How To Design and Build A Laminar Flow Hood: Part 1 - Design

In this video, I show you the process for designing a laminar flow hood- or more specifically, how to properly choose a filter / fan combination that works.
Part 2: • How To Design And Buil...
Step 1: Choose the right type of filter, and the right size
Step 2: Specify a fan that is powerful enough for your filter
Step 3: Build a sturdy box to hold it all together
Get Flow Hood Plans Here: freshcap.link/diy-hood-plans
Check out our new growing blog: learn.freshcap.com/growing/
Learn About Functional Mushrooms: learn.freshcap.com/mushrooms/
🍄☕🍄☕🍄☕🍄☕🍄☕🍄☕🍄☕🍄☕🍄☕
Try our best selling functional mushroom blend for energy, immunity and cognition.
👉 freshcap.com
Use code TRYMUSH10 for 10% off your first order!
🍄☕🍄☕🍄☕🍄☕🍄☕🍄☕🍄☕🍄☕🍄☕

[@gordotek]

This is a nice vid although he makes some important mistakes: He says you need a 99.99% (0.3 micron) efficiency filter, this is ULPA not HEPA, it is a mistake to use ULPA filters because they clog much faster than HEPA, they require more powerful (and more expensive) fans, and the additional filtration level is totally unnecessary. The primary thing you are trying to filter out is competing spores like trichoderma, if you do the research you will see that all of the common contam spores are well over 1 micron in size. Also the old school traditional design is heavy, not portable, and expensive. He also states that you need huge filters to get laminar flow - this is not correct. If anyone is interested in a light weight, VERY inexpensive, portable design, see my vid "Build Your Own Laminar Flow Hood for less than $100 (really WORKS!)". Wishing you the best everyone.

[@MissBlackMetal]

Thank you for sharing your own video, because after I saw he chose a $200+ , fan for his hood, I immediately wanted to know how much everything cost him, considering I've seen laminar hoods start at $300... Seems like a LOT of extra work to not save much (if any) money which seems silly unless you need the customization. But my interest is saving money, so I'll be watching your video now! 😊

[@buttninjaflex]

​@@MissBlackMetalwhere are you finding laminar hoods starting at $300?

[@SimonRisspy]

Hi Gordotek, big follower of you! I do have a question to your comment though: As far as i know the filter classifications are as follow (0.1-0.3 microns): H13: 99,95 %, True HEPA: 99,97 % H14: 99,995 % U15: 99,9995 % (ULPA) why not choose an H14 if you run a pre-filter, which would prevent clogging up the big H14 too fast? I know this build is definately more expensive, but i wanted a little bigger workspace and found a 24x24 Inch quite inexpensiveley over here in Germany.. of course the fan needs to be quite powerful (therefore more expensive) for my build but I guess that's what I am going with.. Would love to see a video of you if you by chance decided to build another model (maybe this time a reasonable-priced-high-end laminar flow hood.. Thanks for sharing your knowledge! Support @gordotek guys, really smart guy! Cheers

[@followingleader4733]

Tony, from freshcap. I loved the educational value of this video as I recently have an interest in things such as hvac, mycology, and welding. It was great the way you explained the pressure drop, filtration percentages, fan curbs, and filter size. Back in school diagram boards like the one you drew went over my head. Now that its years later I'm finding that things such as this aren't so difficult to grasp. So thank you sir, please do continue!

[@FreshCapMushrooms]

So glad you liked it! It was kind of confusing when I first learned it so I wanted to try and lay it out in an understandable way. Building a flow hood really changes the game for growing mushrooms, so it's definitely worth doing! Of course, you could always just buy one, but building your own is a little more fun ;)

[@13ninjamoose]

I followed your plans and now I have a beast of a lab. Thank you for your instruction.

[@ilikedogs870]

Does this specific FH prevent you from getting contams? You feel like it was worth it?

[@jada90]

Great video. I've read several writeups for making these, but the video format just makes everything so much better. The fan curve graph is great.

[@tech1media842]

I followed your method step by step and built me the exact same one. I am so happy with it, I wish I can post video or picture of it. thank you for all your help.

[@sweetdragon36067]

Another very good, to the point with no fluff video and explaining exactly what I need. Thanks.

[@enzolong9085]

these 2 videos are so good, thanks alot Tony! saving at least half a grand by making my own now.... and for a bigger size!

[@ElfinNutria]

Timing couldn't be more perfect, thank you Tony!

[@FreshCapMushrooms]

Awesome! The build video is coming soon!

[@thegreenroomorganic]

You sir are a legend. So much love and gratitude 🙏🏻

[@treyott9638]

Fantastically detailed spec video. Exactly what i needed! Great info explained simply.

[@MrPipp007]

Great stuff! Love your work! Very inspiring!

[@bounceurabdelaziz4973]

Thank you Tony for all your sharing,Bonne Continuation.

[@Filekv5]

Yes, I was waiting for this. Awesome

[@christian9506]

This was really really helpful and easy to understand. Thank you for sharing this information.

[@Golden_Teacher]

Probably the clearest example yet of how to choose the right fan...

[@nikolanovakovic4150]

This is fantastic information by god, i mean it's just fantastic knowing that this kind of knowledge is available to anyone in the world !

[@jdolby513]

Finished building mine last night - thanks for this awesome guide!!

[@ilikedogs870]

Have you used it? Is it reliable and effect? What are your success rates?

[@shaunposton5547]

Perfect! This is exactly what I’ve been looking for! Thanks man!

[@FreshCapMushrooms]

Happy to help!!

[@DMT4Dinner]

Much needed content, bro. Thank you

[@isaac7297]

took a min to get what he was talking about but was worth it in the end, thanks bro!!

[@MorrisBlaster]

Tony you make great vids man. Thank you!

[@chrisfasciotti3089]

Wow! So extremely well explained, fantastic brotha! Your killin the game! Much ❤❤😎

[@yandigilov469]

Tony, you are the man.

[@YouOriginal]

Can you please put links in the description so we can buy or at least see codes of what we need?

[@activeenglishlecreusot9628]

Clear and to the point. Good advice as always.

[@FreshCapMushrooms]

Thanks! Stay tuned for part 2! :)

[@mysalam]

Hey man, much appreciated for all you are doing...

[@FreshCapMushrooms]

Thanks for watching! Glad it is helpful :)

[@nubletten]

Very much apreciate the cover of the calculation! I can convert this freedom volumetric calculation to actual metric now ;)

[@MyceliaSteph]

great vid!

[@foxhill1212]

Thank you for this and all your videos!!! This especially!

[@FreshCapMushrooms]

Glad you liked it!

[@righteousmonarch9499]

Now this video im loving right here 😍 🙌

[@ashsherman]

How long it take u

[@ggezpro7163]

Thanks for Sharing. You helped me so much. I spared no expense and copied exactly

[@victorandrovichjr.4384]

Please tell me where to buy that exact filter?

[@niranjankanamaluru101]

Thanks so much Tony...

[@FreshCapMushrooms]

You are very welcome! Thank YOU for watching :)

[@adamcenturione8631]

Wow Thanks Tony!

[@mycoalliance1909]

This is awesome!!!!

[@FreshCapMushrooms]

Glad you like it :) thanks for watching!

[@SmartAirFilters]

Great video Tony and FreshCap. You certainly know your HEPA filters! Looks like you've used an image of a Smart Air HEPA filter at 02:32 when you're comparing thin vs. thick HEPAs. Awesome! Just to clarify - you're right many filters from Home Depot are lower grad (e.g. MERV7 or MERV9), but all our filters are HEPAs that get 99.9% of particles. But you're spot on - thicker HEPAs should be used when laminar flow is needed. More importantly, the HEPAs should have a honeycomb section to straighten out the flow once it's passed through the HEPA filter. You can see the aluminium (silver) honeycomb in the filter you bought at 03:48. That's vitally important. We're big advocates of DIY air purifiers (and laminar flow hoods!), thanks for using our filter in your description!

[@FreshCapMushrooms]

Thanks for clarifying! I guess the important distinction is the thickness and the honeycomb section to help with the laminar flow. If laminar flow isn't required, the thinner filters can work just as well for scrubbing the air.

[@slysly2338]

Hello, do you still sell these filters? If so can you provide a link?

[@x1Conan3Spartan0x]

Your consistent. I need to work on my eye contact because I didn't get distracted not once.

[@loudlikelove5016]

thanks!!! very clear

[@R-Rpt]

I watched these videos in the first place, you tell them very complicated, it is not that difficult. 1- The filter you choose should be Hepa H14 %99.99 and it should support laminar flow, 2- Find out the initial pressure and final pressure drop of the hepa filter. For example start 140pa - final pressure 450pa - maximum 600pa pa = pascal 3- How many m3 of air passes your hepa filter per hour, for example 300m3 4- When choosing a fan, you will look at the table and there are pressure pascal values, starting 140pa, but this will increase up to 450pa when the filter is used. 5- You choose the fan according to the final pressure drop, that is, you will choose the fan that reaches a value close to 300m3 at 450pa end pressure. 6- You will get 1 dimmer speed controller for the fan. With this speed controller, you will slow down the fan speed and use the air flow you need at the initial 140pa pressure. As the filter becomes clogged, you will increase the fan speed and have the air flow you need. My experiences: the air flow out of the filter is 300m3 / h, we will not release an air flow at this speed, when I turn on the fan, I reduce the fan speed and I watch a lighter or my gas stove burning stably in the laminar flow. I am not measuring how many m3 of passing air is per hour. I totally make an eye decision and a slight current is enough. I have done liquid culture, tissue transfer, agar to spore print, spore syringe, spore print and zero contamination! It definitely works, do not worry about how to do it, refer to the items I have described above. I have read a lot of articles and there is indeed a lot of confusion. Don't waste any time, the basic logic is like this. footnote: Maximum air flow to a hepa filter of 300m3 / h should not exceed 360m3 / h, laminator flow is disrupted, prefer slow operation instead of fast, while you are working, the medium is not circulating, if there is circulating, you can increase the amount of current.

[@blakebeaton8410]

So you don't need ~100fpm on the other side of the filter? I'm measuring 21-24 fpm. Good enough?

[@R-Rpt]

@@blakebeaton8410 Our measurement units and your units are different, but if you do it with the logic I said, you probably won't have any problems, use an adjustable dimmer. With the help of a lighter or candle you can tell if the flow is laminar or not, you don't have to use them every time. Too much flow rather than less creates turbulence.

[@Omnipotent645]

Im curious about what kind of rate of m³/h your h14 has since you took 300m³/h as an example and all h14s I can find are at 1400 m³/h. Is this apropriate for a h14? Im asking because that would determine how much the fan will cost and how much energy it needs. TIA

[@R-Rpt]

@@Omnipotent645 I just took the h14 filter and looked at the "pascal" value and bought a powerful fan to match the last projection "pascal" value when the filter was completely clogged. As the fan gets dirty, its pores are clogged, so the pressure value is constantly increasing. Since the fan I bought will normally be very powerful, I connected a dimmer to it, I make the dimmer setting completely blind. I see that the flame of my alcohol stove is laminar. The flame does not fluctuate. my h14 filter dimensions are 30cm x 60cm, if the dimensions of the h14 filter you are looking at are large, the m3 value will naturally be high. there is no problem with that. As for energy, I assume that you will not spend 8 hours a day at the beginning of this, the energy calculation is not very important, if you want to calculate how much electricity it consumes, you can calculate the power used by the fan. My h14 filter

[@mjhklop8999]

Thanks for the invaluable info

[@JustRobPlays]

Super good video.

[@brain_storm7261]

Great job.

[@FreshCapMushrooms]

Thanks for watching!

[@johndice9174]

Thanks for the vids

[@Boomshankarim]

Hey Tony, I’ve been searching for a proper blower fan for my 24”x24” filter….but getting these fan curves from the manufacturers is near impossible and finding a proper blower fan that fits your pressure criteria is also near impossible. Edit: Reading the comments below, I think I found my answer, gonna put a dimmer on my powerful blower and gage the laminar flow of the air coming out of my filter using a flame test, the flame should not flicker. Also the dimmer allows to increase the power of your blower as the filter ages and gets clogged with more dust particles. Kudos for all the help.

[@lautarogatti]

Hey, this looks like a great idea, can you help me understand how to do this technique? im also building a 24 by 24 and using the TDU2 seems a little bit overkill, but maybe i can dimm it down like you are suggesting, did it work for you?

[@codyquinn4954]

@@lautarogatti cant use a speed controller with a tdu2

[@nk-yy3ki]

Thanks for the concise explanation regarding how you figure out the fan size - awesome job. In fact, thank you for all your vids. On a side note, i couldnt help but think that at 8.10 you remind me of Sheldon but with facial hair - I hope you go on to become as wealthy as he is😁😁😁

[@NFTMule]

i was just thinkinh about building one of these today as i was trying to do agar work in my SAB and it kept fogging up and boom your video popped up. thanks!

[@FreshCapMushrooms]

Awesome! Ya a flow hood changes everything- I'll have the build video up hopefully by tonight.... along with a link to all the build plans with dimensions ect.

[@jmichel70]

Thanks

[@barnagorfol1]

Hey Tony! I am a very big fan of yours 'cause you are a big motivator to me to cultivate mushrooms. I started to cultivate mushrooms like almost a year ago. I started with a big glovebox, but it is not enough now. Keep going! My question is that would it be enough to buy a 99.95% filter for the laminar flowhood, or the 99.99% is neccecary? Thanks in advance!

[@nikolanovakovic4150]

this is some good content

[@jaimedelgado7529]

thank you. I very appreciate you making this video. at the same time so much great info and you left out the more important. how much will this endeavour set me back ?

[@PeterSedesse]

This really would have been a good place for affiliate links. Maybe 3, one of each size filter and then a link to the actual filter and a fan that would work well with that size filter.

[@ethanlng1147]

Great video! You're great at explaining stuf! Is it bad if the fan will be stronger then what I need for my filter?

[@robcroyle]

Love the channel! Found you last night and absolutely love the videos! You sir are a hero and genius! Plan on building my own next year! Video suggestion; how to make a spore print/spore seringe and how to properly store them.

[@FreshCapMushrooms]

thanks for the props! I hope to continue providing valuable content for all of you :)

[@kereyc5751]

One uneducated word of advice I have about fans is using either a squirrel cage fan OR my favorite type of fan is an inline blower fan. You can buy a fan that you know pushes more air than you need and you can just buy a variable speed knob that the fan plugs into and you can adjust the thrust of the fan by using the dial. I feel like thats much easier than doing a bunch of math and trying to get the EXACT fan and CFM you need.

[@mayhemgaming154]

Box fan window cardboard box and painters tape and a furnace filter. Done

[@stevenkirincich2397]

Great video. I was planning on using a 24x24x5.8 filter. With a maximum filter flow capacity of 550 CFM, there are no affordable blower options capable of delivering this lower flow while at 1.3 inches of static pressure.The 24x24x11.5 filter would be compatible with the blower described in the video. Learning!

[@FreshCapMushrooms]

Thanks! Glad you are finding it helpful :)

[@lautarogatti]

did you end up using the TDT8 blower? or the TDU2 ?

[@robertmclean9737]

Visor on the Front of your box to force air down as well as Horizontally. Cheers

[@pollopollo3531]

Very timely video!

[@FreshCapMushrooms]

Good stuff! Hopefully it helps! I am coming out with the "build" video and build plans very soon. Hopefully today :)

[@pollopollo3531]

@@FreshCapMushrooms my buddy is building me one with specs from your website. Your explanation of equations was a great help. I think this series of videos will be a great visual guide to what's on your site.

[@FreshCapMushrooms]

Awesome, ya I am going to be releasing the build plans for this one with dimensions and everything, I can definitely send you the plans I made a model in sketch up, on the next video there will be a link to get the exact plans.

[@pollopollo3531]

@@FreshCapMushrooms he's almost done building the 24" x 24" so I'll be using that for a while.

[@robertyoung8871]

We need a part 2

[@FreshCapMushrooms]

Coming soon!

[@ralphmalph6824]

Great production. Thank you. How would one test and verify that a laminar flow has been achieved? Thanks again!

[@daysensouth7325]

Genius

[@roypaul3412]

Hello, Great video. It seems that the Astrocel filters are gone. Saw them discontinued on most sites. Do you have a recommendation on another one to use?

[@paulgray2156]

Tony it would be very helpful if you answered the questions in your comments section because I have many of the same questions but you haven’t answered them previously so I won’t ask you again apart from that, great video

[@killerkennyas]

Awesome vid..thanks

[@FreshCapMushrooms]

Thanks! Stay tuned for part 2 :)

[@killerkennyas]

@@FreshCapMushrooms hell yeah..i have a 2x2..but wanna build a 2x4 and poof..you share your geniusness with us

[@FreshCapMushrooms]

haha awesome! the 2 x 4 will make life so much better- so much room to work :)

[@TheSpoonyluvin]

Advice for anyone seriously considering this project: Don't waste your time (like me) looking for a less powerful fan to use on a smaller filter (24x24) in order to save some money. If it's true that most filter's have a resistance of 1.0 in.wg along with a prefilter of .3, then the ONLY squirrel cage blower that moves air at that resistance is the 1TDU2. The closest runner up is the TDT8. This of course also assumes the 100 FPS is the minimum requirement for laminar flow. I'm taking him at his word on that. Had someone told me this before, it would have saved me a couple of hours. You're welcome :)

[@BoomerShroomer]

Yep, agree! I ended up doing all the research and came to the same conclusion! Dayton 1TDU2!

[@TheSpoonyluvin]

@@BoomerShroomer Yep! I'm very happy with it, though I wish that it came with mounting flanges. I ended up using some L flanges I bought from the hardware store, but it worked great!

[@ilikedogs870]

@@BoomerShroomer have either of you have any issue with the homemade flow hoods? Or are they effective w/ high success rate

[@FullMe7alJacke7]

Whats the highest FPM you could get away with before it becomes an issue? Does faster moving air become a sanitary concern if you go too high or is the problem going to be it just blows away things of important?

[@luisj.serrano5821]

it would be great to have all this in metric so the rest of the world could understand

[@vriddle79]

Some fans are rated in PA (pascal) ~250PA = 1INWG

[@zreeder21]

Any idea how many duck power the motor should be?

[@loganmolloy4220]

Can give links to the supplies. Like where do I get the filter the big one

[@unamused3420]

Great video and nicely documented steps! Where did you purchase the filter?

[@FreshCapMushrooms]

thanks!! Filter was purchased from a local filter shop, but manufactured by AAF flanders

[@JoeSmith-sl9bq]

references to where you bought them would had been cool

[@daurymiguelgonzaleztrinida8640]

Thanks for your videos they're very helpful, i have a question can i use a hepa 14 pre filter 16x25x1 just to get better inoculation and that wouldn't force the blower, i bougth flanders filter 21.75" x 37.25" x 6.375 and 1tdu2 Blower, thanks a lot and waiting for your reply

[@marcuswells9]

I can not fined a 24x48 filter do you have a source I can get one from. Thanks all your videos are super helpful

[@robbydockery1272]

Question for you. I have a fan I would like to know if it will work, and if so, what filter should I buy. I would like to build a 24x36 or a 24x48 flow hood but want to be sure to get the right filter. The fan I have shows to be a multi speed unit depending on how it is wired or could be wired with a 3 speed switch. 950 cfm, 1200 cfm and 1450 cfm I tried to follow the curve but had trouble finding the right filter. Any help is greatly appreciated.

[@melb5212]

Hi Tony. Great video. When you plotted the pressure drop of your HEPA filter on the fan graph y-axis , were you actually plotting the resistance of your filter? I am wondering if you needed to solve for the pressure drop as a function of the given flow rate and resistance on your filter and plot that, but I am not sure. I think given the speeds you operate at 800cfm is similar to the tested 1000cfm it wouldn’t matter if this is true, but trying to wrap my head around the fluid mechanics. Cheers and thanks!

[@CarolDunitz]

Do you have suggestions where to buy a reasonably priced HEPA filter for a laminar flow hood?

[@SkechArt]

fun with the flags :D

[@darrinchavez2086]

Could you run a high velocity fan?

[@GrowLLLTigeRRR]

Hey, thanks for the video. Those filters are pretty expensive. Are they washable/reusable?

[@lottie141516]

Can you link us to what you purchased online please

[@jospislt]

what kind of blower it should be, low or high presure?

[@MuhammadUmar-kw2mj]

If we modify more, and place glass room in front of this, is it also work for tissue culture or bacterial culture

[@joseruiz2747]

Do I need a pre filter specific to my hepa filter or flower fan? How can I find the resistance on the pre filter also?

[@funny11744]

Air velocity measurement : what distance from filter ? Any standard ?

[@chrischungy]

Could I tape a vent hepa filter onto a box fan?

[@Purity262]

how big of a room should the laminar flow hood be in? would a grow tent work as a "clean room" using the flow hood inside?

[@18Hands]

I was wondering you would suggest using an inline fan for the build. I have a fan that is 720 cfm and can't seem to find any info.

[@davesterchele2679]

We have residential MERV 13 filters that we use with a box fan to remove smoke particles while cooking. Would this work for a makeshift flow hood?

[@SackMyCook]

All of a sudden it seems more work than my lazy arris will do.

[@ducatista695]

Baby steps.

[@XxXAbbyAlohaXxX]

I feel like I'll never have this answered BCS no one in the comments seems to know about laminar hoods/ nobody is replying to q's. I will just have to call! good video regardless!

[@lundyracing]

What's the question??? Lmao

[@badoww4921]

how many 24 inch box fans would this use?

[@flyingeyefpv]

If I have a fan that is too powerful for my filter, can I use a control knob and find 100fpm post-filter with an anemometer?

[@gianfrancotrancillo9489]

what if i put 2 hepa filters of the thin ones, instead of one of the thicker ones? it'll still work? thanks

[@lucasmoraes707]

hi, does it need to have the metal net on front of the hepa ? I can't finde those

[@naturallydope247]

So if I have an anonometer and test it on my flowhood basically it needs to output 100fpm?

[@cjcarter7382]

Can this same fan be used for 24x24?

[@ginaluzchuquimantarivillar3224]

Hello, good video, I bought a Dayton 1TDR9, but in its curve the value of 1.3 inwg does not reach, it only reaches 0.8 inwg, my filter has an initial resistance of 250 Pascal, could the fan serve me? please I need your help, thank you very much

[@zerosyn6035]

what if i wasnt able to do the carpentry and didnt have the space for a full box/hood, and decided to use a BOX FAN behind the HEPA FILTER and that's it. will that work???

[@GodisGreat...89]

Hey...I hv a 24×24×6 inch hepa filter with pressure drop of 1.3 including pre-filter...Is 480 cfm blower after seeing the graph ok for this.thnx

[@richardmullane9279]

Can you tell us where did you buy the filter

[@danyoung3245]

Is there anywhere that you can buy a pre-made laminar flow hood that would be adequate?