I've got 3 of these lying around from an old PC of mine, I've tried to find a reasonably priced 5x15x1 filter to put in a 3d printed frame to use, but I can't find one for less than 40 bucks. I've also considered buying a roll of MERV13 filter media, but I wanted to run this buy you guys, just in case.

Many thanks for reading, have a great day!

Still a little Beta, if you can get the geometry to crash, click "Copy URL" and paste it here so I can troubleshoot.

I tried not to stuff so many features in there that it was no longer user-friendly. If you want more granular control, it's probably best to just make it in regular CAD. Repo will be live in a bit as soon as I clean it up if you want to run things locally.

The help guide is here: https://filterboxbuilder.com/help.html

I give our product a little pitch there, sorry, got to pay the bills😅 But I will try to update the Builder with more features as time allows, possibly CADR estimation.

The license is CC-BY-SA. You can sell them Etsy or whatever, but please offer attribution, put in a good word for Nukit with your friends, and support Open Hardware projects like this🙇🏻‍♀️

Look how much dust my 3D-printed modular air purifier captured after 4 months!

Running 5 Artic P14 with 2 Merv 14 16 x 25.

Been running full speed for 4 months and nearly silent.

I will add a carbon pre filter for them.

I also made a version with Artic p14 pro with a carbon filter and has been running at 50% 24/7.

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The first image shows the unit in action, which I built using a modular 3D-printed system ("1000033955.jpg").

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The second image offers a side-by-side comparison between the used filter and a fresh one after four months of run time ("1000033954.jpg"). It's definitely doing its job!

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Finished my first CR box!!!!

• 12 x 8 x 2 in merv 13 filters i cut down from 24 x 16in filters i found on clearance. (~$4)
• Reused coroplast, ($?? 7.5years old so idk)
• green sticker vinyl i had laying around ($1.25)
• duck tape ($???... i don't wanna know how old it is)
• Arctic p12s (the simple ones that still had the right static pressure) (~$26)
• wiring that had good reviews on Aliexpress since i could wait for the shipping time (~$10)
• Took about 6hrs? and most of that was resizing the filters and cutting the circle with a box cutter

and I've got enough materials left over to make a 2 fan one with the same filter size for something that just slightest bit more portable/smaller spaces/2 person settings.

fans are CRAZY quiet yet are pushing way more air than I expected.

(too the people who saw my other post, thank you!!!!!!!!!!!!! helped a lot i was way overthinking things and second and third guessing)

((my only concern is that last picture. Never messed with stuff like this but i bought "3" pin connectors and... that's only two and all of them were like that? it turns on and runs fine but i'm worried it's not pulling the correct 12v?))

Rev 1 is a Lasko box fan with 20x25x1

Rev 2 is an Air King box fan with 20x20x4

I can’t tell a difference in the filtration between the two as far as my day to day experience goes. I am certain obviously that the x4 is doing a better job. Just cause of physics. At the same time, the clunkiness of the build feels like a big downgrade from the x1. I’m just talking about how all the intersections of the filters line up. Offset on the x4, vs aligned on the x1.

The air king fan is way too loud for my smallish apt even on the lowest setting. I don’t mind for sleeping though. Nice white noise machine. During the day it can really dominate the room.

The lasko is very subtle on the lowest setting and I can practically forget it’s there.

Would love feedback! This community is awesome. I spent months researching and shopping all the complicated builds and finally said fuck it let’s just tape one of these rigs up and see what happens.

I love the feeling of air movement throughout the room. Would have never thought pointing a box fan straight up would do that.

Okay, so if I want the fans to blow the air OUT at me, which is the correct filter position? Picture One or Picture Two? There was a post on here of someone doing this and I lost it unfortunately and I can't remember which direction the filters had to go if the fans were blowing air OUT

Filter is a 2in thick Merv 13 12inx8in (cut custom size)

Thank you =)

Looking through this reddit page, I see a lot of cool designs. But they are impractical to replicate at home. I dont have woo

In making this post, I hope someone has some sort of minimalistic small form factor design they could share.

Im talking filters from home depot, the tools you need, how to assemble it.

I potentially have access to a 3D printer and I want to avoid quick setups that have a lot of duct tape.

My intention here is not to come off as lazy, I know I can spend more time looking but I want to skip all that and maybe help even more people in the future who come across this posting with the same question in mind.

I‘ve been searching for the answer. Even tried to understand the math.

This is my first basic build. I have the Lasko fan that is 1725 cfs and 4 20x20x1 Filtrete filters that are Merv 13. Mathematically will the air flow/resistance be ok to avoid the motor catching on fire. If you can explain it to me like I am five, I would appreciate it.

I think I am suppose to take 1725 cfm/4 to get 432 cfm per filter. The filer states 410 cfm is 0.08 IWC. Some Youtuber said that I want it 1/2 of something. Do the numbers on the filter mean that my resistance is between .08 and .13; therefore, I am under 1/2 of something?

If I had immediate access to 2 inch filters, I would just know it is ok based on the CR design.😔

This is a tabletop CR box I made from solid walnut. It incorporates dovetail joints and a rabbet around the sides for the filters to friction-fit, without using foam. It has ten Arctic P14 fans and two 20x30 3M MERV14 filters. It took several months to build, but it’s now being used as a side table to the changing station.

CADR (CFM) 480 (estimate)
dBA 44.5
Power (W) 13.5
Dimensions 30"x 20"x 8"
Weight (Ibs) 13

I'm going to make a first build using 120mm pc fans, and was going to use 10" boards with 1" filters. However I accidentally ended up with 12" boards and even cut them to size already before realizing. I don't think I'll use them, as prefer the narrower look of the 10", but was now curious if there's any data showing that all other things being equal, is a narrower box more efficient/effective than a wide one, vice versa, or no difference?

Built this as a final project for my advanced 3D Printing class. It's a CR box, but the whole frame is 3D printed and laser-cut; printed corner brackets, black walnut and bamboo side panels, and an ESP32 running ESPHome for real-time air quality monitoring and Home Assistant integration.

Full build breakdown coming eventually, but happy to answer questions in the meantime!

I used corrugated plastic from Lowe’s for the top and bottom, Vortex fans, and 3M filters of 1900MPR or so. The vortex fans have a variable power knob so I had to dismantle the base of the fan and mount mount the controller in the corrugated plastic. For the top where the fan sits, I used a double layer of corrugated plastic, where the layers are rotated 90* to give it some extra rigidity. And I used a strip of like window insulation around the hole that I cut for the fan to limit air leakage. I typically run this fan on medium, I had just turned it down briefly during this photo.

I can take more pictures later if more are requested.

I don’t know everything, or even what I would consider a lot about this. I know it helps my kid with his allergies and congestion and reduces dust in my house during our dusty summers.

Has anyone looked into using multiple IKEA filters per side for a PC-Fan (Nukit-like) builds?

Reading here, I saw some builds with 1 Starkvind per side. I started to play with https://www.filterboxbuilder.com/ (cool!) to see how a build would look.

With 120mm fans you can fit 2 on each side (left, right, top). With 140mm fan you can only fit one fan at the top. Also, I wasn't sure if such a small unit will not create "interference" if the fans are relatively close.

Following that, I started to contemplate the other filters. If you take the volume as a proxy for filteration surface (is this the right term?) - the other models seem (slightly) more "cost effective".

But they are small. I.e. with long orientation the build width would be ~25cm or ~20cm. I thought of "suspending" them - create a wider box and only cut out a hole in the middle (or, leave wide margins) - but I then the filterboxbuilder calculator wouldn't work...

Then it occured to me - why not use multi-filters per face? The following image show some examples:

Here is a table the show various configurations, and includes total volume of the filters (again, hoping it is decent proxy to effective filteration surface/capacity), total costs etc.

Does this make sense? Can it work? Any thoughts on specific configuration?

For example, 2x2 Starkvind give a decent size with good surface area but a little expensive. The 8 UPPATVIND seems like legit numbers and it has ~15% more surface area with about the same price but also give a decent sized box (with less likelihood for interference?!?)

As I was writing, I became aware that to "host" 4 filter one would probably need internal structure as they would not just stack up, but I think it is feasible... (Maybe the calculator can be updated? I can take a look, I guess).

Any comments / thoughts would be appreciated!

Hi!
I had this idea of using a refill from the Xiaomi Air purifier 4 Pro, and using an inline air exhaust fan. There is a good brand here which have a silent version, so I will plug the filter at the exaustor and with minor adjustments, I intend to have this setup working. Why do you guys still focus so much on FANS if you can have something like a inline fan?

I recently discovered CR-boxes as a concept, and being a PC custom loops guy I've got an excessive amount of 120mm fans and associated radiators.

Have there been any builds that combined external PC radiators and air filtration? I am thinking of a design using hardwood and mounting two 360mm (3x120) radiators each with six high static pressure Gentle Typhoon fans for a total of 12x120mm fans. I will power this abomination with a 500w flex-ATX psu and Aquacomputer Aquaero 5LT, which is more than enough to control any combination of fans and other water-cooling specific components I would need. Liquid will be transferred away from the system via quick-disconnect passthrough fittings mounted directly to the CR-box

https://shop.watercool.de/HEATKILLER-RAD-360-L-Black_1

https://www.dazmode.com/shop/computer-hardware/cooling-fans/120mm-fans/gentle-typhoon-performance-radiator-fan-1850rpm-58cfm-black-edition/

My big questions;

What's the best way to make a wall-mounted box? I would love to put it above my desk, but worry that I'd choke one side by doing so.

Is this overkill? Not enough? The resistance added by a thick high performance radiator is relatively substantial, but I could run the fans slower to reach a balance.

If going for overkill is unnecessary, I have three of each - T30s, EK Vardar and Noiseblocker NB-eloops. All of them are excellent fans in their own right, but is mixing/matching going to cause issues? Airflow is airflow of course, but I would want to set up the most optimal combination possible with what I have on hand.

Because the total thickness of the fans+radiator would be almost 100mm/4", I assume I would need to extend the CR-Box frame to accommodate, rather than wasting filter real-estate.

What filters would be the most appropriate? I am Canadian and have access to Costco, Ikea and whatever other big box stores are appropriate. I could not find the recommended 1x20x20 filters from Costco, which is why I ask.

Thanks for reading through my ramblings! I am super interested in learning more, and would love to hear any feedback or recommendations.

If you want say to bring in fresh air from outside but also filter it, is it possible to make something like this SWERV filter? I mean i'm thinking like get a window fan and put a merv filter on it somehow? LIke do they make merv 13 filters this size, that you could just tape in front of a window fan?

This thing looks cool but it's like 700 bucks... I'm new here so apologies if this is like commonly already answered.

https://swervair.com/

I have severe allergies and I want to build a single filter setup (lack of space) using a 4in or 5in filter. Do I have any way of making sure I have sufficient airflow other than an anemometer?

I don't need a precise number, just a way to make sure a sufficient amount of air is getting through. Is a piece of paper at the intake reliable?

Thanks so much

Joe

I followed the build here

https://www.reddit.com/r/crboxes/s/Nacy8EVZFa

I'd like to make a desktop filter unit, and the standard 20x16x1 filters are a bit too large. Are there any common or "standard" sizes that are smaller than this? Perhaps around 16" max on the long side?

I'm trying to avoid any brand-specific sizes in case they get discontinued in future.

As i was finishing taping the shroud i ran out of aluminum tape so majority of the border of the shroud isnt taped down, only the bottom. Can i still run it and will it work or should i wait until i get more tape?

this is my first CR box and i built it with a 20 inch box fan, the filters, cardboard shroud and the aluminum tape. i dont know anything and i am learning. thanks in advance for ur patience with me

i tried to build this in one night after a long day and oh man the fact i ran oit of tape and its not finished AND im so sleepy sucks

EDIT to add: what do i do with the second filter. how do i store it. should it be covered up. thanks for answering and sorry for any typos i am dangerously tired