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EvilMushroom666
Heretic




Registered: 11/18/09
Posts: 10,289
Loc: Canada
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Flowhood Help
#13327748 - 10/12/10 08:43 PM (13 years, 3 months ago) |
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It has been 3 weeks now since I have decided to build my own flowhood. During the last 3 weeks I have realized just how hard it is to source a filter within Canada . I finally got a hold of a company that can sell me a filter and have picked the filter linked below: http://www.tridim.ca/pdf/1700-1-HEPA-and-HEPAMAX.pdf
According to Fungi fun the math for my filter is as follows: http://www.fungifun.org/English/Flowhood
2ft X 2ft = 4ft squared 100ft/minX 4ft squared = 400 ft cubed/min
So I can therefor assume my blower must deliver 400CFM @ 1.2" W.C
This is were I get lost...as the spec sheet seems to have a much different resistance...
If you look at the spec sheet for the filter above, on the last page it has the following stats:
Tri-Pure HEPA Standard Cap model
Recommended Airflow = 250FPM(1.25 m/sec) Resistance 12" deep @ 250 FPM = 1" W.G (250 Pascals) 6" deep @ 125 FPM = 1" W.G (250 Pascals)
Using this site: http://www.scientifix.net/air-flow-conversions.html
I tried to convert FPM into CFM
A=24"X24" = 576 Square inches 576/144= 4 square feet
4 square feet X 250FPM = 1000 CFM 12" deep filter 4 square feet X 125FPM = 500 CFM 6" deep filter
I could be off 100% with all my calculations, math is my weakest area...but If I am can someone please explain what I did wrong...From my understanding If I get the above filter 24"X24"X12" I would need a 1000CFM blower to overcome the resistance, and would need 500CFM to overcome the resistance of the 6" depth filter... and this is only at 1" W.C...Ill need 1.2" with the prefilter...
Would you suggest a 24"X24"X12" filter OR 24"X24"X6"?
I am sorry if this all does not make sense or is way off... the more I read into building a hood, the more confusing things get...especially when dealing with a filter salesman who does not have any knowledge on using HEPA's for flowhoods...This is the one he recommended but Im pretty sure its expensive as shit and will not work as well for what I am planning. http://www.tridim.ca/pdf/1800-3-TRI-PURE-PANEL.pdf I feel lost someone please throw me a lifeline lol.
Edited by EvilMushroom666 (10/12/10 11:01 PM)
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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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Quote:
EvilMushroom666 said:
http://www.tridim.ca/pdf/1700-1-HEPA-and-HEPAMAX.pdf
2ft X 2ft = 4ft squared 100ft/minX 4ft squared = 400 ft cubed/min
In a perfect world, a 400 cfm motor would supply that much. However, blowers are not 100% efficient, and then there's the friction in the plenum, turbulence, etc. I usually add ten to twenty percent to that figure.
Quote:
Tri-Pure HEPA Standard Cap model
Recommended Airflow = 250FPM(1.25 m/sec) Resistance 12" deep @ 250 FPM = 1" W.G (250 Pascals) 6" deep @ 125 FPM = 1" W.G (250 Pascals)
A=24"X24" = 576 Square inches 576/144= 4 square feet
4 square feet X 250FPM = 1000 CFM 12" deep filter 4 square feet X 125FPM = 500 CFM 6" deep filter
Some of the newer HEPA filters flow higher than we want at 1" of static pressure. In these cases, you need to run at a lower static pressure, because you really don't want more than 100 feet per minute leaving your hood.
Based on the specs above, I'd go with the 6" deep filter because it has higher resistance. The resistance is what helps achieve laminar flow by creating pressure on the back side of the filter. If every inch of the back side is under pressure, the air flows smoothly out the front side.
I'd go with the 6" filter and a blower rated at 450 cfm @ 1" W.G. 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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EvilMushroom666
Heretic




Registered: 11/18/09
Posts: 10,289
Loc: Canada
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Thank you so much for the help, seems like I am not all that far off! The setup you described below should be fine without wanting the blower to be rated for 450CFM at 1.2" W.C(For the addition of a prefilter)? I am making a call tomorrow for a quote on the filter and appreciate your quick reply...might be a 4-6 week wait but im glad the ball is rolling.
While I have your attention RR I would also like to ask if you had a suggestion or opinion on the setup:
24"X24"X6" Tri Pure Hepa Rated at 99.97% at .03 With a Particle board OR plywood frame. Should the gasket seal be on the upstream,downstream, or both sides of the filter?
I want to make sure that I order exactly what I need.
Edited by EvilMushroom666 (10/12/10 11:14 PM)
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RogerRabbit
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Registered: 03/26/03
Posts: 42,214
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450 cfm at .8" to 1.2" W.G. is what you want for a blower.
The filter seals at the face to ensure nothing but filtered air enters your work space.
I'd go with plywood, not particle board. 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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EvilMushroom666
Heretic




Registered: 11/18/09
Posts: 10,289
Loc: Canada
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I am in the middle of getting a quote and was curious RR, what is your reasoning behind suggesting Plywood over particle board? It would be slighlty cheaper to get particle board and apparently it is more standard then plywood frames.
Just curous if its a preference thing, or a construction concern where plywood would be easier to seat,secure and seal.
As it stands:
24"X24"X6" Tri Pure HEPA 99.97 @ .03 micron Particle Board
4 week assembly time Cost: 171.50+HST = $194 Canadian Dollars
I feel this is more then fair and the gentleman I have been dealing with has been exceptionally helpful and professional. He is getting back to me later with information on the price difference to have it made using Plywood instead of particle board.
Just want to get another opinion from you before placing the deposit down to have it made. Thanks again for your help kind sir!
Edited by EvilMushroom666 (10/13/10 02:59 PM)
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EvilMushroom666
Heretic




Registered: 11/18/09
Posts: 10,289
Loc: Canada
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UPDATE: It is only avialable in Particle board. He has also located me a filter so I will not have to wait 4 weeks for it to be made. The only difference is that it is rated at 99.99 @ .03 micron, same size, same resistance, same price as the above quote. From my understanding it will not change what blower I need correct?
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RogerRabbit
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Registered: 03/26/03
Posts: 42,214
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Correct, and the reason I prefer plywood is because I wash the flowhood down so often with Lysol, alcohol, and other cleaners. Plywood will hold up better to the chemicals. 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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EvilMushroom666
Heretic




Registered: 11/18/09
Posts: 10,289
Loc: Canada
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Thanks for your help, put in the order today and I am getting it delivered free of charge late next week. Cheers! Thanks again
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EvilMushroom666
Heretic




Registered: 11/18/09
Posts: 10,289
Loc: Canada
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Had a few more questions. I am getting my HEPA tomorrow morning so I have been surfing around tonight trying to find a match for the blower I will require. I have found a motor that is within my price range and appears to be ok. It is linked here:
http://www.canadianwholesalehydroponics.com/products.cfm?p_id=2126&show_details=1&catpage=2 http://www.hydrofarm.com/pb_detail.php?itemid=6711
Its as you can see a 465CFM Blower used to vent grow rooms. I have spent a while looking for data sheets for this blower to see if it will give me the 465CFM at 1.0-1.2" W.C that I need but unfortunately the spec sheets do not include that data:
http://www.4hydro.com/growroom/manuals/activeAir.pdf
This brings me to my question. Can I go ahead and assume that this 465CFM blower puts out enough flow to bring me at least to the 0.8-1.2 " W.C that I need for my HEPA and prefilter? Is it something that is not that big of a deal or can a 465CFM blower operate at a wide variety of different static pressures?
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total
Post Office Tyvek Advocator




Registered: 10/03/04
Posts: 11,405
Last seen: 6 months, 22 days
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Absolutely not... If they dont list the blower is pumping 465CFM at 1.0WU, then you should assume thats in free air... You will need to match a blower to your filter... You need a blower that does alittle better than that acctually... A prefilter is said to increase your static pressure by .2, if your using one, you need a blower that does 465CFM@1.2WU... Thats quite a big blower  I was told by hydrofarm that the Vortex 12" inline provides 500CFM@1.0WU (acctually...i just checked my email, and he provided me with this LINK for all of the vortex fan graphs...that should give you what you'll need) I hope this helps...
Sorry i couldnt help you with a squirrel cage type... You can look on grainger.com to find one of those, they normally list static pressure...
Edited by total (10/21/10 12:03 AM)
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EvilMushroom666
Heretic




Registered: 11/18/09
Posts: 10,289
Loc: Canada
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Re: Flowhood Help [Re: total]
#13364782 - 10/21/10 12:12 AM (13 years, 3 months ago) |
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I do realize I need a blower of 450CFM at 1.2" W.C, I have contacted Vortex myself and the fan I got quoted was $400+ dollars. That is just not doable lol. The most I want to spend is $200, $150 if possible and the blower I listed above would be perfect price wise. Every other quote for a blower/fan operating at 450CFM @ 1.2" W.C has been $400+ the highest quote iv gotten being $697.
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total
Post Office Tyvek Advocator




Registered: 10/03/04
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Last seen: 6 months, 22 days
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They are going to be pricey... You might have better luck going around to hvac places around you and see if you can pickup a used one... 500cfm is alot of air to move at 1.2WU... Im scouting a $400 fan myself We are in the same boat...urgh goodluck
total
Edited by total (10/21/10 12:22 AM)
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EvilMushroom666
Heretic




Registered: 11/18/09
Posts: 10,289
Loc: Canada
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Re: Flowhood Help [Re: total]
#13365818 - 10/21/10 09:51 AM (13 years, 3 months ago) |
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Got the filter in today! One step closer to having it built!

Your looking at what $218 CDN gets you...I HOPE the blower I linked will work for this, going to try and track down the company and call them ask for data sheets or specs.
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darshan
perennial autodidact



Registered: 09/10/02
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Last seen: 4 years, 10 months
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You should really look on eBay. I was able to get an 800CFM blower (680CFM@.75") for $130US, shipped. Even had the data sheet. Granted it's used, but if you're going to find a bomber fan or blower that you can afford, prepare for it to be a used one.
I didn't try Agar's advice, though I should have, which is to call furnace repair shops in your area to see if they have blowers about that they can sell you. These are likely to be very hard-working units compared to a grow-room ventilator. I wish I had done this and I bet it's really the best route possible.
If you don't feel confident finding a viable blower on eBay, I would be willing to make a recommendation based on current searches myself.
I -just- built my hood and have been getting into agar and strain isolation from MS inoculation. Your hard work will pay off!!! It's super fun and gratifying. And it just makes a person feel cool to be working with proper equipment ( I always imagine Professor Frink from the Simpsons, or Dr. Farnsworth from Futurama, but then again I'm a huge-ass nerd ).
Good luck!
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darshan
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Registered: 09/10/02
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Re: Flowhood Help [Re: darshan]
#13369667 - 10/22/10 01:25 AM (13 years, 3 months ago) |
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Total is right, that blower will pretty much 100% not work.
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total
Post Office Tyvek Advocator




Registered: 10/03/04
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Re: Flowhood Help [Re: darshan]
#13369676 - 10/22/10 01:29 AM (13 years, 3 months ago) |
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EvilMushroom666
Heretic




Registered: 11/18/09
Posts: 10,289
Loc: Canada
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Re: Flowhood Help [Re: darshan]
#13370598 - 10/22/10 10:04 AM (13 years, 3 months ago) |
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I got looking into free air and talking to a few people. I now unfortunately realize that blower wont work. I got a couple people looking out for cage blowers for me, I am in no rush just waiting for that diamond in the rough that does not cost me $400. I would prefer free .99. Thanks for the input and advice guys.
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Mephistophelian
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Registered: 08/14/08
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Good luck on finding your Cage blower. It's the only way to go. They will work 100% as long as they are big enough. The place I went to (the HVAC company) had a store room actually full of them for $50 a piece if I wanted to buy one.
But like you and I discussed...I just jumped on opportunity and snagged mine out of a defunct furnace in a dumpster late one night. Checked the rough specs online then hooked it up to the filter and kept closing off one side until I had the air just right. It looks mega Ghetto but hey, it works right? And I paid 0 for it.
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RogerRabbit
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Registered: 03/26/03
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Scroll through these blowers. There's several that meet your needs. If in doubt, order a slightly larger one and either slow it down with a motor speed controller or block off part of the air intake. 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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total
Post Office Tyvek Advocator




Registered: 10/03/04
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Any luck? I found a SITE that sells Centrifugal Inlines and provides data charts for them...They are reasonably priced... Based on their data charts, you could get by with a 6"...but id buy a 8" just to make sure  By the way it looks, the 10" is exactly what i need!  They have a store on EBAY, and they state the following...
Quote:
30 Day 100% Money Back Guarantee! We stand by our fans so much that if your not happy with it within the first 30 days we will pay the shipping to return it and refund your purchase 100% We also pay shipping on all warrantied items!
I think im gonna give that 10" a go...I think it will more than power my 2"x4" hood... They also have Speed Controllers...
Edited by total (10/23/10 10:10 PM)
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