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pshawny
Mycobian



Registered: 09/11/04
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Flowhood design question
#4253766 - 06/03/05 08:05 PM (18 years, 11 months ago) |
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I'm going to have a 2'x4' hepa filter to build a flowhood around and want some advice. I want a clean look to it, thus wanting to have the blower mounted inside the plenum area like in the picture. Will it be okay to have the blower in there like that or should it be mounted on top?
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ThumpaCap
Beer Taster

Registered: 02/19/05
Posts: 568
Loc: Shroomwhere Out There
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Re: Flowhood design question [Re: pshawny]
#4254294 - 06/03/05 10:42 PM (18 years, 11 months ago) |
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if you can filter the air before it enters the fan it would prob be easier to keep clean
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pshawny
Mycobian



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Re: Flowhood design question [Re: ThumpaCap]
#4254354 - 06/03/05 11:01 PM (18 years, 11 months ago) |
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There will be a pre-filter on the blower intake.
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tahoe
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Re: Flowhood design question [Re: pshawny]
#4254491 - 06/03/05 11:48 PM (18 years, 11 months ago) |
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-------------------- Stop experimenting half way through your first grow. Grow it to maturity, watch it, learn from it. Do this a few times then experiment with different ideas and figure out what works best for you.
My Legacy https://www.shroomery.org/forums/showflat.php/Number/22140987#22140987 Teh=The I need to proofread
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pshawny
Mycobian



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Re: Flowhood design question [Re: tahoe]
#4254528 - 06/04/05 12:01 AM (18 years, 11 months ago) |
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Looks like you've been busy. Have you ran into any problems during construction or is everything falling into place perfectly?
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xburn
V card
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Re: Flowhood design question [Re: pshawny]
#4255044 - 06/04/05 03:10 AM (18 years, 11 months ago) |
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fan on the inside will affect your plenum size so just make sure its big enough.
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RogerRabbit
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Re: Flowhood design question [Re: xburn]
#4256527 - 06/04/05 04:10 PM (18 years, 11 months ago) |
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You don't intend for your filter to be above the work area do you? You want the filter to be behind the work area, blowing directly towards you. That way you can prioritize things by level of sterility. If your blower blows straight down, it will have to turn a 90 degree turn to get out, and this will cause turbulence, thus destroying any laminar flow. Perhaps I just read your drawing wrong. 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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mattymonkey
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Re: Flowhood design question [Re: RogerRabbit]
#4256807 - 06/04/05 05:55 PM (18 years, 11 months ago) |
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i thought you wanted the fan to be blowing down and turning 90 degrees? that is how all the flow hoods i have seen are setup. am i misunderstanding?
Here is a pic of one from FP where you can see the fan, all metal encasing underneath, not the best design as it doesn't leave the fan enclosed so you dont have the ability for a prefilter... http://fungi.com/tools/toolpics/airfilters/lfh1.jpg
Here is another pic of one enclosed in wood, the prefilter is on the back of the upper part, the fan is in the upper part blowing strait down.. http://fungi.com/tools/toolpics/airfilters/lfh4.jpg
The fan blows strait down so you get an even flow of air threwout the entire filter.
Building a Homemade HEPA System Here is a tek for building your own that also recommends this setup.
peace, hope this helped
-------------------- "listening for the secret.. searching for the sound.."
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pshawny
Mycobian



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Re: Flowhood design question [Re: RogerRabbit]
#4256869 - 06/04/05 06:12 PM (18 years, 11 months ago) |
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I was planning to have the hepa above the work area. It doesn't have to be. I was just trying to build up instead of out, just a space issue. I'm thinking I want it to look somewhat like agar's flowhood. Is a vertical flowhood not going to work as well as a horizontal flowhood?
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Anand
AutisticShroomer


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Re: Flowhood design question [Re: pshawny]
#4258484 - 06/05/05 01:35 AM (18 years, 11 months ago) |
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I build mine with a horizontal filter and got some problems with air getting stuck at the lower back corner.... tested it with confetti.
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RogerRabbit
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Re: Flowhood design question [Re: Anand]
#4262756 - 06/06/05 07:33 AM (18 years, 11 months ago) |
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You really want your flow hood filter to be facing you as you work, not above your work area. If the filter is above your work area, it blows straight down, creating eddies and turbulence which could blow contaminants from your hands and arms into your sterile work. If the flowhood is at the back of your work area blowing towards you, laminar flow can result preventing that problem. 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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shobimono
Why?
Registered: 09/14/04
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Re: Flowhood design question [Re: RogerRabbit]
#4262942 - 06/06/05 09:21 AM (18 years, 11 months ago) |
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So you can have the blower blowing air down, as long as the filter is facing you?
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RogerRabbit
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Re: Flowhood design question [Re: shobimono]
#4263131 - 06/06/05 10:39 AM (18 years, 11 months ago) |
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Yes. It matters not which way your blower is facing, because its main job is to provide static pressure to the plenum behind the HEPA. Very little air flows through the filter because of the resistance. Without the HEPA filter, the fan would blast you in the face. With the flow hood filter in place, you can light a cig lighter in front of the flow hood and the flame should bend over, but not blow out. You can test for laminar flow by moving the cig lighter around to different areas of your work space. It should be uniformly bent over and not be flickering side to side. It should blow straight back anywhere in the airflow. 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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mattymonkey
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Re: Flowhood design question [Re: RogerRabbit]
#4263743 - 06/06/05 01:38 PM (18 years, 11 months ago) |
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nice tip
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agar
old hand


Registered: 11/21/04
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Re: Flowhood design question [Re: mattymonkey]
#4264671 - 06/06/05 05:36 PM (18 years, 11 months ago) |
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 OFF
 ON
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tahoe
Noob Slayer


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Re: Flowhood design question [Re: pshawny]
#4264756 - 06/06/05 06:04 PM (18 years, 11 months ago) |
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Quote:
pshawny said: Looks like you've been busy. Have you ran into any problems during construction or is everything falling into place perfectly?
I wont be able to finish her up until i get back from Ohio. Its a little big, its hard to picture something on paper. I might shorten the length and make it a little narrower. it depends on the filter size that i can find. I am useing a 12x12 hepa for this and the hepa will be in the middle and the air will then go through a larger filter to disperse the air into a wider stream
-------------------- Stop experimenting half way through your first grow. Grow it to maturity, watch it, learn from it. Do this a few times then experiment with different ideas and figure out what works best for you.
My Legacy https://www.shroomery.org/forums/showflat.php/Number/22140987#22140987 Teh=The I need to proofread
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pshawny
Mycobian



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Re: Flowhood design question [Re: tahoe]
#4267772 - 06/07/05 12:47 PM (18 years, 11 months ago) |
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Is a VLSI (Very Large Scale Integrated) filter the best kind of filter ?
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_blitzer
vintage user

Registered: 03/28/05
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Re: Flowhood design question [Re: agar]
#4267870 - 06/07/05 01:16 PM (18 years, 11 months ago) |
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Quote:
agar said:
 OFF
 ON
okay okay.......
do 'off' again?
-------------------- I'm laughing, but on the inside where you can't hear it.
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mycofile
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Re: Flowhood design question [Re: _blitzer]
#4268875 - 06/07/05 05:17 PM (18 years, 11 months ago) |
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I definitely agree with roger and others about the filter being vertical and blowing straight towards you. I have seen hoods that blow down, and I'm sure they offer benefits over unfiltered air, but a horizontal air flow is far superior so far as I'm concerned.
Also, I believe that it does matter which direction the fan blows into the plenum, but not much. As long as the fan blows in at a 90* angle to the filter, it will be fine. It matters not if it is coming from the top bottom, or either side. You just don't want to blow straight at the filter. This is to ensure that the plenum does it's job of evenly distributing the air across the filter.
pshawny, it looks from your drawing that you have the fan blowing directly at the filter, I would modify that if I were you. You can still have it inside the plenum if you want, just turn it so that it directs air toward a plenum wall rather than directly at the filter. Also, plenum size should be at least equal to the filter, so make sure you increase your plenum size to accomodate for the volume of the fan.
-------------------- "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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pshawny
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Re: Flowhood design question [Re: mycofile]
#4269355 - 06/07/05 07:27 PM (18 years, 11 months ago) |
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Okay, after reviewing everyone's thoughts I've decided to make some changes to the design. This should be much better.
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