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ozzysmygod
Late Night PC'ing Enthusiast



Registered: 11/26/08
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Building HEPA, a little help from a Trusted Cultivator required (others feel free to comment)
#12402594 - 04/16/10 08:40 AM (14 years, 9 months ago) |
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PLEASE SEE END OF THREAD
I've seen conflicting information regarding matching a Blower to a HEPA. Some sources say each foot should be blowing 100ft3/min, others say a 2ft x 2ft HEPA requires a total of 500ft3/min (instead of 400) Some people have added to the Pa of the filter to include a prefilter, other sources say this is not necessary?
So how should I calculate it?
I am using a 24" x 24" HEPA, and the stats are highlighted in red below

Could someone possibly tell me the best way to calculate it, or even better give me the answer I dont know what i will be using as a prefilter as im based in the UK. I think it will be an air conditioner filter, or a cooker hood filter.
Thanks for your help!! ,
Edited by ozzysmygod (05/06/10 06:00 PM)
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ozzysmygod
Late Night PC'ing Enthusiast



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Re: Building HEPA, a little help required. [Re: ozzysmygod]
#12408602 - 04/17/10 11:57 AM (14 years, 8 months ago) |
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Can anyone please help on this one? I have used the search feature, but the information I have found contradicts each other.
Thanks again
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mister
Nature nut



Registered: 10/04/08
Posts: 2,926
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Re: Building HEPA, a little help required. [Re: ozzysmygod]
#12408631 - 04/17/10 12:02 PM (14 years, 8 months ago) |
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I just use a 463 cfm dayton blower for my flowhood which is 12 X 24. works awesome. my flame from my alc. lamp stays lit but is blown sideways. Never had contams while using it to do agar work.
--------------------
   
   AMU Q & A thread  
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hamloaf
Q-dood ®©™√



Registered: 12/23/09
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Re: Building HEPA, a little help required. [Re: ozzysmygod]
#12408634 - 04/17/10 12:03 PM (14 years, 8 months ago) |
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Quote:
ozzysmygod said: Can anyone please help on this one? I have used the search feature, but the information I have found contradicts each other.
Thanks again
Good job on waiting 24 hours to bump your thread.  Here is the link you require. http://www.fungifun.org/English/Flowhood
...and here is how I discovered it.  http://www.shroomery.org/forums/showflat.php/Number/12157708/page/11
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ozzysmygod
Late Night PC'ing Enthusiast



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Re: Building HEPA, a little help required. [Re: hamloaf]
#12415065 - 04/18/10 01:48 PM (14 years, 8 months ago) |
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Thanks, that link still contradicts other info ive seen on these forums, and I dont know which to go with. Have you built a hood to fungifuns instructions hamloaf, and does it work
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hamloaf
Q-dood ®©™√



Registered: 12/23/09
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Re: Building HEPA, a little help required. [Re: ozzysmygod]
#12416667 - 04/18/10 06:49 PM (14 years, 8 months ago) |
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Pics soon. Forget that other information. Follow fungifuns instructions.
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ozzysmygod
Late Night PC'ing Enthusiast



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Re: Building HEPA, a little help required. [Re: hamloaf]
#12510652 - 05/05/10 01:04 PM (14 years, 8 months ago) |
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Okay, so I ordered the HEPA filter, and it should be arriving next week. Please can some one check the blower I plan to use?
BLOWER
on the left of the page, in the middle, you can see the working point, which is the air flow at 250pA same as the filter

FILTER (In Square)

Also, the filter has a rated air flow of 850m3/hr , but the blower Ive selected has an air flow of 1030m3/hr... does this not include the back pressure of the filter? (IE with 250pA of back pressure, will the blower blow around 850m3/hr ? I don't want to break it :S
I'd really appreciate it if a Trusted Cultivator or maybe even RR could comment on this, I really want to get it right.
Thanks again shroomery!
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ozzysmygod
Late Night PC'ing Enthusiast



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Re: Building HEPA, a little help required. [Re: ozzysmygod]
#12518299 - 05/06/10 06:02 PM (14 years, 8 months ago) |
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can no one help me on this? Ive waited 24 hours to bump the thread. I just want a quick answer and i'd be so grateful for the help.
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ozzysmygod
Late Night PC'ing Enthusiast



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Re: Building HEPA, a little help required. [Re: ozzysmygod]
#12520850 - 05/07/10 04:57 AM (14 years, 8 months ago) |
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anyone? no ones even told me off for bumping the thread so many times. its as if replys not working :p
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andymc
cocoa beetles from zanzibar



Registered: 11/25/09
Posts: 2,395
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Re: Building HEPA, a little help required. [Re: ozzysmygod]
#12520921 - 05/07/10 05:53 AM (14 years, 8 months ago) |
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I'm sure lots of us could make something up, but you wanted a TC who knows about the subject eh? Usually RR helps with these sorts of questions, so perhaps you just have to wait until he sees it.
-------------------- How I make spore prints
Trade List
My flow hood
If he asks me "Did you have a good time?" I'll say,
"Get the lights, Mr. Grim Reaper" -odds
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ozzysmygod
Late Night PC'ing Enthusiast



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Re: Building HEPA, a little help required. [Re: andymc]
#12520964 - 05/07/10 06:20 AM (14 years, 8 months ago) |
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Yup, sorry I guess I'm just being impatient. My HEPA arrives on wednesday, and Im hoping to get a blower ordered in time. I've seen lots of threads where a TC has confirmed blower/HEPA match.
Im just so excited about all the cloning, isolating, and exciting agar work thats coming up
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andymc
cocoa beetles from zanzibar



Registered: 11/25/09
Posts: 2,395
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Re: Building HEPA, a little help required. [Re: ozzysmygod]
#12520971 - 05/07/10 06:24 AM (14 years, 8 months ago) |
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Totally understandable.
Hey, could the filter manufacturer or a blower manufacturer give you the numbers you need? I guess you'd need to know the right air output speed/pressure that's appropriate for our purposes...
-------------------- How I make spore prints
Trade List
My flow hood
If he asks me "Did you have a good time?" I'll say,
"Get the lights, Mr. Grim Reaper" -odds
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Doc_T
Random Dude




Registered: 03/06/09
Posts: 42,395
Loc: Colorado
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Re: Building HEPA, a little help required. [Re: andymc]
#12520989 - 05/07/10 06:37 AM (14 years, 8 months ago) |
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Quote:
andymc said: Usually RR helps with these sorts of questions, so perhaps you just have to wait until he sees it. 
He does seem to know the most about the subject.
-------------------- You make it all possible. Doesn't it feel good?
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ozzysmygod
Late Night PC'ing Enthusiast



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Re: Building HEPA, a little help required. [Re: Doc_T]
#12521009 - 05/07/10 06:49 AM (14 years, 8 months ago) |
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i have got all the relevant numbers, the stats for the filter are in the image of the table, and the stats for the blower in the graph. according to fungifuns instructions they match, i just wanted confirmation. i will wait till the end of the weekend for a confirmation, if not i'll by it anyway, im pretty sure i got the math right
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RogerRabbit
Bans for Pleasure


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Re: Building HEPA, a little help required. [Re: ozzysmygod]
#12521119 - 05/07/10 07:37 AM (14 years, 8 months ago) |
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I only have a few minutes per day lately to answer questions so I've been passing by this one since I've shown the math in many other threads. You'll need to convert the cubic meters per hour to cubic feet per minute so you're working with the same measurements.
You want +/- 100 linear feet per minute leaving the face of your flowhood. In other words, an airspeed of 100 fpm. This is enough to bend a flame over 45 to 80 degrees, but not flicker or blow it out.
A 1 square foot flowhood would want a 100 cfm blower at .9 to 1.1" W.C. in a perfect world without friction or losses from making turns, prefilter, etc. I add roughly ten to twenty percent to cover losses.
Your filter is 4 square feet, so you'd want 400 cubic feet per minute(cfm) in that same perfect world. I'd suggest a blower in the range of 450 to 550 cfm @ .9" to 1.1" of water column(WC) static pressure. 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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ozzysmygod
Late Night PC'ing Enthusiast



Registered: 11/26/08
Posts: 835
Last seen: 10 years, 2 months
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Re: Building HEPA, a little help required. [Re: RogerRabbit]
#12521739 - 05/07/10 11:23 AM (14 years, 8 months ago) |
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Thanks RR for clearing that up muchly appreciated. I have now found a blower suitable. A week today (14th of may) I should have my constructed HEPA filter.
I will be building them and selling them if any one is interested.
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ozzysmygod
Late Night PC'ing Enthusiast



Registered: 11/26/08
Posts: 835
Last seen: 10 years, 2 months
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Re: Building HEPA, a little help required. [Re: ozzysmygod]
#12560724 - 05/14/10 08:19 AM (14 years, 8 months ago) |
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Okay so the HEPA filter arrived and they sent me a 12" thick one not a 6" one. Idiots! They're going to send out a new one and pick up the old one. However i'm a bit stumped. The 12" Thick filter has a pressure drop of 140 pA. I questioned this as the data sheets list it as 250 pA and they replied that the pressure drop vary's from filter to filter. I already bought a blower suitable for a pressure drop of 250 pA, what should I do??
Thanks
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