Welcome to the Shroomery Message Board! You are experiencing a small sample of what the site has to offer. Please login or register to post messages and view our exclusive membersonly content. You'll gain access to additional forums, file attachments, board customizations, encrypted private messages, and much more!

MushroomMarkk
Stranger
Registered: 01/25/05
Posts: 138
Last seen: 2 years, 4 months

Flowhood box
#4229947  05/28/05 02:23 PM (11 years, 9 months ago) 


Alright, im tryin to make a flowhood so i can get some more efficient agar work goin. I have found a 24x24x11.5 inch nuclear grade hepa that is 99.9% effective. It does tell teh static pressure of the filter, and i dont know hwo to figure that out. i have also found this blower http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=3101&item=8194440929&rd=1 would these 2 work together, or could someone tell me how to calculate static pressure. Thank you

HippieChick
Chicks can do it too!
Registered: 02/20/05
Posts: 5,958
Loc: Midwest
Last seen: 3 months, 14 days


Check Stamet's TMC page 347.
Peace,Love,Happiness and Harmony. Hippie Chick
 Peace,Love and Happiness
HC
Freedoms just another word for nothing left to lose..............
I LUV My Greenhouse
http://www.shroomery.org/forums/showflat.php/Number/5545848#5545848
My First Pans
http://www.shroomery.org/forums/showflat.php/Number/6212058#6212058

deanofmean
mycophagous
Registered: 12/07/02
Posts: 2,017
Loc: PNW



ohmatic
searcher
Registered: 02/28/04
Posts: 6,742
Loc: europe


quoted from [url=http://http://www.fungifun.org/flowhood/match.htm ]http://www.fungifun.org/flowhood/match.htm [/url]
Quote:
Matching a blower to the filter According to Stamets (Paul Stamets and J.S.Chilton: The Mushroom Cultivator p. 347 ff) the air speed of the air flowing from the filter surface should be (at least) 100 feet per minute(fpm).(around 30 meter per minute or 0.5 meter per second). Determining the correct blower for a filter consists of several steps:
1. Find out the area of your filter by multiplying the width and the hight in feet (for instance the smallest reasonably usable filter would be 2ft x 1ft)
2ft x 1ft = 2 ft2
2. Multiply the required air speed(the one Stamets specifies, 100 ft/min) with the area of your filter
100 ft/min x 2 ft2 = 200 ft3/min
So 200 ft3/min(= cfm = "cubic feet per minute") is the amount of air your blower must deliver at the sum of the STATIC PRESSURE of the HEPA filter + prefilter.
NOTE: 1 cfm= 1.7m3/h
So if you use the above filter with 1"(250Pa) static pressure and a furnace prefilter with a static pressure of 0.2"(50Pa) your blower must deliver 200 cfm(340m3/h) of air at a static pressure of 1.2"(300Pa).
Finding the correct blower Every blower should have a data sheet with a characterisitc curve that shows the air output in dependance of the static pressure. Every blower has a data sheet (consult the manufacturer if this is not the case with your blower) where the correlation between the flow and the static pressure is represented by a graph or table.
Here is such a set of curves for 4 blowers(numbered 14). NOTE: Each model of a blower has his own characteristical curve. This chart shows the curvers for 4 different particular models of axial duct blowers. What you can clearly see is that the bigger the static pressure the less air the blower delivers, up to the maximum static pressure where the air output is zero.
Sometimes these data are presented in form of a table
By now you know how much your blower must deliver and at which static pressure. In our example it was 340m3/h at 300Pa. So what we do now is to go in this chart and find the value of 300Pa(=1.2") at the vertical axis. Then you move to the right until you reach 340m3/h.(=200cfm) Now, ideally there should be a curve of a blower going exactly trough this point, but this is not allways the case. So we have to choose a blower that best approximates our requirements. In most cases we should choose a stronger blower, if it's not too strong. How strong is too strong? I?d say the blower shouldn?t deliver more that 20% more air than we calculated, so in our case the strongest acceptable blower would be around 400m3/h. In this example we have a blower that delivers 300m3/h(according to our calculation it should deliver 340m3/h though). This is a difference of mere 10%. The next stronger blower in this chart delivers 530m3/h at 300Pa, which is way too much.
In this case we go for the smaller(and cheaper) blower(Nr.4) instead of the much bigger one(Nr.1, which delivers 530m3/h at 300Pa), despite the fact that it?s generally recomended to take a stronger one.
NOTE: This chart is only an example for a set of 4 particular blowers. The curves of the blowers available to you may look a bit different, but similar. Usually, if you search long enough, you will be able to find a blower that exactly matches your HEPA.
peace ohm
 MONOTUB tek HEATBOMB tek
RIP #cultivation! ....can't associate? well FUCK U !

mattymonkey
Feel Like aStranger...
Registered: 11/07/04
Posts: 973
Last seen: 4 years, 2 months


those blowers that samgreat sells on ebay are great btw, he does a good job...
 "listening for the secret.. searching for the sound.."

MushroomMarkk
Stranger
Registered: 01/25/05
Posts: 138
Last seen: 2 years, 4 months


the blower on ebay doesnt have a chart. But considering it is a 1000cfm blower, shouldnt it work? It seems like it would be atleast pwoerful enough, if not too powerful, anyway, what the problem with too much power? thanx for the input guys

ohmatic
searcher
Registered: 02/28/04
Posts: 6,742
Loc: europe


throughput isnt everythnig, you need a certain static pressure buildup in order to guarantee proper laminar flow. peace ohm
 MONOTUB tek HEATBOMB tek
RIP #cultivation! ....can't associate? well FUCK U !

MushroomMarkk
Stranger
Registered: 01/25/05
Posts: 138
Last seen: 2 years, 4 months

Re: Flowhood box [Re: ohmatic]
#4230516  05/28/05 05:49 PM (11 years, 9 months ago) 


alright hows this look, http://cgi.ebay.com/ws/eBayISAPI.dll?Vie...ssPageName=WDVW 600cfm blower, with this filter http://cgi.ebay.com/ws/eBayISAPI.dll?Vie...ssPageName=WDVW that should be pretty close to accurate, if not being a little bit overpowered
That might be a little too much power, so i could drop it down to 465cfm blower, and eitehr the 465 or the 600 has got to be the one! Crap at fungiperfecti they have a 1092cfm at .8" static pressure blower that they say is perfect for a 24x24 hepa. For some reason that seems overpowered because a 24x24 should only need a 400cfm, not including static pressure. Wow dammit im so confused by this stuff, should i get a 1000cfm or a 600cfm, im guessing now that the 465 cfm is too small. I wish i knew the static pressure of my filter
Edited by MushroomMarkk (05/28/05 10:08 PM)
 


You cannot start new topics / You cannot reply to topics HTML is disabled / BBCode is enabled
Moderator: Magash, Shroomism, george castanza, Prisoner#1, RogerRabbit, Citric, total, FooMan, 13shrooms, stonesun, EvilMushroom666, cronicr, PussyFart, Tmethyl 920 topic views. 8 members, 44 guests and 14 web crawlers are browsing this forum.
[ Toggle Favorite  Print Topic  Stats ]
  


