
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Quote:
RR, just for the record, have you ever owned or used a hood powered by a inline fan?
No. I have several can-fans to cool lights for a different operation so I'm used to working with them. After passing through several feet of duct, the air is still twirling.
If that swirling air is beating against the back of the flowhood filter, it seems that it would be hard to hold a steady pressure in that area. The idea of static pressure is to hold an even pressure across the entire back surface of the filter, which helps to ensure laminar flow out the front. With turbulent air on the back side of the filter, you're counting on the resistance of the filter to buffer the oscillations. RR
-------------------- Download Let's Grow Mushrooms semper in excretia sumus solim profundum variat "I've never had a failed experiment. I've only discovered 10,000 methods which do not work." Thomas Edison
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Darkman
Farmer
Registered: 04/16/11
Posts: 225
Loc: Africa
Last seen: 7 years, 5 months
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I built a vertical clean room hood in November. I used a 6" Inline blower from Tjernlund with a 15" HEPA.
Have done 1000 hip flask G2G with 0 contam.
I am really really happy with it (thanks to Sparkle for the design).
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hostyle
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Registered: 03/02/13
Posts: 60
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Quote:
mycelial.groove said: The can fans say that they handle medium to high levels of static pressure (Can Fan Fact Sheet), but do they create static pressure.
I wonder what the actual flow rate is at 1"...
Inline fan's can be used but they are usually only good (and cost effective)from 100 to 500cfm @ 1" S.P.. Difficult to find inline fan's are at 550+cfm @ 1" S.P.
Keep in mind inline fan's are used "inline" usually in ducting to move air without much resistance. Squirrel cage blowers are used in furnaces/exhaust where resistance is encountered at filters/louvre shutters etc, because of this they are usually rated for S.P.
Hope this helps.
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forrest
Registered: 11/16/12
Posts: 1,011
Loc: The Netherlands
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Re: Inlines vs. blowers [Re: hostyle]
#17932319 - 03/10/13 03:36 AM (11 years, 21 days ago) |
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this company: standardhepafilter.com specialized in flowhoods,and only uses centrifugal fans.
I'm in doubt because of all the speculation that centrifugal fans would be less good, wether i would go for the combo of fan plus filter from them, or only buy the filter and search for a squirrelcagefan myself.
so i'm pretty interested in teh actual difference myself.
Darkman, do you have a topic on how you contructed your flowhood with the inline? did you make adaptions to lower noise?
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Darkman
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Re: Inlines vs. blowers [Re: forrest]
#17937519 - 03/11/13 06:54 AM (11 years, 20 days ago) |
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Quote:
forrest said: this company: standardhepafilter.com specialized in flowhoods,and only uses centrifugal fans.
I'm in doubt because of all the speculation that centrifugal fans would be less good, wether i would go for the combo of fan plus filter from them, or only buy the filter and search for a squirrelcagefan myself.
so i'm pretty interested in teh actual difference myself.
Darkman, do you have a topic on how you contructed your flowhood with the inline? did you make adaptions to lower noise?
Here is a link http://www.fungifun.org/English/Flowhood
I use a 6" Tjernlund inline blower but that's because I built a vertical hood and my filter is only 15" by 15".
I don't find it noisy at all, it's actually soothing! But my fan is out in the open, i.e I didn't box it which would have amplified the sound.
The steps to building a vertical hood are;- 1. Build a horizontal laminar flowhood (without the hood) 2. Turn it on it's head on top of the built vertical "hood"/work-area.
When I had completed step 1 I checked for laminar flow using a lighter and incense stick and both showed true laminar flow, only then did I proceed to step 2.
Tjernlund metal body inline fans rock.
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tombosley8
Full on... Bossley Baggins
Registered: 10/14/13
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Re: Inlines vs. blowers [Re: Darkman]
#19829449 - 04/11/14 05:34 PM (9 years, 11 months ago) |
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so anyone else's input on the functionality of inline fans in a flow hood...? and why is it that this inline is so much more powerful for the cost as the SC blowers http://www.canfilters.com/max_fan_8_12.html (referring to the 12" model)??? I'm going to go ahead and order it if i get no replies by tonight... please if you advise against it let me know so my choice is between this http://www.ebay.com/itm/3-4-hp-1100-RPM-115V-Furnace-Blower-with-Housing-Assembly-Motor-1XJY2-/151027515132?pt=LH_DefaultDomain_0&hash=item2329f0fefc http://www.electricmotorwarehouse.com/PDF/1XJX7_spec.pdf and the inline i mentioned. I guess the SC blower is good enough for all my needs though i'm thinking that the can fan is good enough if i ever upgrade to a 3'x4' filter.... Opinions????
Edited by tombosley8 (04/11/14 07:05 PM)
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t3chnobily
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Registered: 02/04/12
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Re: Inlines vs. blowers [Re: tombosley8]
#19830280 - 04/11/14 08:59 PM (9 years, 11 months ago) |
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I have a 1/2hp 20" blower salvaged from a HVAC system that is more than powerful enough to push a 2' x 4' x 12" hood. Had to stack multiple prefilters to reduce flow. Sure your not way over sized?
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tombosley8
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Re: Inlines vs. blowers [Re: t3chnobily]
#19830376 - 04/11/14 09:23 PM (9 years, 11 months ago) |
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3'x4' would require 1200 cfm at 1.2" SP plus 10%-20% for uncounted for resistance so i don't think it's too much... 1200 plus 20% is 1440 so the blower is just under at 1399.
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t3chnobily
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Re: Inlines vs. blowers [Re: tombosley8]
#19831569 - 04/12/14 06:40 AM (9 years, 11 months ago) |
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What is the purpose of a 3' tall filter?
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tombosley8
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Re: Inlines vs. blowers [Re: t3chnobily]
#19831911 - 04/12/14 09:12 AM (9 years, 11 months ago) |
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very fast bag to bag transfers Even with a two foot filter my bags often go above the filter just slightly potentially letting contams bounce off the bag from above and pulling dirty air down with it. for not much more ($) it can be done so seems a good choice for me and why not more clean air it could only make it safer
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drake89
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Registered: 06/26/11
Posts: 4,168
Loc: TN
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Re: Inlines vs. blowers [Re: tombosley8]
#19832563 - 04/12/14 12:30 PM (9 years, 11 months ago) |
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Quote:
tombosley8 said: very fast bag to bag transfers Even with a two foot filter my bags often go above the filter just slightly potentially letting contams bounce off the bag from above and pulling dirty air down with it. for not much more ($) it can be done so seems a good choice for me and why not more clean air it could only make it safer
you can see a picture of our massive hepa on facebook. it's basically just insurance against our less than spotless lab. we'll be following clean room procedures more closely when we move out of this nasty warehouse.
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drake89
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Registered: 06/26/11
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Re: Inlines vs. blowers [Re: drake89]
#19832566 - 04/12/14 12:31 PM (9 years, 11 months ago) |
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you might like to know that you won't get a single seamless HEPA when it's that big, too.
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tombosley8
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Re: Inlines vs. blowers [Re: drake89]
#19833985 - 04/12/14 05:37 PM (9 years, 11 months ago) |
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Edited by tombosley8 (04/12/14 06:48 PM)
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t3chnobily
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Re: Inlines vs. blowers [Re: tombosley8] 1
#19834494 - 04/12/14 07:43 PM (9 years, 11 months ago) |
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Better off just boxing it in IMO. Whatever floats your boat
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drake89
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Re: Inlines vs. blowers [Re: tombosley8]
#19837115 - 04/13/14 11:03 AM (9 years, 11 months ago) |
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Quote:
tombosley8 said: nice build is that 4 18"x24" filters? isn't this a seamless one http://hepa.airflotek.com/item/hepa-filters-2/ultrastar-standard-capacity-wood-frame-filter-2/item-1111? and here's some http://www.hepa.com/library/hepa_lit.pdf
i'm not really sure how big they are. the outer frame is 3x4 so the inner panels are probably a couple inches smaller since there is an inner frame. I'm sure you can find a single panel that's 3x4, especially if you get a metal frame. I just went with the cheapest one I could find.
Tech- that's a nice build!
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lipa
Registered: 07/24/07
Posts: 2,684
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Re: Inlines vs. blowers [Re: forrest]
#19839864 - 04/13/14 08:21 PM (9 years, 11 months ago) |
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Quote:
forrest said: this company: standardhepafilter.com specialized in flowhoods,and only uses centrifugal fans.
I'm in doubt because of all the speculation that centrifugal fans would be less good, wether i would go for the combo of fan plus filter from them, or only buy the filter and search for a squirrelcagefan myself.
so i'm pretty interested in teh actual difference myself.
Darkman, do you have a topic on how you contructed your flowhood with the inline? did you make adaptions to lower noise?
These work good too. I would never use an inline fan for a hood but these will work. Here is a Flanders Corp ceiling unit I converted for fresh air into my Culture Lab. New they are a rip off but you can find used ones seriously cheap on ebay. They are fully stainless even the motor parts and have a built in prefilter.
You can use these to make a laminar flow hood. I've seen them as low as 100.00$. All you need is a sheet of plywood and a filter.
Lipa
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forrest
Registered: 11/16/12
Posts: 1,011
Loc: The Netherlands
Last seen: 4 years, 8 months
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Re: Inlines vs. blowers [Re: lipa]
#19840920 - 04/13/14 11:43 PM (9 years, 11 months ago) |
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i used the one from standardhepafilter after all and am quite happy with it. i put 4 prefilters on to slow it down to the right blowspeed.
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tombosley8
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Re: Inlines vs. blowers [Re: forrest]
#19845558 - 04/14/14 07:46 PM (9 years, 11 months ago) |
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ended up going squirrel and got this one http://www.ebay.com/itm/151027515132 that will run my 2'x2' i have currently and when i upgrade it can run a 3'x4' filter ... reasonable price too.
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