How to Build a Corsi-Rosenthal Box
HTML-код
- Опубликовано: 27 сен 2024
- Richard L. Corsi, dean of the UC Davis College of Engineering, explains how to build a Corsi-Rosenthal box. Dr. Corsi is an internationally recognized expert in the field of indoor air quality, with a specific interest in physical and chemical interactions between pollutants and indoor materials. His concept for a low-cost, accessible, and effective air cleaner, the Corsi-Rosenthal box, is now being used as an open-source do-it-yourself approach worldwide for reducing exposure to the SARS-CoV-2 virus, wildfire smoke and more. For step-by-step instructions, visit: engineering.uc...
![DDG & G Herbo - Nosey [Official Video]](http://i.ytimg.com/vi/I9Ra0Zc2NlQ/mqdefault.jpg)
My only difference, was that my fan shroud was on the intake side of the fan. I used the other half of the fan box, and cut a hole in the middle of it that was 2 inches in diameter smaller than the tips of the fan blades. I think it might be a better shield to keep air from coming in the corners. I also used tape to shroud off the corners on the outflow side of the fan, just to be sure. I use 1" MERV 8 filters on the outside to catch larger dust particles and hair and stuff, then 2" MERV 13 filters for the inner core.
When we have forest fires up here in Oregon, it really clears the whole apartment in short order.
And we get the smoke from your forest fires in Idaho 😂😭
@@SalivaRUclips They're not my fires. Blame the weirdos who go out into the woods.
@@SalivaRUclips and in Utah, too.
@@BigFrankieC I blame the weirdos who delay until the blaze is big enough to get federal money.
@@DistracticusPrime I blame fire. I think that in this situation, fire's the real jerk. Stupid fire.
I use 4in thick filters for better flow and less stress on the motor over time. Also for everyone asking why not use filters on 5 sides, it's easier to find packs of 4 lol
My furnace has a 4-inch filter box and they are quite a bit more expensive. I get a 2 pack at Home Depot for about $40. They do last a lot longer though.
I have been taping two 1" filters directly to the box fans for years. Not the cheap ones either; I find that a Merv 14 primary and a Merv8 pre-filter works really well to keep allergens down. Same fans, very little stress on the motor.
Stress on the motor? Ridiculous.
@@NukeChiefMech it is...
If they would know a little bit about fluid dynamics they would know that the air resistance for the fan actually decreases with less airflow (i.e clogged filters), because it produces a lower pressure zone, which reduces drag.
But hey. I'm just a guy on the internet.
I've been doing this for a lot of years to filter sawdust in a woodshop, I wasn't even aware it had a name lol. Who decided these guys were the first ones to realize a box fan with filters on it operates like any other commercial air filter system?
Woodworkers have been making these for decades. Not sure we should be calling these Corsi Rosenthal.
Because they made a video. Lol
Guy standing by himself wearing a mask has no credibility.
@@skeptigal4626
More than you
@@skeptigal4626 it's probably in California. You gotta wear a mask while you sleep
How long ago did this become known as a Corsi-Rosenthal box? I built a super size one these 20 years ago using wood frame with casters to hold 8 filters and a 5000 cfm drum fan. It was big but it filtered a lot of air quickly in my workshop.
The more I think about it and reed all the comments, Dr.Corsi being a dean of a College of engineering and a international expert taking credit for this idea is crazy. It would be like naming fixing a torn piece of paper with tape and calling it ".....'s paper repair system".
Don't you love how this guy just loves saying his own name? And his build skills are up there with my son's - when he was 6.
We had these in middle school in wood shop in the 1990’s. This is not new.
yeah...this is not new. Also, duct tape is not actually the best way to do this, you really need the aluminum tapes HVAC actually uses to seal ductwork. Duct tape dries out.
Frankly, a better design is with two filters forming a triangle with the fan.
@@truantray Why would you think the triangle one is better? Curious cause I built a triangle one with aluminum HVAC tape and planning on upgrading to a square one like what is shown
I was wondering the same thing, this is nothing new but they just put their names on it and act like they are the first ones to put furnace filter on a fan.
Been making these for a couple years now. I use a sheet of formica cut to size for the top & bottom, and put 1/2" weather stripping around the edges of the fan.
That's the Raucina/Ruby box invented 45 years ago by me and my dog. Except we did it right and kept the fan on its feet so it didn't start a fire when the plain bearing got smoked by laying it horizontally. So much for Universities.
Why not use a fifth filter element on the bottom as well and hang the entire filter box? I build filters for my shop like this more than 30 years ago using five filter elements. The fan was one of the old style box fans which were heavier and much more powerful that the ones available these days. I vented the fan into a duct I made from sheet metal to the outside. Instead of simply taping the filters to each other, I constructed a sheet metal frame with slide in filter element holders sealed with silicon "O" ring type gaskets. The entire thing was air tight except through the filter elements.
It's a great thought, but it is extremely dependent on how powerful your fan is. You need a certain amount of static pressure to pull air in, too much and your fan will actually pull in surrounding air around it without actually pullling all of the air through the filters and push it back out too easilyy, something people forget to mention. Imagine placing a plastic straw into a bag and you start sucking on it. Well, you mouth creates perfect suction, but fan blades attempting to pull air out don't. errors in curvature of the blades, etc, will not pull 100% of air through the filters. This is an easily provable experiment. Take a filter and place it in front of your fan where your fan has to push air through the filter. seal all air gaps off. If you hover your hand over the back of the fan, though it only pulls air in, opposite of the filter, you will feel air blowing backwards back towards your hand. Perplexing right? Your fan can only pull air once way, so how can it come back at you? That is all of the immense amount of air not being filtered and being backflowed.
@@Phalenx15 'It's a great thought, but it is extremely dependent on how powerful your fan is.'
Exactly, but you have it reversed. More filter surface area means more area for the air to be drawn through. That makes it easier on the fan with 5 filters, not harder.
Restrictions reduce as you add more pathways.
What's the point of making one of these only to vent it to the outside?
I love how Dr. Corsi starts off by saying "What's become known as a Corsi-Rosenthal box" and then proceeds to awkwardly say "Corsi-Rosenthal box" more than a dozen times, it was like a comedy skit where can he work it in next. I remember seeing a bunch of these in New Orleans after Katrina in 2005 and the greatest benefit was that they use readily available materials which let people produce them easily in the close aftermath of storm flooding.
He jumped on the Covid Cult train in a sad attempt to make a name for himself. Sad.
@@tombiggs4687 At least he's trying to do something and not whining about having to where a mask or pretending that pharmaceutical companies making huge profits means that a vaccine is "bad".
@WeavingBird if I had tried to apply my name to a concept as trivial as this much less one that I didn't come up with myself I would have been expelled for violating the honor code. You're not talking about the discovery of some novel method for extracting DNA from a cell you're talking about pulling air through a filtration medium with a fan... something that was first done over 150 years ago.
I can't imagine any scenario where I'd want to look at research into something generic like this from a specific person where I wouldn't just search for research done by the person's name. It's the exact same outcome - people find the research searching for your name with the difference being you don't have to name something after yourself which you didn't create.
The culture in academia is bonkers, in my experience outside of government politics I'm not sure I've seen bigger egos present anywhere. I'd say the number of times the guy mentions it - even to the point of it being awkward - makes his intentions clear.
I love how he is celebrated like this expert, but he has no idea what he’s doing. MERV 13 filters do not filter the “cold”. He’s using toxic duct tape to seal it, and no pre filter no carbon filter. It’s amazing! I’m not an engineer, just a nobody, and I know 10x more than he does about his own job! Amazing!
@@ZxAMobile pre filters are not needed for merv 13 filters. Pre filters are only used to extend the life of HEPA filters.
Almost all cold virus travel in aerosolized particles which just about any air filter will trap (they are relatively huge).
HEPA filters also outgas, so that’s not much different.
Carbon filters don’t actually filter particulates. It just reduces VOC / odor until it is saturated. Most air filters don’t have the carbon filters sized correctly for the CFM. So they don’t do anything after a while.
Dunning-Kruger.
I’m a woodworker, and I’ve been using this for years. My grandpa had one in his workshop back in the 80’s. So…. It’s just a redneck air filter, not a Corsi-Rosenthal box.
This is the “it took a 1/2 million dollar education and pHD version.
Btw: phd stands for post hole digger wannabe
The two nutty-professors.
Nah he clearly invented it.
@@iloveit9468 ok ill tell my robotics engineer friend he wasted his time and that his 300k job is for losers. I'm sure he will be happy digging holes, competing with illegal immigrants for jobs.
@@JimmyRussle exactly you tell em!
I made one of these on a whim about 8 years ago to deal with the spring pollen here in Georgia. Turns out I forgot to take the time to name it after myself!
same here lmao
Parallel engineering universe.
He even built his face into the unit. You can hear him struggling from rebreathing his exhalations.
Osha has known how horrible this is since the org began.
@@CoincidenceTheorist Bizarre. So you guys really think surgeons, car painters and the entire silicon chip industry are all dying from 'breathing their exhalations'. When did this genius idea first come to you, given that masks have been used since the Civil War to stop the spread of disease?
First to publish gets the credit.
Thank goodness our Uni’s are out their reinventing the wheel. Where would we be without them!?
I can't wait for them to release the video on the Corsi-Rosenthal Paper hat. - UC Davis Engineers are on the cutting edge of innovation!
LMAO 🤣👍
What's up with the industrial mask? OH yeah it's California. Idiot capital of the world.
It’s a novel method to reduce viral loads in the environment, not sawdust.
I made one of these out of wood years ago to help control dust in my shop.
I copied the design from someone who didn't claim to be the inventor.
Most people call this a "Box Fan Filter."
This one uses MERV-13 filters and is intended to filter virus out of the air, so its purpose is a bit different even if similar in implementation.
@@johnklein338 I built mine years ago and used MERV-13 filters. Woodworkers have built these for like decades. There's absolutely nothing nothing new that these self-important professors have built here.
@@linsen8890 actually important profs have saved countless lives. Sorry you're sore about it. Not sorry.
@@johnklein338 😂🤣😂🤣 I'm sorry that your reading comprehension is so poor. Not sorry.
This design was in widespread use prior to 2020 when it was “invented” by these guys and they put their name on it.
I was going to say, this was really common when I grew up as a cheap way to filter paint booths... and you can probably find many RUclipsrs using similar solutions for makeshit paint booths as well.
It's also really common to filter wood shops on the cheap...
@@looncrazfun fact, they also invented the Corsi-Rosenthal mouth and nose muzzling device
But don't forget this guy has a PHD!
PhD: pretentious huge douchebag
Great DIY project. If I may suggest, use the other side of the box as a template and cutout the face of the fan. Tape that down so the sides do not create a space as with the corner pcs. Thanks for the video!!
I built this a month ago, its been running by my front door to protect us from my unmasked neighbors. I also have a very expensive airmega coway. This works better! In my 1000 sq ft 2 bedroom on high speed I can get PM 2.5 and PM 10 to 0. There is no way my coway could do that. It's a little loud on speed 3 so most of the time its running on 1 speed. My dog also has unexplained environmental allergies so she licks her feet and has watery eyes. It's completely cleared up now as well as my own dust allergies. Thank you so much for this!! I got my filters from costco - 3m 2200 and the box fan from Walmart, a little under a $100. My husband has a CR box running in his office where he is the only one that is masked. We are both still covid free while his entire office has had covid multiple times.
🤣🤣🤣🤣🤣🤣🤣
Woodworkers have been making these for decades. Not sure we should be calling these Corsi Rosenthal.
How did something this basic deserve a double creator name like that? It’s not the first time someone builds something similar.
huh - weird, created during the "pandemic"? I saw 3 of these in our wood/metal shop in high school in the 1980s - yes - using simple box fans and air filters constructed exactly like this (using metal tape). Now it's someone's named creation? 👍
yes, the "pandemic" significantly accelerated the transfer of power in our society to the useful idiots and communist busybodies who are now all stunning and brave geniuses, and in fact are themselves in all their sanctified glory, The Science.
These have been around for decades. I built 1 back in the 80's to clean the air when I was cleaning the basement where I lived.
The fact that you named this "box", after yourself is hilarious. Woodworkers have been doing this for years.
He didn't name it after himself. The fact that you assume you know things that you never bothered to research is pathetic. Stop making-up stories so you can pretend that you know what you're talking about. Here are the facts you couldn't be bothered to discover on your own. I share them here for the benefit of others:
In August 2020, Richard Corsi, an environmental engineer and the incoming Dean of Engineering at the University of California, Davis, spoke with Wired reporter Adam Rogers about an idea he had for combining multiple store-bought filters with a box fan to improve the efficiency of home-made air filter designs. Rogers contacted Jim Rosenthal, the CEO of filter manufacturer Tex-Air Filters, who had collaborated with Corsi at the University of Texas and in the Texas chapter of the Asthma and Allergy Foundation of America, to run some tests on a single air filter attached to a box fan. Inspired by Corsi's idea to use multiple filters, Rosenthal later came up with a five-filter design. **Rosenthal named it after Corsi,** although after a New York Times article mentioned the boxes by that name, **Corsi tweeted that Rosenthal really deserved the credit,** and that he preferred the name Corsi-Rosenthal Box.
You don’t call a PhD "Piled high and Deep" for nothing.
Yup
@@blipco5 How embarrassed are you to realize that the guy in the video didn't name the box after himself? How embarrassed are you that you believed the commenter, whose ignorance led you down that path, and you weren't smart enough to avoid the trap?
Probably not at all, because you likely share that ignorance. A smart person would realize their mistake and correct it. Will you? Probably not.
So, maybe it's only the stupid people who refer to "PhD" as you do.
It’s for viruses, not sawdust!
No woodworker thought this was reducing viral particles in the air.
Source: I’m a woodworker.
All I do is plop a filter behind the fan and the suction keeps it attached. Works decent to collect dust and is a lot easier to replace the filter.
Until the fan motor burns up. Yes, that is a great idea. Stand by with the fire extinguisher.
Not sure when this was named after him... but I've been building thee for at least 10 years as a cheap option for workshop air quality. And it wasn't my original idea when I started. Pretty sure I saw it on a woodworking channel on RUclips.
So, you've managed to come up with a name for a contraption that's been in use for decades. Good job!
However, when you take an existing design and call it your own, that's considered "plagiarism".
Edit: There are videos I found promoted on this very page that describe how to make these contraptions that pre-date this video by YEARS.
Boy you are gonna be really upset when you learn what they are calling "tool with stone head". The youngsters are out of control.
You can use less merv rated filters with thin foam to lay on top of them sprayed lightly with oil and that will attract and hold much more dust and extend the life of your filters. Just wash the foam and reapply the oil.
For a hot second I was concerned that the pom poms were a required element and I hadn't secured any - but no, that's just a charming touch of school spirit. Thanks Dr. Corsi!
If you close the top off to 2 " smaller radius than the fan blade it will greatly reduce the vortices of unfiltered air from circulating.
Shouldn't an engineer know that? Especially the dean of the engineering school!
I have one of these running in my basement all the time except I used one 4 inch 20 x 20 filter on the intake. Great for kidney looping air to lower allergy particulates. My hvac guy said we have the cleanest air he has ever measured.
The problem with this design is that the box fan is not designed to pull a static load. it's designed to move a volume of unobstructed air in one space. This is why sitting a box fan in a window doesn't run air though the entire house when you open another window on the opposite side of the home. The fan does not create enough static pressure. What you need to make this work efficiently is a tube-axial fan (drum fan) that is commonly used in forcing air through long large diameter conduit. It moves an enormous volume of air like a box fan, but it performs more like a centrifugal fan like on most HVAC units. Tube-Axial fans are used in paint spraying booths where the filter is placed directly over the intake shroud (Which, is already round). and usually have the motors located where flammable fumes cannot ignite with the electrical sparks that are created on the brushes with induction motors. The actual design of the "Corsi," fan is mimicking that of an exterior air conditioner heat pump housing. The box fan is a great idea until the filters start to clog, and the fan motor will burn out. However, for $65.00 it's not much of an investment to lose sleep over.
That's exactly what I was thinking... and this is the dean of engineering that names a simple box filter after himself that thousands and thousands of people have already "invented" and built themselves to try to keep sawdust down in their hobby shops.
Well, woodworkers have been building and using them for years. I have a similar dust filter in my shop, built using two filters stacked, and I've been using it for years without any problems with the fan. They create plenty of pressure for this kind ot application.
excellent comment. Can a basic test of static load on a fan be done with a sealed box (or metered output), a manometer, and a fan? Trying to understand the concepts at play here
Good comment, thanks.
I've done the two windows one box fan trick for years, though, and I can feel the air being pulled through the house. I'm sure a drum fan would be more effective but, as far as I can tell, a box fan works too.
Thank frick someone finally said it. And like wph above said, that THIS guy tries to put his name on such an old DIY thing is something else. Incredibly distasteful if you ask me.
Dude watches a few videos on wood workers building shop filter systems then makes a video of one he made and named after himself as if he just invented something new. Really shows the value of college education.
prob in a room all by himself too, looking like a platypus or something.
Marketing. It's not who had the idea, it's who sells the idea.
that's how probably half of all "discoveries" and "inventions" are made... someone with an education sees something made by someone who is a real world pragmatic problem solver, steal their idea, maybe improve upon it, maybe not, then name it and patent it...
@@Spiritof_76 Edison....
@@nomchompsky2883 Got any statistics?
Wow a man that gets right down to the point no long winded conversation. Hats off to you sir very well demonstration THINK YOU !!
During the "lock downs" the employer I'd worked for at that time had our Air Conditioning Techs (myself and others) build very similar device and installed in a building for our covid-19 positive patients and in their "wisdom" said we had to exhaust this now filter air to the outside. There was no upgrades allowed to the AC system in anyway. This was a state run hospital.
_"eject all that clean, filtered air outside at once!"_
ALL WHILE MASKED. THANK YOU. DUSTY✌️
For a city man such as myself, this is great stuff. I regret though that I only found out about this circa 2023 not 2020 but hey, I did buy myself 2 retail air purifiers and now I can afford to build my own. GREAT.
Thank you for the video and detailed instructions! I looked around and wasn't able to find directions regarding the best speed at which to run the fan... low/medium/high? Also, how often should the filters be changed?
I just searched a bit, and three sources said the filters should last 6 MONTHS, but if they look dirty, change them sooner.
I also read that because of the noise, LOW or MEDIUM is good for occupied rooms, but running it on HIGH will "move more air" so maybe more effective on high?
@@GeeAre is correct, it is a trade-off between noise and the Clean Air Delivery Rate [CADR]. Most fans will list dB for each fan speed and it may be worthwhile to include that in consideration when selecting a fan.
Medium is usually the happy medium. You can find a number of CADR estimate papers online and there's a reasonable jump between 1 to 2 but less between 2 to 3 for most fans/designs. But if the room is unoccupied and if you want max cleaning for a shorter period of time (say a teacher who wants to eat in their room after students leave), definitely run it on max.
Electrostatic filters are good for 90 days only, unfortunately. And you really need the electrostatic properties to catch virus-containing particle sizes of things.
@@emma70707Do you mean they last 90 days if they're running 24/7, or they last 90 days regardless of how long the fan runs?
The problem with all those kind of videos is that they are talking about CFM but nerver justify there sayings. They should mesure te air flow before and after building the box and then compute the CFM or M3/h. I think we would have some surprises with the results.
Amazing I would have never thought that it would take an engineering degree to build with tape and cardboard. Just think of all those people who managed to do it without paying for an educator to formally instruct them. There must be plenty of "uneducated" duct tape engineers out there. Don't get me started on the ego behind naming their cardboard and tape wonder. Is there a patent pending?
Wouldn't be surprised if there is a patent on the way. People like this get where they are through relentless self-promotion, not by actually accomplishing anything. Would you want to pay $100k+ to send you kid to a school where this smooth-brain is a Dean? What a joke...
This dude *loves* saying his own name. He thinks if he keeps saying it, we'll start to think he actually came up with this decades-old DIY shop filter.
Posted 'Apr 15, 2022'. But pretty sure it was actually invented on April 1st.
He's pretentious as f
Maybe I should stick a stick in some juice then freeze it and name a popsicle after myself. This box filter idea has been around forever.
Used this method with regular air filters during renovations. Worked really well to keep the fine construction dust to a minimum. Also helped with my allergies during windy season.
i just took a filter and put it on a fan. worked like a charm. not sure if it will effect the fan life but... who cares for 24 dollars and 10 for a filter 😂
You might care when the fan motor ignites.
This is excellent! I am going to put a computer inside it because I am sick of dust
Wow, that's a great idea! Also, large fan will ensure good air flow for cooling your computer.
Love the idea!
@@sander_bouwhuis Actually.... it probably will NOT ensure good airflow. You would need to narrow the opening (Bernoulli effect) to get enough flow.
That is a truly bad idea.
Woodworker’s have been building these for years to clean the airborne dust out of their shops.
leave it to academics to jack themselves off about slapping some filters on a fan. these people are beyond useless.
Now, is that special Corsi-Rosenthal tape, or can I just use the duct tape I have already? And what about the Corsi-Rosenthal box fan? I sure hope there’s a kit I can get somewhere…
This is just a home made air filter that we all made years ago. There's no name to it, lol. This is a huge version. You can also just attach 1 filter to the intake side of the fan and seal it with tape. Done, and cheaper.
no actually. if this guy was any good at explinations you realize but its a stolen design. the point of four filters is noit that 1 wont work but that 4 has better air flow
And here is an example of how an idea is taken, renamed, and then sold as new.
My furnace uses 20x25x4 MERV 12 filter. Can’t I just turn on the furnace blower fan?
People, myself included, have been making them for decades for shop air filtration. We didn't have a fancy name for them and no real engineering went into it, just that old "necessity is the mother of invention" thing.
I made one of these in the past, so I think it's actually named after me my dude.
Uhh these been around decades and aren't named after you. I built one in the 80s in woodshop. A better design is 5 filters, the 5th filter in on the bottom and raised off the ground. and have fan airflow pointed down so the fan is pulling air down and isnt blowing air turbulence upwards blowing particles around. For wood shop or air spray use to 8 to 9 filters stacked on a frame and a very high flow fan . But this requires building a structure.
The Cadwalader Air Purification System: Tape the filter directly to the back of the fan. Cheaper, faster, and I did it 25 years ago during the Central Florida Muck Fires. My house was the only house in the neighborhood that didn't smell like boiled swamp.
Interesting, This Old House has a video three years older than this one building the exact same thing...
“MY invention! MINE!!”
I've done something similar as a dust collector by letting a single filter get sucked to the back of a box fan. I didn't feel the need to call it a Milford box 20 times in a video. LOL
Great for an air filter, but does not stop viruses.
I noticed the prof was careful to always specify "aerosol particles". Those are big enough to get stuck in some filters.
The naming might be obnoxious but hey these are really good instructions!
Facts, I could give two shits if "woodworkers have been building these for years hurr durr" well one of them should have fucking named it already then.
How often do you have to change the filters?
about as often as he changes his ineffective n 95, lol
drinking game: take a chug every time he says, "Corsi-Rosenthal".
This old house built the same thing over 3 years ago... We had one in out tack room back in the 70's. It didn't take an engineer to come up with it either.
A variation of this is cut the filters to the shape of the inlet of a wall mounted split system air conditioner (which is usually on top of the unit out of sight). I have a HEPA and a carbon filter (for the neighbours wood heater smoke) on mine and it works really well. It has minimal impact on the air con and keeps the insides of it clean.
I use this kind of system in my garage for painting, except I have the filters in a row and the fan pushing air out. I put them below the garage door seal, so it would be floor, filters, door. All the overspray gets trapped by the filters and not into the neighbors. For fan I used a radiator fan from the junkyard.
will it still be effective enough if pleats are horizontal? I was sent the wrong sized filters (18 x 30 x 1) and I'm planning to use them to make this.
I’m pretty sure it will be just as efficient horizontally. He suggested the vertical alignment so that the filter material wouldn’t sag over time. I guess it will last longest aligned vertically.
I can see how they would sag more in a more humid environment.
You must drink every time he says "corsi-rosenthal box"😮
why are people giving it that name when its design has been around for years
They're hoping people like you and I don't notice and call them on their bs.
I made a variation of this in 2020, speculating that COVID could be filtered out. I used it in my office to create a clean-ish bubble of air that sat inside of. Don't know if it worked but I'm one of the few in my office that never caught COVID.
Everyone take a shot everytime he says Corsi-Rosenthal Box. You will be drunk in 8 minutes.
Other than dusty air blowing through a fan motor over time, is there a specific reason why airflow is in through the filters and out the fan? I’m doing this for workshop fine dust, and I don’t want air blowing out the fan at me all the time while I’m working - I wanted to have the fan drawing air into the box and pushing it out the filters.
That's what I have, it's all just horizontal.
One reason is that when the fan is blowing out, the air stream encounters no resistance blowing into a large volume, and pulls air evenly across the filters.
When blowing in, the air flow will be turbulent and impact some areas of filter more than others.
Aside from that and keeping your fan clean, no huge reason. Some people build them with the blower pushing in, I think more common with people filtering shop dust near a power tool or work surface.
No. The fan needs to pull air through the filters.
most woodshop fans i see are reverse , rember to flip teh filters not just fan if your filters are directional. some have reinforcements so backwards air flow they buckle The 3D Handyman has a good demonstration
Pushing air into the filters reduces the airflow.
Thank you Dean Corsi! I'm making one of these tomorrow as my grade schooler lost the masks not required in school COVID lottery.
WTF, that sounds barbaric. Everyone knows that crap is all fake and gai, I've been saying it for 3 years. I'd be pulling my kids out of public school before letting teachers and admins treat them like stupid livestock. They are slow dripping the truth now though, and one day you will accept it was all fake and gai and meant to harm, I hope, and stop participating in the daily lie.
I think for your kid it is better to teach them when following the rules is wrong, bc 100% adherence to the rules is not what kids should be learning. They would make perfect hitler youth though, as it was not only the rule to finger your neighbors for the stasi, it was considered Patriotic. If the rule is stupid and a lie or is in some way harmful, they should not be following said rule.
Please stop going along w the nonsense, it's a mental illness to think face masks do anything but harm. Your kids are old enough to see you break a rule that hurts you and makes no sense. Just explain why you are breaking the nonsensical rule. Please do not be like Milgram's experimental subjects, 80% of whom were unable to say no, no matter the circumstance, as long as an authority figure was telling them what to do, they did it. Participants administered a shock that would end another subjects life, just doing their job. Only 20% were able to just say no.
Idk if you saw, but a bunch of Nurses and hospital staff have participated in genocide bc they were unable to say no to administering Remdesnivir that killed patients. Good luck getting all the sheep to recognize they have put together the last piece of some evil puzzle that killed 10s of 1000s of people though.
The masks do nothing. Grow a brain.
He's more like Dean Martin IMO.
Thanks for the helpful video! Can you tell me big of a room will this work in, and when the filters would need to be replaced? Thanks!
Does anyone have this information?
From other videos, they said 900 sq. ft. giving 3 complete air exchanges per hour. They suggested one move the box in proximity to where you are. This was from the "This Old House" guys on RUclips.
The ballpark rule of thumb is 1 CR Box for every 500 ft² of floor space if you want 6 ACH (Air Changes per Hour.)
Pretty big. I put one in the barn. My sheep love it.
It's a neat idea, and will doubtlessly be helpful during pollen season, but I'm skeptical that these filters can stop and capture viruses.
Watching the video since I think the idea is useful for those looking to reduce PM 2.5 (burning season pollution).
Ha I just ended up re-inventing this box, but on a micro scale, to remove VOCs and small particles from 3D printing, in the "inner" space I placed some activated charcoal,
it requires a higher pressure fan, but it filters both particles and VOCs
I've been doing this for a decade
New drinking game take a shot every time he says corsi-rosenthal box 😂
Do we need to change the filters periodically?
Yes. One will need to build a new one (can re-use the fan) once the filters are dirty or airflow is notably reduced.
They never get dirty. So no.
Just tape a filter to the back of the fan. It takes up less space and the filter is easy to replace rather than building a new box every week or so.
Or, tape one to the back and front.
Hello Dr. Corsi,
I was wondering….I am building one with 5 sides filtered with an industrial box style fan.
My question……If you placed the built purifier suspended in a stairwell exposing all 5 sides would it draw more effectively from the 1st and 2 floors? Or would the result be the same placed on the ground floor?
My home is 1100sq. ft.
Thanks in advance.
1. With 5 sides unblocked will get you 25% more air flow
2. IMHO, you want it placed where people gather / next to people to be more effective
What was the name of the box again? I think it missed you saying it.
What would happen if you reversed the assembly so the fan sucks in air and pushes it out of the filters??
How about reversing the air flow, putting the fan on the top or the bottom (elevated) and pushing air inside the box (arrows reversed)? That will keep the filtered pollutants inside the cube and the air will be gently dispersed from all sides. If the fan is put on top, a coarse filter may be place on top of it as a safety measure. I am going to try that.
Here is a proof of this - ruclips.net/video/fixd7LqnWow/видео.html
The particles inside will probably accumulate and stay airborne due to the turbulence introduced by the fan. The fan itself will also get dusty.
This will cause particles to stick to the fan.
Reversing the airflow will mean the fan is handling dirty air vs clean. The fan will get dirty much faster. A problem if you intend to reuse the fan.
increases watts the fan uses. Will cause it to heat up. Starve a fan of airflow and it uses fewer watts, stop airflow out of the fan and it heats up and uses more watts.
Thks oh so much
Can the fan be flipped, and push the air into the box rather than pull the air threw it
I'm curious if the fan could be switched out with one of the side filters so that the fan now offers more support, and it still has a full range of filtered intake?
This could make it more cost effective by allowing you to use 1-inch thick filters.
Thicker filter means larger/ more pleats. More pleats means more surface area for the air to pass through and better filtration.
I've never heard of a CR box collapsing.
@@DonnaAndCats with 1 inch thick filters, they become very flimsy. As well as a more humid environments.
I've done it now with just 2 filters in a "V" formation, and I've noticed it still has the same cfm as it did with the 4 boxed frame style. (But I also have the slightly more powerful box fan lasko makes). All in all the only difference I can determine would be the need to replace filters sooner. But I'm looking into reusable hepa/ionic filters, they're just darn near impossible to get in a 20x20 design. But they would be an excellent, long term solution. And perhaps allow 2 fans opposite each other with a 3 filter system between them.
@@carterscustomrods Nonsense. It cannot have the "same CFM" - since the surface area is doubled. More surface area, more restrictive to airflow, less CFM. Right? Right.
@foobarmaximus3506 it had the same airflow that it did with 4 filters. But, the cfm dropped a lot quicker as the filters started to accumulate particulate.
After about 5 weeks, the airflow was noticeably lower, and the filters were darker (as one would assume in a 2 vs 4 filter setup).
So I ended up taking my 2 filter V system and dropping it down from an M13 to an M8. But I'm using mine in a woodshop and I don't need to trap virion, or anything like that.
But when filters are new, and fan is on high, the filters didn't change airflow in any noticeable way. But having the stronger Lasko box fan mightve made a difference.
The only changes in airflow I was getting was if I didn't have the corners of the fans face covered. That actually slowed down airflow when I assumed it would increase it. Do you definitely want to have the face of the fan setup with the rounded corners on the finger guard.
This is OUTSTANDING! I have asthma and am going to build this today!
Question: an I use an exhaust fan instead of the regular one? Is there a way to box the filters so the dust is not exposed at sight. Yes, the fan will attract air and expulse it on top but the filters are retaining the dust that will. OST likely fall out when I stop the fan. I think .. am I wrong?
This should be called "the internet" filter, there have been variations of this for ages, well before the pandemic, also, as an engineer, it is extremely inefficient to make this air tight, you are recirculating the air inside the very same room, also, pulling instead of pushing, so there is literally nothing leaking
Take a drink of your beverage every time he says Corsi Rosenthal Box.
You should look into creating a 3D printed shell that seals off the bottom and has arms for the filters to slide into that automatically seal the gaps, that way you don't have to go through this process every time you need to change the filters. Duct tape can stay on the shelf, cardboard could go into recycling or be repurposed, and the 3D shell could be printed from recycled bottles. Zero waste, zero stress set up.
I was thinking that an additional set of filters are attached on the outside of his design so they can be replace after a month or two. (in this case, its burning season so alot of PM 2.5 pollution)
@@darwinjina that's basically how a good hepa filter works, it has prefilters that are like a scouring pad, back of sponge, brillo pad, w.e you call them locally, on the inlet. You replace those prefilters a lot more often than you replace the main filter. Well, not by manufacturer suggestion, but in practical application.
@@penguinjay makes sense to me. Thanks
Zero effectiveness. Yes, great idea. LOL
You’re talking to someone that still wears a face diaper and thinks he reinvented something that people have been making for decades 😄
Lasko makes a lot of fans. Does this look like a 20" to you? And - does it make a difference as to whether we use a steel-rimmed fan vs. plastic? Plastic would be lighter, but maybe you need the weight of steel to stabilize it...?
I don't care what you call it if it works.Do you know the cost of commercial filters these days? I plan to build one for my attic to help filter the dust from the roof and insulation
Would be a pain to rip off all the tape and rebuild the box every time you need to change the filters. Total rebuild basically.
Exactly
Someone just mass produce a skeleton to fit the filters and hold the fan
Exactly this is what stops me from doing this. I really don't feel like doing this every few months.
Although they appear dirty fast, they last at least 6 months. Pretty sure testing showed them still working well much longer than 6.
I think the idea is to cheaply outfit classrooms with them. Possibly last a school year.
@@DonnaAndCats
1. Are there washable filters?
2. I see they now come in sort of a cardboard box, but I can imagine creating a frame where I can slide new ones in. That would save some time.
Thank you, Dr. C! ⭐️⭐️⭐️⭐️⭐️
Anyone know how to effectively mute the sound of the box fan? Thinking about meeting spaces and background white noise distracting from conversation.
ROFLMAO!!! Makes a video in the year 2022, while still wearing a mask and mumbling through the whole thing! Was this filmed before or after dinner at The French Laundry?
Where should I keep this box in the living room ?
Kinda wish the flow direction was reversed so the box would be a container for all captured particles
Actually I take that back because it relies on negative pressure to not blow debris through the duct tape joints
Also, what micron level would this block? 0.2mu?
I'm wanting to make a series for my woodshop that will be capable of capturing airborne particulates from aluminum and MDF (Medium Density Fiberboard).
MERV 13 would clog up very quickly in a shop environment. For those situations a vacuum at the point of material removal is best. If you do build something like this a much lower MERV rating would be better.
Not even close.
According to the Wikipedia... Depending on the power of the motor of the fan , it is capable of CADR between 600 to 850 CFM. Has this been tested truly as true CADR? Because there are many instances Air Flow rate is being mistakenly taken as the CADR. Air flow rate and CADR are not the same...
What ply tissue should we buy to stick on top?
I built stuff like this when i was a Toddler.
We had these at OSU in 1974? Used in the ag lab when cleaning seeds (puts a lot of fine dust in the air).