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realrasta
man in my closet

Registered: 01/19/03
Posts: 171
Last seen: 17 years, 4 months
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flow hood test needed
#4681553 - 09/19/05 11:19 AM (18 years, 4 months ago) |
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so i built a box with a 13,000 cfm squirrel cage blower. and instead of a hepa i made one (well sorta) using the furnace filters. 8 to be exact and i bought more higher end than lower end. so its all sealed and the air flow seems really light. so my question in how can i test to see if there is enough flow. and i know there probably isn't a sure test ( although i hope there is) but can u tell me something like ....a good flow will blow a piece of paper at a 45 degree angle? please help don't wanna waste my stuff
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backupwards
peon

Registered: 04/02/05
Posts: 3,022
Loc: somewhere else
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Re: flow hood test needed [Re: realrasta]
#4681761 - 09/19/05 12:09 PM (18 years, 4 months ago) |
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well even using high end filters they won't act as a hepa unless they are true hepa filters. 13,000 cfm fan, damn boy that should blow you away.
take a candle, light it, turn the flowhood on. if the candle blows out you have to much flow. if the candle bends over say like 90 degrees and doesn't go out then you are good. if it kinda flickers then you don't have enough flow. you can always try and get a flow meter too.
how small of a micron does your best filter filter?
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realrasta
man in my closet

Registered: 01/19/03
Posts: 171
Last seen: 17 years, 4 months
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Re: flow hood test needed [Re: backupwards]
#4682075 - 09/19/05 01:25 PM (18 years, 4 months ago) |
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my last 3 r 0.3 microns. is that bad
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Pinx
Stranger
Registered: 06/20/05
Posts: 56
Last seen: 16 years, 7 months
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Re: flow hood test needed [Re: realrasta]
#4682291 - 09/19/05 02:10 PM (18 years, 4 months ago) |
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how about puting several agar plates(mea, pda...) in your hood and open them for 15 to 20 minutes(or longer if you wish) and then incubate them for 48 hours... if it works most of the plates should stay as they are...
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RogerRabbit
Bans for Pleasure


Registered: 03/26/03
Posts: 42,214
Loc: Seattle
Last seen: 11 months, 2 days
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Re: flow hood test needed [Re: Pinx]
#4682342 - 09/19/05 02:26 PM (18 years, 4 months ago) |
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Furnace filters, regardless of micron size will not deliver laminar flow. Besides, it's a waste of filters to stack more than one furnace filter on another. For example, a chain link fence isn't going to stop a mosquito from flying through it. Why would two chain link fences or three, or even ten chain link fences stop that same mosquito? That's why 8 or 80 furnace filters isn't going to stop that trich spore. Also, a 13,000 cfm blower would require an 18 wheel tractor trailer to deliver it to your warehouse. That's hardly flow hood material. Most likely it's 1300 cfm, which is about right for 48" X 60" flowhood.
8 furnace filters should have cost as much as a proper laminar flow hepa filter from fungi.com which is about the most expensive place to order one from. 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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Pinx
Stranger
Registered: 06/20/05
Posts: 56
Last seen: 16 years, 7 months
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Re: flow hood test needed [Re: RogerRabbit]
#4682424 - 09/19/05 02:46 PM (18 years, 4 months ago) |
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btw 0.3 microns is as big as a hepa filter, at least per definition
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RogerRabbit
Bans for Pleasure


Registered: 03/26/03
Posts: 42,214
Loc: Seattle
Last seen: 11 months, 2 days
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Re: flow hood test needed [Re: Pinx]
#4682496 - 09/19/05 03:05 PM (18 years, 4 months ago) |
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Yea, I saw that, but the difference is in laminar flow, and also what percentage of contaminants will be filtered out to .3 microns. There's a huge difference in the price of filters that will filter 99% down to .3 and those that will filter 99.9% of particles down to .3 microns. If the flow coming out the filter is turbulent, it will draw in contaminants from the air surrounding the work area. Also, what kind of furnace filter can filter down to .3 microns?
-------------------- 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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Pinx
Stranger
Registered: 06/20/05
Posts: 56
Last seen: 16 years, 7 months
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Re: flow hood test needed [Re: RogerRabbit]
#4682529 - 09/19/05 03:13 PM (18 years, 4 months ago) |
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i agree on the percentegaes hepa is 99.97% afaik
but as soon as the laminar flow hits anything within the hood there will be a turbulence so im not convinced that this will make such a difference(in a homemade laminar flow..)
i think a homemade flow hood is just a play with numbers when you filter out 90% of the paricles you have won another 24 hour for the desired "infection" to take place... but this is just an assumption
greets
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mycofile
Pooh-Bah


Registered: 01/18/99
Posts: 2,336
Loc: Uranus
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Re: flow hood test needed [Re: Pinx]
#4684260 - 09/19/05 09:50 PM (18 years, 4 months ago) |
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laminar flow, by definition means that the turbulence won't pull in surrounding air, be it in a home made hood or a professional lab.
And no, homemade flow hoods aren't a crap shoot. I can open anything I want in front of my hood, close it back up, and it will never contaminate. Not in 24 hours, not in 24 days.
Sterile is sterile, laminar is laminar, hepa is hepa. Matters not who makes it or where it's used. This furnace filter based hood isn't hepa, and it isn't laminar. That means the air in front of it isn't sterile.
Roger is right on...
-------------------- "From a certain point of view" -Jedi Master Obi Wan Kenobi PM me with any cultivation questions. I just looked at my profile and realized I had a website at one point in time on geocities, it's not there anymore and I have no idea what I had on it. Anybody remember my website from several years aga? PM if so please.
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