Home | Community | Message Board


This site includes paid links. Please support our sponsors.


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 members-only content. You'll gain access to additional forums, file attachments, board customizations, encrypted private messages, and much more!

Shop: North Spore Cultivation Supplies   Mushroom-Hut Substrate Mix   Left Coast Kratom Buy Kratom Extract   PhytoExtractum Maeng Da Thai Kratom Leaf Powder

Jump to first unread post Pages: < Back | 1 | 2 | 3 | 4 | 5 | 6 | Next >  [ show all ]
Some of these posts are very old and might contain outdated information. You may wish to search for newer posts instead.
Invisibleblindingleaf
blue collar underworld
 User Gallery

Registered: 07/19/13
Posts: 22,008
Loc: sub-surface unseen
Trusted Cultivator
Re: Laminar Flow Hood Calculations [Re: Jack Why]
    #23143727 - 04/22/16 09:22 AM (7 years, 11 months ago)

So in ur opinion, it would be impossible for filter media to be damaged from a plenum too small and blower too powerful?


--------------------
A few thoughts on cultivation
MICROBIAL HUSBANDRY!!!!

The whole is greater than the sum of its parts

Extras: Filter Print Post Top
Offlinemushpunx
Fungus Punk
 User Gallery


Registered: 04/20/14
Posts: 13,394
Last seen: 1 month, 20 days
Trusted Cultivator
Re: Laminar Flow Hood Calculations [Re: blindingleaf]
    #23144414 - 04/22/16 01:59 PM (7 years, 11 months ago)

I dunno man for the home cultivator building thier own hood I think its a pretty good rule of thumb to build a plenum at least as deep as the filter is


--------------------

Amateur Mycologists United
AMU Q&A

Extras: Filter Print Post Top
OfflineJack Why
Stranger
Male
Registered: 06/24/12
Posts: 34
Last seen: 7 years, 10 months
Re: Laminar Flow Hood Calculations [Re: blindingleaf]
    #23149407 - 04/24/16 06:52 AM (7 years, 10 months ago)

Quote:

blindingleaf said:
So in ur opinion, it would be impossible for filter media to be damaged from a plenum too small and blower too powerful?





the only real aerodynamic function of a plenum is to minimize the kinetic energy of the flow.  the manufacturer specs tell u the maximum pressure/flow, don't exceed those and don't point the blower at the filter. the filter will be fine.


--------------------
until u know why, you don't know jack.

Grant me the strength to change the things i can,
the serenity to endure those i can not,
and the wisdom to hide well the bodies
of those who try to tell me the difference.

Extras: Filter Print Post Top
Invisibleblindingleaf
blue collar underworld
 User Gallery

Registered: 07/19/13
Posts: 22,008
Loc: sub-surface unseen
Trusted Cultivator
Re: Laminar Flow Hood Calculations [Re: Jack Why]
    #23149424 - 04/24/16 07:11 AM (7 years, 10 months ago)

so lets say u have two identical filters, and two identical blowers that are matched to spec.

u make two hoods.  one hood has a 6" plenum, the other has a 12"plenum, otherwise the hoods are identical.

would you anticipate differences between the two in terms of flow rate across the filter face?


--------------------
A few thoughts on cultivation
MICROBIAL HUSBANDRY!!!!

The whole is greater than the sum of its parts

Extras: Filter Print Post Top
Invisibleblindingleaf
blue collar underworld
 User Gallery

Registered: 07/19/13
Posts: 22,008
Loc: sub-surface unseen
Trusted Cultivator
Re: Laminar Flow Hood Calculations [Re: blindingleaf]
    #23149428 - 04/24/16 07:16 AM (7 years, 10 months ago)

in my experience, this is what happens when ur plenum is not large enough, even when urblower is matched to the filter size, so i don't agree that plenum size is not important



there is much more turbulence at the bottom of the box when ur plenum is too shallow, and can blow out the filter media over time


--------------------
A few thoughts on cultivation
MICROBIAL HUSBANDRY!!!!

The whole is greater than the sum of its parts

Extras: Filter Print Post Top
OfflineJack Why
Stranger
Male
Registered: 06/24/12
Posts: 34
Last seen: 7 years, 10 months
Re: Laminar Flow Hood Calculations [Re: mushpunx]
    #23149573 - 04/24/16 08:33 AM (7 years, 10 months ago)

Quote:

mushpunx said:
I dunno man for the home cultivator building thier own hood I think its a pretty good rule of thumb to build a plenum at least as deep as the filter is




filter thickness has absolutely no relationship to the distance required from the filter to the rear of the plenum or anything else.
why are you making up a rule of thumb for a relationship that doesn't exist?  that's how myth and superstition come into being.  I know you try to help others learn (that's what i'm trying to do as well),imo you just need to be a little more skeptical about what you accept as fact before sharing it with others.


--------------------
until u know why, you don't know jack.

Grant me the strength to change the things i can,
the serenity to endure those i can not,
and the wisdom to hide well the bodies
of those who try to tell me the difference.

Extras: Filter Print Post Top
Invisibleblindingleaf
blue collar underworld
 User Gallery

Registered: 07/19/13
Posts: 22,008
Loc: sub-surface unseen
Trusted Cultivator
Re: Laminar Flow Hood Calculations [Re: Jack Why]
    #23149610 - 04/24/16 08:52 AM (7 years, 10 months ago)

well thats why its called a "rule of thumb" because all of us un educated lowly mushroom growers don't have anywhere near the wisdom that engineers do

Quote:


"Rule of Thumb"
noun
1.  a general or approximate principle, procedure, or rule based on experience or practice, as opposed to a specific, scientific calculation or estimate.

2.  a rough, practical method of procedure.




so we have to rely on and draw from the vast amount of experience from cultivators that have come before, and in this case, their experiences showed that, in general, it is a good idea to build a plenum that is equal to or greater than the depth of the filter itself.  over time, a "rule of thumb" was born.


--------------------
A few thoughts on cultivation
MICROBIAL HUSBANDRY!!!!

The whole is greater than the sum of its parts

Extras: Filter Print Post Top
OfflineJack Why
Stranger
Male
Registered: 06/24/12
Posts: 34
Last seen: 7 years, 10 months
Re: Laminar Flow Hood Calculations [Re: blindingleaf]
    #23149616 - 04/24/16 08:56 AM (7 years, 10 months ago)

the blowers were on top blowing down, right?


--------------------
until u know why, you don't know jack.

Grant me the strength to change the things i can,
the serenity to endure those i can not,
and the wisdom to hide well the bodies
of those who try to tell me the difference.

Extras: Filter Print Post Top
Invisibleblindingleaf
blue collar underworld
 User Gallery

Registered: 07/19/13
Posts: 22,008
Loc: sub-surface unseen
Trusted Cultivator
Re: Laminar Flow Hood Calculations [Re: Jack Why]
    #23149695 - 04/24/16 09:36 AM (7 years, 10 months ago)

yes


--------------------
A few thoughts on cultivation
MICROBIAL HUSBANDRY!!!!

The whole is greater than the sum of its parts

Extras: Filter Print Post Top
Offlinemushpunx
Fungus Punk
 User Gallery


Registered: 04/20/14
Posts: 13,394
Last seen: 1 month, 20 days
Trusted Cultivator
Re: Laminar Flow Hood Calculations [Re: blindingleaf]
    #23149760 - 04/24/16 10:13 AM (7 years, 10 months ago)

Quote:

blindingleaf said:
well thats why its called a "rule of thumb" because all of us un educated lowly mushroom growers don't have anywhere near the wisdom that engineers do

Quote:


"Rule of Thumb"
noun
1.  a general or approximate principle, procedure, or rule based on experience or practice, as opposed to a specific, scientific calculation or estimate.

2.  a rough, practical method of procedure.




so we have to rely on and draw from the vast amount of experience from cultivators that have come before, and in this case, their experiences showed that, in general, it is a good idea to build a plenum that is equal to or greater than the depth of the filter itself.  over time, a "rule of thumb" was born.





Hah yea that's what Im saying Leaf. And if you are mounting a squirrel cage blower on top and behind a filter you're gunna need about 6" to fit the mouth of the blower anyways.

Most of us probably arent gunna cut it as engineers but we can do simple math to match a blowrr to a filter, and build a rectangular box. If you can do those two things, you can build a flow hood that works well for mycology :shrug:


--------------------

Amateur Mycologists United
AMU Q&A

Extras: Filter Print Post Top
OfflineJack Why
Stranger
Male
Registered: 06/24/12
Posts: 34
Last seen: 7 years, 10 months
Re: Laminar Flow Hood Calculations [Re: blindingleaf]
    #23149790 - 04/24/16 10:22 AM (7 years, 10 months ago)

Quote:

blindingleaf said:
in my experience, this is what happens when ur plenum is not large enough, even when urblower is matched to the filter size, so i don't agree that plenum size is not important



there is much more turbulence at the bottom of the box when ur plenum is too shallow, and can blow out the filter media over time





that was caused by the kinetic energy of blower air discharge.  when the air hits a dead end, 2 high pressure areas are created.  this pressure was added to the static pressure and blew the filter.  you could prevent that by making an 8' cube plenum, i'd like to see the rule of thumb for that.  or you could kill the kinetic energy with baffles, screens, fiberfill, etc.  its like misting your fruiting chamber with a fire hose, u shoot over their heads but the kinetic energy hits the side and makes mushed mushies.

as I said before;

"the only real aerodynamic function of a plenum is to minimize the kinetic energy of the flow.  the manufacturer specs tell u the maximum pressure/flow, don't exceed those and don't point the blower at the filter. the filter will be fine. "


--------------------
until u know why, you don't know jack.

Grant me the strength to change the things i can,
the serenity to endure those i can not,
and the wisdom to hide well the bodies
of those who try to tell me the difference.

Extras: Filter Print Post Top
InvisibleSupalemonhaze
Spore syringe hater.
Male


Registered: 10/02/15
Posts: 6,725
Loc: 12" down Europe's butthole
Re: Laminar Flow Hood Calculations [Re: Jack Why]
    #23149837 - 04/24/16 10:44 AM (7 years, 10 months ago)

You know when I was showing my build to my brother in law he asked if I used anything to diffuse the airflow, like you said. I looked at him like

:freshwtf:

and he looked back like

:justno:

Guess that is what he was trying to say to me. He is an electrical engineer and by no means an expert on fluid dynamics but he sees similar stuff in his profession.

Extras: Filter Print Post Top
OfflineJack Why
Stranger
Male
Registered: 06/24/12
Posts: 34
Last seen: 7 years, 10 months
Re: Laminar Flow Hood Calculations [Re: blindingleaf]
    #23150030 - 04/24/16 12:11 PM (7 years, 10 months ago)

Quote:

blindingleaf said:
well thats why its called a "rule of thumb" because all of us un educated lowly mushroom growers don't have anywhere near the wisdom that engineers do

Quote:


"Rule of Thumb"
noun
1.  a general or approximate principle, procedure, or rule based on experience or practice, as opposed to a specific, scientific calculation or estimate.

2.  a rough, practical method of procedure.




so we have to rely on and draw from the vast amount of experience from cultivators that have come before, and in this case, their experiences showed that, in general, it is a good idea to build a plenum that is equal to or greater than the depth of the filter itself.  over time, a "rule of thumb" was born.




you missed a critical aspect.

a "Rule of Thumb"  is derived by someone who KNOWS the subject.

otherwise what u have is a "rule of thumb up your azz."

false modesty, sarcasm, condescendence, arrogance, and ignorance wow you're the full package.  gloating about your ignorance is really attractive.

BEFORE YOU TRY TO EDUCATE OTHERS,EDUCATE YOURSELF!

u could start by losing the attitude and asking a civil question. i will explain the physics.

new "Rule of Thumb"= there is ABOLUTELY NO CORELATION BETWEEN THE THICKNESS OF THE FILTER AND THE DISTANCE FROM THE FILTER TO THE PLENUM WALL.  but you can use the phase of the moon plus 1' if you like, it will work as well as yours.

Extras: Filter Print Post Top
Offlinespacechildo
proletarians rise up
Male User Gallery

Registered: 01/24/13
Posts: 19,243
Loc: Babylon
Last seen: 6 years, 6 months
Re: Laminar Flow Hood Calculations [Re: Jack Why]
    #23150033 - 04/24/16 12:12 PM (7 years, 10 months ago)

:facepalm:

yeah leaf was truly showing his arrogance there, wow..:rolleyes:

Extras: Filter Print Post Top
Invisibleblindingleaf
blue collar underworld
 User Gallery

Registered: 07/19/13
Posts: 22,008
Loc: sub-surface unseen
Trusted Cultivator
Re: Laminar Flow Hood Calculations [Re: spacechildo]
    #23150116 - 04/24/16 12:49 PM (7 years, 10 months ago)

I'm the worst ain't I?


--------------------
A few thoughts on cultivation
MICROBIAL HUSBANDRY!!!!

The whole is greater than the sum of its parts

Extras: Filter Print Post Top
Offlinespacechildo
proletarians rise up
Male User Gallery

Registered: 01/24/13
Posts: 19,243
Loc: Babylon
Last seen: 6 years, 6 months
Re: Laminar Flow Hood Calculations [Re: blindingleaf]
    #23150130 - 04/24/16 12:56 PM (7 years, 10 months ago)

20k posts of arrogance and snide remarks hidden behind a wall of friendliness and helpful advice,
good thing we have well balanced members, and also our first ever engineer here, like jack showing us what you're really like leaf!
:lolsy:

Extras: Filter Print Post Top
OfflineJack Why
Stranger
Male
Registered: 06/24/12
Posts: 34
Last seen: 7 years, 10 months
Re: Laminar Flow Hood Calculations [Re: blindingleaf]
    #23150137 - 04/24/16 12:58 PM (7 years, 10 months ago)

Quote:

blindingleaf said:
so lets say u have two identical filters, and two identical blowers that are matched to spec.

u make two hoods.  one hood has a 6" plenum, the other has a 12"plenum, otherwise the hoods are identical.

would you anticipate differences between the two in terms of flow rate across the filter face?




as long as both keep the kinetic energy to reasonable levels, they would perform the same.


--------------------
until u know why, you don't know jack.

Grant me the strength to change the things i can,
the serenity to endure those i can not,
and the wisdom to hide well the bodies
of those who try to tell me the difference.

Edited by Jack Why (04/24/16 04:18 PM)

Extras: Filter Print Post Top
OfflineJack Why
Stranger
Male
Registered: 06/24/12
Posts: 34
Last seen: 7 years, 10 months
Re: Laminar Flow Hood Calculations [Re: Supalemonhaze]
    #23150257 - 04/24/16 01:57 PM (7 years, 10 months ago)

Quote:

Supalemonhaze said:
You know when I was showing my build to my brother in law he asked if I used anything to diffuse the airflow, like you said. I looked at him like

:freshwtf:

and he looked back like

:justno:

Guess that is what he was trying to say to me. He is an electrical engineer and by no means an expert on fluid dynamics but he sees similar stuff in his profession.




yup, for the same reason we don't point the blower discharge at the filter.  even if the velocity is low enough to not damage the filter
the kinetic energy will cause "hot spots", areas of higher velocity out of the filter. you can use sheet metal baffles, screens, egg crate anything to break up that column of moving air.


--------------------
until u know why, you don't know jack.

Grant me the strength to change the things i can,
the serenity to endure those i can not,
and the wisdom to hide well the bodies
of those who try to tell me the difference.

Extras: Filter Print Post Top
Offlinemushpunx
Fungus Punk
 User Gallery


Registered: 04/20/14
Posts: 13,394
Last seen: 1 month, 20 days
Trusted Cultivator
Re: Laminar Flow Hood Calculations [Re: Jack Why]
    #23150263 - 04/24/16 02:00 PM (7 years, 10 months ago)

Jack Why I have an idea. .
Maybe donate a little bit of your time to a written up guide for the layman.

Many of us have managed to build working laminar flow cabinets worthy enough to hold thier own in small spawn labs, without the benifit of experience or an engineering degree with the few guides we have available to us. I know that's all I was really after..


If you think you can present a write up guide to improve our builds in layman terms then by all means please do. It would certainly be quite welcome on this forum.

I mean if these were *that* hard to design in the first place most of our hoods wouldn't work for mycology.


--------------------

Amateur Mycologists United
AMU Q&A

Extras: Filter Print Post Top
OfflineJack Why
Stranger
Male
Registered: 06/24/12
Posts: 34
Last seen: 7 years, 10 months
Re: Laminar Flow Hood Calculations [Re: mushpunx]
    #23150789 - 04/24/16 05:10 PM (7 years, 10 months ago)

Quote:

mushpunx said:
Jack Why I have an idea. .
Maybe donate a little bit of your time to a written up guide for the layman.

Many of us have managed to build working laminar flow cabinets worthy enough to hold thier own in small spawn labs, without the benifit of experience or an engineering degree with the few guides we have available to us. I know that's all I was really after..


If you think you can present a write up guide to improve our builds in layman terms then by all means please do. It would certainly be quite welcome on this forum.

I mean if these were *that* hard to design in the first place most of our hoods wouldn't work for mycology.




kool, I was trying to draft one here; 

https://www.shroomery.org/forums/showflat.php/Number/23089477
is this the wrong place for such a thing?
you guys can help by telling me what needs further explanation, questions, topics, etc.

I've learned tons about mycology from you guys and would like to return the favor.


--------------------
until u know why, you don't know jack.

Grant me the strength to change the things i can,
the serenity to endure those i can not,
and the wisdom to hide well the bodies
of those who try to tell me the difference.

Extras: Filter Print Post Top
Jump to top Pages: < Back | 1 | 2 | 3 | 4 | 5 | 6 | Next >  [ show all ]

Shop: North Spore Cultivation Supplies   Mushroom-Hut Substrate Mix   Left Coast Kratom Buy Kratom Extract   PhytoExtractum Maeng Da Thai Kratom Leaf Powder


Similar ThreadsPosterViewsRepliesLast post
* Laminar Flow Hood Questions haxjester 2,475 6 02/16/08 05:26 PM
by FooMan
* Relatively Poor Mans Laminar Flow hood stinkbuttdog 14,522 13 08/08/07 06:52 AM
by RogerRabbit
* laminar flow hood - getting started zachv15165 5,857 5 12/15/08 05:54 PM
by Mephistophelian
* Laminar Flow hood... non-handy person building it himself? lsg1 1,773 5 05/16/07 10:01 AM
by Brainiac
* Can you use a Walmart bought Air Purifier - in place of a Laminar Flow Hood?
( 1 2 all )
JoeSmoe 16,423 21 12/30/09 11:50 AM
by Cordyceps
* Homemade Keeps the fuggn Contams out Flow Hood or PPGB
( 1 2 3 all )
Aztek 12,742 48 01/05/09 12:18 AM
by fastfred
* Homemade "Laminar" flow hood
( 1 2 all )
The shroomy 1 35,411 24 08/15/08 04:58 AM
by Ogre812
* Laminar flow hood, self-made or new purchase?
( 1 2 all )
MichaelH 20,050 20 02/20/14 11:27 PM
by MyloPsybe

Extra information
You cannot start new topics / You cannot reply to topics
HTML is disabled / BBCode is enabled
Moderator: Shroomism, george castanza, RogerRabbit, veggie, mushboy, fahtster, LogicaL Chaos, 13shrooms, Stipe-n Cap, Pastywhyte, bodhisatta, Tormato, Land Trout, A.k.a
14,447 topic views. 33 members, 144 guests and 89 web crawlers are browsing this forum.
[ Show Images Only | Sort by Score | Print Topic ]
Search this thread:

Copyright 1997-2024 Mind Media. Some rights reserved.

Generated in 0.028 seconds spending 0.01 seconds on 15 queries.