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PutACapInHisAss
Stranger Than Fiction



Registered: 08/11/07
Posts: 252
Loc: Earth
Last seen: 6 years, 4 months
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Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details...
#23620398 - 09/06/16 11:47 PM (7 years, 4 months ago) |
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What about the details of the build itself? What mistakes have you seen or made? What might you do differently if you built one again?
I've really put in serious time on flow hood research but now I'm down to the final design and build. I am highly confident that pre-filter, filter, and blower I've selected are appropriate and compatible. I am also going to have an actual hood instead of just a laminar flow box.
At this moment my plan is to make the plenum roughly twice the thickness of the main filter. This would be about 12" of plenum.
I'm thinking about going with thin plywood for the plenum and pre-filter boxes to reduce cost and weight. I will reinforce the inner seems with furring strips.
This will also allow me to build the hood so that the space enclosed will be closer to the actual dimensions of the media itself rather than the outer edges of the filter frame.
The idea is to keep the flow inside the hood as laminar as possible and not have dead space around the frame.
What say ye?
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Supalemonhaze
Spore syringe hater.



Registered: 10/02/15
Posts: 6,725
Loc: 12" down Europe's butthole
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: PutACapInHisAss]
#23620526 - 09/07/16 01:07 AM (7 years, 4 months ago) |
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Don't know about little details but you should definitely ditch the enclosure and reduce the plenum. I get that a hood will probably never have the need to be moved but you still need it to be as small and light as possible. The plenum being double the thickness of your filter is simply overkill and completely unnecessary.
As for the enclosure, I was pretty much sold on the idea as well when I was building mine. Thing is though, you opt for a flowhood so you will have space to work and not be restricted like you would be in a SAB. Building an enclosure will be counter productive. If you are not working in an especially drafty room and your flow is at least 100FPM, laminar flow is a guarantee (given that you build it correctly), you don't need an enclosure for that. If you really "have" to build an enclosure, only make it extend for ~6 inches or so, so you won't have to work in a box. The design of the hoods we use was made with the lack of enclosure in mind. Commercial hoods often have a "low" power setting which operates at 60fpm and since not having an enclosure is more comfortable, 100fpm is used to guarantee laminar flow without it.
The only other suggestion I can make is to plan well before you start cutting and assembling the wood. Draw everything on a piece of paper and double and triple measure everything, especially if you don't have any experience with woodwork.
Goodluck with your build.
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wtfcrazymofo
foil hater



Registered: 07/26/15
Posts: 1,201
Loc: Colonial alley
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: PutACapInHisAss]
#23620610 - 09/07/16 02:42 AM (7 years, 4 months ago) |
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Glue between plywood connections of hoodless box.
-------------------- If you want to eat->https://www.shroomery.org/forums/showflat.php/Number/8553541 Bag sealers are to bulky (my hood isn't that big) https://www.shroomery.org/forums/showflat.php/Number/28622922
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blindingleaf
blue collar underworld


Registered: 07/19/13
Posts: 22,008
Loc: sub-surface unseen
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: wtfcrazymofo]
#23620767 - 09/07/16 05:22 AM (7 years, 4 months ago) |
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-if ur hood is 2x2 or smaller, definitely don't enclose it unless the room you will use it in is dusty/dirty/questionable/heavily trafficked. its a work space issue (not open enough) but realistically, getting a bag sealer in there with you and your bags will be a bitch with an enclosure
-u can always add on an enclosure really easily with wood that would basically look like a cover for a pickup truck bed that can be removed whenever.
-coat ur wood with polyurethane after cutting it, and before assembling it. use 2 coats on inside and out.
-with the help of a friend, try to "dry fit" ur filter into the frame before nailing/assembling the box, just in case.
-pre filter boxes are cool, but I'm not sold on them as far as necessity or even in terms of the longevity of the unit…but go for it if u have time and resources.
-use filter stops lining inside of the box to "hold" filter there, instead of siliconing it permanently.
-make sure ur blower comes with a flange, or get the correct flange for mounting it. if they come separate, pay special attention to where they meet and silicone appropriately
-use window screen/hardware cloth/etc for a guard so u don't bump filter media (optional but worth it)
-------------------- A few thoughts on cultivation MICROBIAL HUSBANDRY!!!! The whole is greater than the sum of its parts
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spore-ty



Registered: 01/21/16
Posts: 1,028
Loc: In the bush
Last seen: 2 years, 10 months
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: blindingleaf]
#23620980 - 09/07/16 07:14 AM (7 years, 4 months ago) |
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Blidingleaf which filter would you reccommend a micron filter or a mini pleat micron filter?
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blindingleaf
blue collar underworld


Registered: 07/19/13
Posts: 22,008
Loc: sub-surface unseen
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: spore-ty]
#23620987 - 09/07/16 07:17 AM (7 years, 4 months ago) |
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either.
99.995%+ filtration is the important part. i read the mini pleats are better, probably increased surface area for filtration. mine is just regular pleat
-------------------- A few thoughts on cultivation MICROBIAL HUSBANDRY!!!! The whole is greater than the sum of its parts
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spore-ty



Registered: 01/21/16
Posts: 1,028
Loc: In the bush
Last seen: 2 years, 10 months
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: blindingleaf]
#23620995 - 09/07/16 07:21 AM (7 years, 4 months ago) |
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Thanks for the quick reply ya both on FP had same specs, other than how the filter itself was made
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mushpunx
Fungus Punk


Registered: 04/20/14
Posts: 13,394
Last seen: 11 days, 19 hours
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: spore-ty]
#23621194 - 09/07/16 08:48 AM (7 years, 4 months ago) |
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Are you the one building the 12 x 24? If so I sugguest building it just like the above photo, nice and simple like that. You can just attach a prefilter right to the side of your blower , easy peasy
https://www.shroomery.org/forums/showflat.php/Number/20807149/fpart/1/vc/1
Here's the little build log from when I built mine, if you search Evilmushroom666 has a good one amd Stro has an awesome one too
I wouldn't build a hood or walls if I were you.
Also, I sugguest using the good wood. You want your hood to last, so build it solid. I didnt have many woodworking skills so it was a challenging project for me but quite fun
As long as your filter and blower are properly matched, you should be solid !
--------------------
 Amateur Mycologists United AMU Q&A
Edited by mushpunx (09/07/16 08:51 AM)
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PutACapInHisAss
Stranger Than Fiction



Registered: 08/11/07
Posts: 252
Loc: Earth
Last seen: 6 years, 4 months
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: Supalemonhaze]
#23621670 - 09/07/16 11:26 AM (7 years, 4 months ago) |
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Quote:
Supalemonhaze said: The plenum being double the thickness of your filter is simply overkill and completely unnecessary.
It would be great to reduce the size of my plenum! Are you sure? I see commercial flow designs with smaller plenums but they seem to universally use baffling inside. I don't really know how to implement effective baffling (and I've searched for it a little). Also, other forum members have claimed that if the plenum is not large enough, the airspeed will not be uniform across the filter--higher at the bottom (if I remember correctly).
This would change my whole design but be welcome because it would reduce the footprint a lot. I suppose I could put my pre-filter in vertically rather than horizontally to reduce the size of this box. It is pretty big, I found a good deal on a Merv 16 house filter that is 16 x 25.
Quote:
mushpunx said: Are you the one building the 12 x 24?
I decided to go big, 2' x 4'. It will be a monster but it should make for quick and comfortable work where I can literally put everything I am going to use in the flow. It is going to be 3 modules that can be disassembled. They will be attached together using draw latches with a gasket material in between as suggested on a wood working forum. This way I can take the monster apart and move its pieces around.
I'm no expert but I have a little bit of construction experience. For future reference, there is nothing wrong with plywood if it is kept from getting wet. It is much cheaper than solid wood, lighter, and same thickness for thickness, it is *very* strong because of how the layers are sandwiched together. Virtually all homes not built on cement slabs have plywood flooring. It will stay strong for ages if dry. People put massive amounts of weight on plywood with furnishings, appliances, large numbers of bodies, and it holds up quite well for many years.
Coating with polyurethane is probably a great idea to keep it dry. Even a couple of coats of latex paint should keep moisture out well unless it is sitting in water. I'm not sure which is more cost effective.
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NumeroEno
I come from the land of lizards



Registered: 07/24/14
Posts: 9,652
Loc: Gamehendge
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: PutACapInHisAss]
#23621965 - 09/07/16 01:08 PM (7 years, 4 months ago) |
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I built a nice deep plenum on mine, so I don't know about whether a shallower one will do the same thing, but mine works nicely. I'm a woodworker and built mine to be both attractive and easy to maintain. With mine you can remove the filter just by taking off the front faceframe. I didn't use filter stops, just ripped down pieces of wood that I glued and screwed in place, and when you screw down the faceframe it compresses the foam around the edge of the filter and forms an airtight seal. Definitely don't silicone the filter in place. I used a marking gauge to lay out where the stops got attached. I built mine entirely out of solid pine craft boards finished with 2 coats of boiled linseed oil (decided not to use urethane as a personal preference) and it looks really nice, but it is very heavy. Plywood might be lighter but you'll have other issues with it unless you get the highest grade stuff, which is still pretty heavy. You will have to move it eventually. I recently moved out of a 2nd story apartment and carrying the hood down 2 flights of stairs and through the parking lot was brutal.
The one thing I did that I'm the happiest about is buying an overpowered blower and putting it on a speed controller. This is handy as fuck, since every house's electrical system is different. Say, for example, your hood is on the same circuit as your refrigerator. Every time the condenser kicks on it will pull current away from your motor, which could compromise your laminar flow. Now, when this happens in my place (I have an electric sterilizer and culture fridge plugged into the same circuit as my hood) I can just turn the speed controller up a little to compensate, and double check using the flame test.
IMO this is much easier than getting a blower that is only as powerful as it needs to be and keeping it on a dedicated circuit.
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Let it grow! Let it grow! Greatly yield! What shall we say, shall we call it by a name As well to count the angels dancing on a pin Water bright as the sky from which it came And the name is on the earth that takes it in DOG FOOD AGAR MY ELECTRIC INOCULATION LOOP
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PutACapInHisAss
Stranger Than Fiction



Registered: 08/11/07
Posts: 252
Loc: Earth
Last seen: 6 years, 4 months
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: NumeroEno]
#23622237 - 09/07/16 02:44 PM (7 years, 4 months ago) |
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Quote:
NumeroEno said: you'll have other issues with it unless you get the highest grade stuff, which is still pretty heavy.
A woodworker, I suppose you would know! Can you elaborate at all about the "other issues?"
Money is tight after I bought these crazy filters and giant blower. How do I identify the "highest grade" plywood? But, maybe such high grade stuff isn't cheaper than hard wood.
Edited by PutACapInHisAss (09/07/16 02:45 PM)
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mushpunx
Fungus Punk


Registered: 04/20/14
Posts: 13,394
Last seen: 11 days, 19 hours
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: PutACapInHisAss]
#23622265 - 09/07/16 02:51 PM (7 years, 4 months ago) |
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A 2 x 4? Will be awesome!!
If you know a little wood working it should be pretty easy for you. Whatever you use, just make sure its easy to clean!
--------------------
 Amateur Mycologists United AMU Q&A
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NumeroEno
I come from the land of lizards



Registered: 07/24/14
Posts: 9,652
Loc: Gamehendge
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: PutACapInHisAss]
#23622277 - 09/07/16 02:54 PM (7 years, 4 months ago) |
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The highest grade plywood will be 3/4" thick and have a nice smooth veneer. Other cheaper types of plywood have a shitty veneer which looks ugly, and tend to warp. Anything under 1/2" thick will lack the rigidity needed to build a solid cabinet. You can reinforce cheap plywood, but it's also a pain in the ass to cut. When you cut plywood you get "tear out" along the cut that can rip off the veneer or leave a jagged, messy cut. When I was designing mine I originally wanted to use MDF, which is what speaker cabinets are made out of, but it's really heavy so I went with the pine craft boards.
If you don't care about how the finished outside will look you can get cheaper plywood, but you won't be able to fasten butt joints together without a piece of wood in the corner of the joint to fasten both sides, and you'll need a 60 tooth finish blade to get nice clean cuts.
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Let it grow! Let it grow! Greatly yield! What shall we say, shall we call it by a name As well to count the angels dancing on a pin Water bright as the sky from which it came And the name is on the earth that takes it in DOG FOOD AGAR MY ELECTRIC INOCULATION LOOP
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PutACapInHisAss
Stranger Than Fiction



Registered: 08/11/07
Posts: 252
Loc: Earth
Last seen: 6 years, 4 months
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: NumeroEno]
#23622378 - 09/07/16 03:26 PM (7 years, 4 months ago) |
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Wow, all great info, worth starting this thread alone!
Quote:
NumeroEno said: you won't be able to fasten butt joints together without a piece of wood in the corner of the joint to fasten both sides
Exactly. I was gonna use 3/8" ply, wood glue, furring strips, and maybe some sealant. I already have one whole sheet and a partial lying around. This was my original plan but you are making me rethink it all now.
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NumeroEno
I come from the land of lizards



Registered: 07/24/14
Posts: 9,652
Loc: Gamehendge
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: PutACapInHisAss]
#23622416 - 09/07/16 03:36 PM (7 years, 4 months ago) |
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With mine I actually used a nail gun for everything, which wouldn't have worked with plywood. I just ran a bead of titebond along the joint, butted it up, and shot 1 1/2" 16 gauge finish nails into it. Nails and plywood don't play nice together. Even without a nail gun, you'll save some time nailing the craft board together over screwing plywood together. The only place I used screws in mine is where the faceframe attaches to the edge of the cabinet. I drilled slip holes in the faceframe and pilot holes into the cabinet so it would be easy to replace the filter (hopefully I won't have to for many years but still...)
So I guess my point is that you can save a little money by using plywood, but it will be more time consuming and possibly frustrating.
All the craft board I used for the whole project amounted to about the same cost (maybe a little less) as a sheet of good stain grade 3/4" plywood. Plus there was no wasted material and it took the linseed oil finish really nicely.
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Let it grow! Let it grow! Greatly yield! What shall we say, shall we call it by a name As well to count the angels dancing on a pin Water bright as the sky from which it came And the name is on the earth that takes it in DOG FOOD AGAR MY ELECTRIC INOCULATION LOOP
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PutACapInHisAss
Stranger Than Fiction



Registered: 08/11/07
Posts: 252
Loc: Earth
Last seen: 6 years, 4 months
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: PutACapInHisAss]
#23622634 - 09/07/16 04:33 PM (7 years, 4 months ago) |
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More awesome details, thanks!
I don't care how long it takes to put together so long as it goes together well enough to work properly and stay that way. Sometimes when you run low on money all you have left is time.
I don't mind spending the time to pre-drill my holes and the whole nine yards. If done well enough it should last for years and help to minimize what I now firmly believe is my biggest problem--dirty spawn!
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NumeroEno
I come from the land of lizards



Registered: 07/24/14
Posts: 9,652
Loc: Gamehendge
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: PutACapInHisAss]
#23622733 - 09/07/16 05:04 PM (7 years, 4 months ago) |
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Yeah for sure. I was broke as fuck, working at a shit job when I built my hood. I split the costs over 3 paychecks so it wasn't that big of a hit. If your 3/8" plywood isn't warped, and you're okay with doing nailer strips in the corners to hold it together, by all means go for it. Just remember that the nailers can't extend clear to the front of the cabinet -- your filter should be snug up against the edges and corners of the box, so you're gonna want to caulk the corners so you don't lose air out the sides. Don't have them go all the way to the back. They'll make nice stops for the back panel too.
3/8" is a little too slim to screw straight into IMO, even if you're pre drilling and using skinny trim screws, which you definitely should for a flowhood. The inner plies are made of shittier wood than the veneer, and the screw threads won't really bite in like they will with solid wood, which is why the nailers/furring strips/whatever are necessary. Remember as well, if you feel like it you can always build a better cabinet later on.
The biggest things to keep in mind with the cabinet are how sturdy it needs to be to withstand the vibrations of the motor, and hold together during moving. The motors are heavy and will make your hood really top-heavy. That and how airtight your design is. This is where I got impatient. I forgot to buy weather stripping when I bought everything for the cabinet, so I just sealed the back panel with duct tape. Some day I'll get the weather stripping, but for now the duct tape is doing the job. For the most part a bead of caulk along the joints on the inside will be plenty sufficient to make it airtight, but you can lose a lot of pressure out the back panel if you don't design it right.
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Let it grow! Let it grow! Greatly yield! What shall we say, shall we call it by a name As well to count the angels dancing on a pin Water bright as the sky from which it came And the name is on the earth that takes it in DOG FOOD AGAR MY ELECTRIC INOCULATION LOOP
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PutACapInHisAss
Stranger Than Fiction



Registered: 08/11/07
Posts: 252
Loc: Earth
Last seen: 6 years, 4 months
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: NumeroEno]
#23623735 - 09/07/16 09:09 PM (7 years, 4 months ago) |
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You did it again! I half want to leave you with the last word but thank you so much, there are a couple of gems I didn't even think of--especially that I can just make a better one later if need be!!!
Another question comes to mind also, have you ever used a product like PL Premium Polyurethane Construction Adhesive? It is a lot cheaper than wood glue in the caulking gun tubes.
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Supalemonhaze
Spore syringe hater.



Registered: 10/02/15
Posts: 6,725
Loc: 12" down Europe's butthole
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: PutACapInHisAss]
#23624631 - 09/08/16 03:29 AM (7 years, 4 months ago) |
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Quote:
PutACapInHisAss said:
Quote:
Supalemonhaze said: The plenum being double the thickness of your filter is simply overkill and completely unnecessary.
It would be great to reduce the size of my plenum! Are you sure? I see commercial flow designs with smaller plenums but they seem to universally use baffling inside. I don't really know how to implement effective baffling (and I've searched for it a little). Also, other forum members have claimed that if the plenum is not large enough, the airspeed will not be uniform across the filter--higher at the bottom (if I remember correctly).
The design is different than a commercial one. 6" should be the minimum for a 6" filter although slightly bigger is better. If you are going to be using heavy or thicker wood, it's going to be one heavy sumbitch.
Remember that the hood will have a total depth of the filter + the box. I didn't realize this until I drew it all up. With a 12" plenum, the box is going to be 18" deep. That plus the above average size of your filter and you're gonna have a monster on your hands.
I do have a question though, is your filter actually multiple filters?
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NumeroEno
I come from the land of lizards



Registered: 07/24/14
Posts: 9,652
Loc: Gamehendge
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Re: Please Tell, Laminar Flow Hood Build Mistakes, Errors...Little Details... [Re: PutACapInHisAss]
#23625065 - 09/08/16 08:29 AM (7 years, 4 months ago) |
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Quote:
PutACapInHisAss said: You did it again! I half want to leave you with the last word but thank you so much, there are a couple of gems I didn't even think of--especially that I can just make a better one later if need be!!!
Another question comes to mind also, have you ever used a product like PL Premium Polyurethane Construction Adhesive? It is a lot cheaper than wood glue in the caulking gun tubes.
It will work, but it expands a lot and it's a bitch to clean up. That stuff is more for using where you won't see it, like say you're doing a tile floor, you would use that glue in between the backer board and the subfloor before you screw the backer board down. For finish style woodworking projects, titebond is the only way to go.
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Let it grow! Let it grow! Greatly yield! What shall we say, shall we call it by a name As well to count the angels dancing on a pin Water bright as the sky from which it came And the name is on the earth that takes it in DOG FOOD AGAR MY ELECTRIC INOCULATION LOOP
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