New Video: Build Your Own Laminar Flow Hood for less than $100
Added 2023-03-22 00:11:46 +0000 UTCFull flow hood build write up (including links to items used) is here: https://www.patreon.com/posts/78502280
If anyone is looking for the Mycocoil (foot operated induction sterilizer) shown in the video it is here. And here's an example of the silicone tipped tongs that you can pressure cook and use for mixing grain spawn with substrate which is better than using your hands. If you want petri dishes that can be cleaned and reused, the glass ones are an option but often break in shipping, polypropylene ones are probably the better choice and they are less expensive.
Credit to: The Efficient Engineer (“Understanding Laminar and Turbulent Flow")
More about Reynolds number
Hope you enjoy the video version of the flow hood build.
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Links to all of my TEKs, Videos, Trip music, and frequently asked questions with answers can be found here: https://www.patreon.com/posts/22774475 (everything is made available for FREE, I do not use pay walls, support the work only if you feel like you've benefited from it and you are able to do so). People have told me my work has helped them overcome depression, addictions, PTSD, relationship issues, direction in life, and to have important, meaningful, sometimes life changing mystical experiences. I feel honored and blessed to play a small role in this. That is my reward.
Comments
Any idea how to cut a perfectly circular hole without having a hole saw?
WhispersFromTheVoid
2025-01-22 10:44:01 +0000 UTCYep, you can fill pretty big gaps with the silicone, hit it from both sides and when it dries its a perfect seal.
GordoTEK
2024-11-28 13:23:33 +0000 UTCNice idea. Yes it is normal for air to be entering and exiting the fan simultaneously, this happens when the pressure is hitting an equilibrium point. I did not notice any turbulance in front of the filter (work area) that resulted from this but your solution might offer some potential benefit.
GordoTEK
2024-11-28 13:22:14 +0000 UTCWelcome! You can send me a direct private message with your address: https://support.patreon.com/hc/en-us/articles/115002832026-How-do-I-message-a-creator
GordoTEK
2024-11-28 13:19:22 +0000 UTCI've seen pictures of professional flow hoods with a small gap between the filters, so I suspect that it should work. Example: https://res.cloudinary.com/dllgmrxds/image/upload/s--XqF5Uw_Z--/c_scale,w_1860/f_auto/q_auto/v1/main/redaktion/a2e89819271c6a54d6238f49d2f6ec42 She is even working right in the middle. However, she is also not elevating the dish on a rack or anything, so maybe she is not super concerned with contamination. It's not a stock photo, it's from a newspaper article about mycology. I am planning on building a flow hood with two filters side by side. I don't have a particle counter but I will test it by exposing a few dishes in different areas in front of the hood, as well as a control dish with the hood turned off.
Dolle
2024-09-17 09:58:47 +0000 UTCHas anyone tested the double filter iteration with a particle counter? I really want the space upgrade just concerned about the consequences of the gap and any slight offset in placement.
Alex Ward
2024-08-06 08:45:01 +0000 UTCCost about 100$ and has allowed me to explore the amazing hobby of mycology to a level I’d never imagined. Thank you Gordo for this video and easy to follow instructions and materials list. Gramps was an amateur mycologist who grew shittake and this would’ve really impressed him❤️🌈🙂.
Sur Worbz
2024-07-24 00:28:16 +0000 UTCI will be making one of those asap this is just what I need because I get tired of the sab so thanks for all the work you put into this for us
C Wayne
2024-06-25 15:59:59 +0000 UTCThank you! I built mine today, I did it for $114 all from Amazon. So that’s probably why I went over $100. But I’ll take it can’t wait to put it to use. I expect this to be a game changer, especially when it come to agar work.
Brent
2024-06-09 20:02:18 +0000 UTCI just screwed it in place and filled the gap with LEXEL it worked perfectly
Dan
2024-06-02 23:02:53 +0000 UTCI know this is old but I plan to use Gorilla Tape if I have this issue. What did you end up doing?
Tiffany Logan
2024-06-01 14:27:47 +0000 UTCHey Gordo, just joined, great content!! how do I send you my address for the spore print?
kyle scrimsher
2024-04-04 22:28:17 +0000 UTCA possible addition to this build: Air Input Cone We have some hard-earned laminar flow right in front of the filter that we do not want to disturb. But on the right side of the box, at the mouth of the fan, we have a tornado happening! One may presume since the fan is pulling air into the box that it would all be flowing in, but it's got a lot of air coming in and out of the fan tube, making for a lot of churning air that's too close to our laminar flow for my tastes. The solution for me was a tube made of poster board, arbitrarily measuring 10 inches. Rather than have the tube the same diameter, I made it taper from 8 inches to 4 inches over the span of the 10 inch height. This makes a nice gentle pull of air into the 4 inch opening, and the 8 inch opening is just taped to the box. If you picture a cone with an 8 inch base that's 20 inches tall, we will be constructing the bottom half of that cone. So loop a string so it measures sqrt(4^2+21^2) = 21.4 inches. Fix one end of the string and put a pencil in the other end and make an arc on the poster board of at least 75 degrees. Now, with the same fixed point, shorten the loop and make another arc with a 20.4 string (this extra inch will be folded out as tabs to tape to the side of the box). Finally shorten the string so it measures sqrt(2^2+10^2) = 10.2 inches and make another arc. Cut along the 10.2 and 21.4 inch arcs, then every inch or so, cut from the 21.4 to the 20.4 arc to make your tabs. Roll it up so the big end fits over the fan input, then tape it to the box. Now you have a nice gentle air input that's removed some distance from the laminar flow area.
DRS
2024-02-28 17:36:06 +0000 UTCMy first attempt at building this flood and I used the 8 inch whole saw but the fan does not fit snuggly. There’s almost a 1/4 inch gap and that seems like too much to fill with silicone. Any suggestions?
Dan
2024-02-26 20:18:44 +0000 UTCGordo answered this somewhere else that I read. I believe he said because it's not running very many hours, the filter lasts a lifetime. In that same paragraph, he says to turn it on before you remove the towel and let it run for 15 minutes to clear the room of some of the particles.
DRS
2024-01-22 22:34:42 +0000 UTCI did see that, but you don't really have a bigger work area; you have two of the same size work areas because of the split in the middle. Anyway, thanks for the reply. I'll just work with it.
Paul D Hierholzer
2023-12-09 00:11:07 +0000 UTCNo, sadly, the MERV-13 filters will not work for this project. You can read more about MERV ratings here: https://www.epa.gov/indoor-air-quality-iaq/what-merv-rating But bottom line is that you need a true HEPA filter. You CAN indeed use two of the recommended filters side by side, a bunch of people have already done that and reported success (there is even a picture of one in the written version of the TEK: https://www.patreon.com/posts/78502280 )
GordoTEK
2023-12-08 22:52:10 +0000 UTCIts not going to make any difference, air pressure level will be the same.
GordoTEK
2023-12-08 22:48:52 +0000 UTCI have never used the 6, but other people have told me that it worked for them, and I have no reason to doubt that it would work with the recommended filter.
GordoTEK
2023-12-08 22:48:15 +0000 UTCYea, I have not used that carbon filters for anything personally. Its probably best to save them for some other project. In theory you might be able to put it over the fan intake or behind the HEPA filter but I think its best to just not use it for this project. It could interfere with the airflow.
GordoTEK
2023-12-08 22:47:45 +0000 UTCYea, what Mitchel said, but also want to correct you, I recommend and used the 8" raxial fan, BUT some people have told me they used the 6" one and it still worked, so I think its fine for the recommended filter, but may not be adequate for other filters. Don't over think it, but yes, the fan must generate enough pressure inside the box to push air through the filter, this is not a problem for the given fan. The better the box is sealed up, the higher the pressure is going to be for a given fan speed. It is also normal for air to be coming OUT of the fan as well as IN through the fan, the excess pressure causes a little backflow, this is normal, and having the fan on the side will ensure this backflow doesn't affect your work area.
GordoTEK
2023-12-08 22:46:18 +0000 UTCYea I have never used it, and I agree with Cooper. Its basically only good as an air freshener.
GordoTEK
2023-12-08 22:40:46 +0000 UTCNice, thanks for sharing. I should have done a true "control" like you did, for the video, but I don't like growing mold in my house, haha!
GordoTEK
2023-12-08 22:38:49 +0000 UTCI built this and it came out great. Thanks. The working space is a bit small, so I bought a 200 quart container with lid to increase work area. Problem: can't find a HEPA grade filter in 14 x 30 size, but I found this one: https://www.amazon.com/dp/B00TUDHSL2?psc=1&ref=ppx_yo2ov_dt_b_product_details Questions: 1)Do you think it's good enough? 2)Do you think the 8 inch raxial fan is strong enough? Could I use 2--one on each side?
Paul D Hierholzer
2023-12-04 20:53:23 +0000 UTCand he said that will work
Bill Murphy
2023-11-18 04:42:06 +0000 UTC@greenhead I already asked Gordo about using the 6" infinity fan
Bill Murphy
2023-11-18 04:40:38 +0000 UTCThanks! I got a philips filter. Is the direction which side I place facing outside important or is the air flow equal no matter how I turn the filter?
Pascal D‘Agate
2023-10-25 22:39:00 +0000 UTCCan I use my 6 in infinity fan instead of buying the 8 in ?
greenhead
2023-10-05 04:53:07 +0000 UTCSo were you successful? I think you’re thinking in the wrong terminology. All that’s important here is cfm, your filter will have a chart showing how airflow is affected by different cfm rates you would need to ask manufacturer for that. It is not necessary as tons of people have done this with success, even using two filters which is significantly more area than you are using. I plan on using a 18x18 filter with the same fan he suggested and expect no issues.
Mitchel Wangler
2023-08-30 20:11:48 +0000 UTCNo need, prefilter is not necessary; as he says in the video feel free to use that for carbon agar.
Mitchel Wangler
2023-08-30 20:08:28 +0000 UTCHey Gordo, I’m building your flow hood and I ordered the filter you recommended and it came with a pre filter. How and where should I place it. I’m thinking of glueing it directly to the hepa filter with double stick tape. Please advise. 🙏 Thank You
Ronald James
2023-08-21 22:43:50 +0000 UTCHi Gordo, I'm trying to gather all I need to do this and I've already got the h13 filter (a large one, about 30x40cm or 1.29sqft from Fellowes) and the box, now I think the inline fan TT125 280m3/h I have won't do for the filter size (it would require 220m3/h at 100cfm, but initial pressure drop should be considered). my concern is basically that i don't understand fan pressure requirements, because it seems the AC infinity 6" raxial model that you recommended (and used succesfully!) only produces 7.65mmH20 or 75Pa, and the TT125 charts the maximum initial pressure drop to keep a minimum of 220m3/h airflow at no more than 60Pa of resistance from the filter pressure drop. the issue is I don't know the static pressure of the Fellowes filter, but it seems regular h13 filters have 25mmH20 or 250Pa resistance, which would be way too high for the fans. i've looked for mini pleat filters (here: https://ventmarket.eu/en/product/hepa-filter-h13-h14) and they boast a low pressure drop of 120Pa. Also I'd already had a look at FreshCap's guide to DIY flowhood and he used a more powerful centrifugal fan, which if I understand correctly provides higher pressure and not just high cfm (granted, he used a deep pleat filter which does need higher pressure, but still). The only thing that makes sense to me, since your design works, is if these filters have a resistance way below 250Pa, even below 75Pa, so that the box is pressurised only if fan pressure is higher than that of the filter. Or maybe I got it backwards and the fan must have high enough airflow (surface sqft*100ft/min) but the pressure must not exceed the resistance of the filter or else it breaks. I'm just at a loss and would like to avoid buying unnecessarily costly stfuff, nor lower-performing cheaper stuff that ultimately is not good enough and needs replacement. Would you mind weighing in on this please? In the mean time I'll fit the filter on the box anyway and I'll test if the current fan is up to the task, just to allow the possibility to be surprised positively. Cheers
MR nemo
2023-08-08 10:56:24 +0000 UTCOverkill. If you want to prefilter the air, use something over the fans intake
Cooper
2023-06-01 20:56:35 +0000 UTCDo you need to use the included carbon filter that comes with the hepa filter when building the laminar flow box ? I was thinking of adhering the carbon filter part on the inside of the box and then adhering ( with silicon) the hepa part on the outside of the box . Overkill ?
John Ledington
2023-06-01 17:12:58 +0000 UTCI did my own flow hood using this guide, but using different filter. I also did agar test. 2 plates of agar for 5 minutes in front of flow hood and one plate with flow hood turned off. It was 4 days ago. First two plates are still clear! Third contains nice mold mycelium and one bacterial colony. So flow hood seems to be working fine ;) I will consider experiment as successful in 3-4 days :P
Pawel
2023-05-18 01:19:33 +0000 UTCI fumbled around with a few different glues in cluding Loctite Superglue which like the others had a hard time because of the porous nature of the filter frame. I got it to work but I also used silicone caulking on the front and back edge of the seam itself to give the bond more strength. I would recommend skipping superglue - just use the silicone caulking that is being used for all the seams and the top cover of the flow hood. Another reason to avoid superglue: The particle meter I used to test the filter also tests for volatile organic compounds (gnarly chemicals) and even a week after the superglue had dried, the air coming through it showed high / unhealthy levels of VOC's when I placed the testing device in front of the glue seam. So best not to use any toxic glues! The filter I sent the link to has a very thin "frame" around it and I did not remove any of the frame material when gluing the two filters together. This thinness of the frame is the main reason I chose this filter over others of similar size that had much thicker frames.
Tree of LIfe
2023-05-10 06:04:46 +0000 UTCThank you so much for responding, I really appreciate it! It's great to hear that it's been working. If I may also ask, how did you glue the 2 filters together? Do I need to take one of the sides off both of them?
Majora
2023-05-10 04:57:05 +0000 UTCThe agar cup test was successful. I also tested the outflow with a particle meter (though not as fancy a device as Gordo's) and it showed zero particles making it through the filter. However I HAVE had some instances of contamination in agar cups which I did mycelium work with in front of the flow hood. But I think it was due to bad technique on my part, not the flow hood. Meaning not being mindful enough of keeping a clear path for the flow from the filter to the agar cups I am directly working with, working too far in front of the filter, having the air flow too weak or too strong, etc. Plus there is the fact that the spare room I have the flow hood in has been used in the past for food fermentation projects like jun, kombucha and kimchi. So there may be errant bacteria and yeast floating around just waiting for the opportunity to reach some new substrate. By all means feel free to copy the design - I hope it works well for you! I'm just happy to share whatever may be of benefit to others in our hobby.
Tree of LIfe
2023-05-10 04:14:24 +0000 UTCThe Phillips filter is a little bigger. I'm sure there are others out there but no I have not personally tested those yet. If you find one you want me to test, I will certainly consider it.
GordoTEK
2023-05-10 03:02:44 +0000 UTCSorry for replying to a comment that's a month old, but I was curious how the open agar cup test went. I'd like to copy your design if that's okay, but I wanted to know if it worked or not.
Majora
2023-05-09 23:40:56 +0000 UTCDo you mean that makes no difference whether coir substrate is spawned in filtered air or not? I used straw the first time in front of the flow hood. It was a messy business and threw a lot of particles into the filter. But those trays flushed with no contamination for many weeks until they pooped out. If I can do it on a table and not dirty my filter with no difference, would love to know. Thanks Gordo!
John Maret
2023-05-05 18:56:36 +0000 UTCLooking through the linked hepa filters all about a 14”x12” size. I saw that you can do two with the same fan, just treat as two separate spaces, but I was wondering if you’d come across reliable larger filters to allow for a larger working space?
Andrea Eickelmann
2023-05-04 16:49:23 +0000 UTCThank you- I will be making this soon.
Riverchick
2023-05-03 16:38:57 +0000 UTCHow do we know when to change the filter?
Vincent Phillips
2023-04-05 13:44:31 +0000 UTCNice job! Yea the fan is probably a bit over the top but the price was right and I like it. Could probably get away with a smaller one. My thinking was that as the filter aged, it might require higher power levels to get the same flow rate (due to the filter accumulating debris).
GordoTEK
2023-04-05 01:46:13 +0000 UTCHaha, you will run in to all sorts of people out there, I don't know how you could watch this vid though and conclude the design doesn't work! I tested with sophisticated particle counter, with flame test, and with actual multiple agar tests and complete spores to harvest test too. Zero contamination.
GordoTEK
2023-04-05 01:44:42 +0000 UTCBelieve it or not, the actual spawning of the substrate doesn't really need to be done in front of a flow hood although its a nice plus if you can do it that way. The big commercial mushroom growers pretty much NEVER spawn in HEPA filtered air, its just not practical and not necessary. The same pretty much applies to home growing too though. I did it that way in the vid just to show its possible. If you look at my bulk grow vid for example, spawning was done in open air, and you can see this made no difference, with flush after flush and massive total yields: https://www.patreon.com/posts/29675383 Straw substrates are more prone to contamination though, definitely a plus to do those in front of a flow hood.
GordoTEK
2023-04-05 01:42:11 +0000 UTCYes that's exactly right. Sorry if I glossed over that too fast in this laminar flow hood video, I think I sped that part up probably too much but the vid wasn't intended to be a tutorial on agar work. Yes I have a separate vid that is actually a tutorial on agar work: https://www.patreon.com/posts/56209839
GordoTEK
2023-04-05 01:37:12 +0000 UTCI did not use the pre-filter at all, but I'm not opposed to the idea, I doubt it would affect the fan setting very much at all, and the fan is actually strong enough to produce proper flow from TWO of the actual HEPA filters simultaneously based on reports I've received from people who have tried it.
GordoTEK
2023-04-05 01:34:52 +0000 UTCHaha, perfect! Well I really just put Bob in there because a bunch of people have called me the Bob Ross of Psychedelics, I think mostly just because they think our voices are similar. The crazy hair hat thing is what I sometimes use as either a disguise or a hair net for clean procedure (take your pick).
GordoTEK
2023-04-05 01:31:20 +0000 UTCI used the same fan that Gordo cites in his write up of the build. Here's the link to his tek: https://www.patreon.com/posts/78502280 The flow hood was completed just last night and in terms of the two filters, it is nice to have the extra horizontal working space. The laminar flow all across the width of the 20-inch cooling rack was smooth and strong. So far so good, as the saying goes..
Tree of LIfe
2023-04-04 04:22:59 +0000 UTCAwesome job, can I ask what fan you went with, any of you how have built gordo's? Wish I could find the one in the original video... Also, hows the 2 filters working for you?
OKayBuds
2023-04-03 21:56:01 +0000 UTCHere is a DIY flow hood using two side-by-side 11x13 filters that have been glued together. I like the larger work area. 20-inch wide cooling rack is resting on pieces of 1"x2" wood so items can be placed within the sweet spot of the laminar flow. A 5-minute open agar cup test was done and am awaiting results. <img src="https://i.imgur.com/b7vp7q3.jpg" title="source: imgur.com"> Here is the tub that was used as the host: <img src="https://i.imgur.com/DBjJbPx.jpg" title="source: imgur.com"> This made for easy cutting of the plastic to make room for the filters: <img src="https://i.imgur.com/zAQnyjk.jpg" title="source: imgur.com">
Tree of LIfe
2023-04-03 17:24:46 +0000 UTCThanks so much for the genius idea of using a variable speed blower! I made mine out of wood and a cheaper 4" fan with a rating of 195 CFM.
Jessica Uy
2023-04-01 16:50:19 +0000 UTCJust built this device and have done the 5 inch off filter face open agar plate for 5 minutes test. I gotta tell ya, when posting pics of this, some folks are REALLY not receptive. Doesn’t matter to me though. If my plate has no growth at 5, then 10, then 15 days out I’m gonna call it good.
PhreakFakt0r
2023-03-31 16:12:23 +0000 UTCThis is really cool, I love the idea of hacking my own flow hood together. Unfortunately it looks a little too small to comfortably make a pan of TTBVI inside the flow. I would love to see a larger version, ideally about 3' wide.
Benjamin West
2023-03-25 14:58:09 +0000 UTCHey John, You should check out Gordo's video on making agar plates. He explained everything there. If you go to the FAQs and scroll you'll find it quickly. After sterilizing the inoculation loop by getting it red hot, you dip it into the agar on your agar plate. This cools the inoculation loop and gets some agar stuck to the loop which aids in collecting the spores to smear in the plate. Definitely watch that video! It's really good and explains everything in detail.
Do Boy
2023-03-23 23:28:34 +0000 UTCHi Gordo, nice project video very clearly presented. Also love the extra mile you go explaining the physics of ‘laminar’ flow. One question though, when you sterilize your inoculation loop so it’s glowing hot how do the spores not burn to a crisp when rubbing onto your foil picking them up to smear in the agar plate? Cheers John
Johnny Flash
2023-03-23 23:03:47 +0000 UTCThank you Gordo, for sharing. Did you try to incorporate HEPA with prefillter in this build? If I silicone them together, how much would this affect flow with the same fan you using?
adam n
2023-03-23 03:26:09 +0000 UTCGordo. You are the best! Haven't laughed this hard in a while.
Sadie Cat
2023-03-22 17:06:59 +0000 UTCOnly thing I couldn't figure out was Bob in a beret, I couldn't remember ever seeing that . . . but then, I found this: https://shop.asomf.org/bob-ross-beret-lets-get-crazy-sticker/
Sadie Cat
2023-03-22 17:05:43 +0000 UTCI especially love the Bob Ross impersonation! Wig needs a perm though.
Sadie Cat
2023-03-22 16:56:53 +0000 UTCOnly you can come up with stuff like this.... Excellent work
jrivera1
2023-03-22 15:18:14 +0000 UTCLove it man. I wish I would have done this myself before spending way too much on my flow hood. I love mine, but the money could have been better spent ;)
Gary DeSanti
2023-03-22 02:37:54 +0000 UTCI got this 4x2 FFU from Aliexpress and works amazing. No contams at all so far and plenty of working space. Was just over 500 CAD with shipping and would recommend it. I did have to use a construction adhesive to seal the filter to the unit which was very fast and easy. Good price and lots of extra power as I use it on the medium setting (out of 3) with a 2500 prefilter (which is a bit overkill for a prefilter). Downside is the ship took about 2 months and is the lions share of the price. https://a.aliexpress.com/_m0xtEZk I also have a Thermohelix version of the induction sterilizer. Those are great units. I have both (FFU and induction) on a smart powerbar so just turn them both on remotely 10 mins before doing work and off together. I don't find the foot pedal necessary as I just leave it on and it only heats up when a metal instrument is placed inside the coil perched on a stand. Best wishes :)
Ced Kar
2023-03-22 01:58:47 +0000 UTCYou make it look so easy. Wish mine went together that quickly. 🙄
Sadie Cat
2023-03-22 01:45:35 +0000 UTCBravo! Nice job!
Sadie Cat
2023-03-22 01:43:01 +0000 UTCThank you. I will start building tomorrow 😁😁
Laryssa Fenn
2023-03-22 00:32:44 +0000 UTCGreat video. Thanks for the shoutout.
2bags
2023-03-22 00:23:31 +0000 UTCGood to hear your voice again
L
2023-03-22 00:14:58 +0000 UTCThank you.
Jason
2023-03-22 00:13:25 +0000 UTC
