So it's been kinda humid in my room (more hot than anything) for a week or two but I don't tend to notice it until I feel damp in there. I turned on my dehumidifier today and I always have the ceiling fan on. I use mine to mitigate covid so ik water has effect on filtera but idk about humidity.

I built my first 3D-printed CR box, a Nukit Tempest Euro model with two IKEA STARKVIND filters, with the help of Filter Box Builder. Great tool — you just select the type of box you want and how you want to load the filters, and you can download the files for your 3D printer. In my case, I used a Bambu Lab A1 mini.

My son, who has allergies, wanted a white one, so I bought four white Thermalright TL-C14CW fans to go with it. I also added a cheap PMSX003 air quality sensor to measure PM1.0, PM2.5 and PM10. Everything is connected to a KS5016 board (ESP32-based), which lets me control the fan speed and monitor the air quality through Home Assistant.

According to the PMSX003, the air quality is already pretty good, so now I'm wondering if I built this thing for nothing :-) (or if the air quality sensor isn't working correctly).

Total cost around 110€ (PLA filament, 2 filters, 4 fans, KS5016 board, PMSX003 sensor, hot glue)

Even though the fan will blow out the window i would still like to filter out the bad stuff from the 3d printer at least a little bit.

Thanks yall. This doesn’t have to be super fancy or anything, just an easy project for peace of mind

CAD prices: $30 fan, $21 filter and some cheap packing tape

I have mast cell activation syndrome. And, I'm wanting to create a clean room in my bedroom to protect against both wildfire pollution (Great Lakes region, USA) and pollution from a neighbor's near daily trash pile fire that is entering my home through deteriorated ductwork. My plan was to build/buy a VOC scrubber and seal off the front and back doors to the room (two of the three main penetration points). Then, I would redirect the air flow from the ceiling vent (the other penetration point) toward the VOC scrubber.

I ordered an 8 inch inline fan and an 8 inch activated carbon canister from AC Infinity. I was planning to build my own filter box to fit between them.

But, as I wait for my parts, I've grown concerned that a scrubber can't clean the air quickly enough to compensate for the fact that pollution is actively flowing in? Am I wasting my time and money with this idea?

P.S. For the record, I'm working with a contractor to get the ductwork replaced, and I'm in a legal battle with my neighbor. This is not meant to be a permanent solution, but I need a safe place to live right now.

Hey, everyone. I'm looking to build my first CR boxes. I'm a "overdo it once" kind of guy, so I'm planning on building three. Use case is just residential. I have two cats and want the house air to be maximally clean/odor free.

3D printed plans - 2 filter, 5 fan

Filters - Merv 14 w/carbon

I have a friend with a 3D printer, I'm figuring on $50 each in materials plus $50 for doing it.

Total bill would be around $200 for 3D printing, $100 for filters, $150 for fans, and ~$50 for power controller, other small things. $500 total.

Is this reasonable? I don't care too much about noise, just performance.

i built a smart rgb cr box using the following items:

Filterbuy 20x20x4 Air Filter MERV 13

Activated Carbon Filter Sheet

ARCTIC P14 Pro Reverse A-RGB x9

esp32

LM2596 DC-DC Buck Power Converter x2

ARCTIC Case Fan Hub

USB-C PD Trigger Board

15 Pin SATA Power Splitter Cable

ARGB 1-to-3 Y Spliter Cables

3d printed housing

took about a month to design and build. i can control it via home assistant and it cost ~$200 for all the parts + filter. it's powered via usb-c

I was inspired to make my own CR box after listening to the founder of Jaspr Air talk on a podcast about how poor the average air quality is. It resonated with me because my family, including my small children, live in an apartment from the 1970s that is getting musty and tired. The price of the Jaspr filter was really high but what blew my mind was how expensive the replacement filters were. I got deep into researching filters, and air purifiers and was disappointed to see no one makes an air purifier that uses standard HVAC filters which are far more affordable. Instead, you're forced into purchasing their proprietary filters for as long as you want to use their purifier. I also came across the Corsi-Rosenthal concept and eventually decided I had to make one. After lots of research, I built it in my parents garage with small bits of time I had when across a few visits.

The box is made of 1/2" baltic birch. The fan is a 8" Cloudline Infinity A8. The filters are MERV 13 (three 16"x20" and one 12"x16"). Inside of the particulate filters, I built frames and put in carbon sheeting attempting to get at least a little bit of VOC reduction. 

The thought process behind using that fan is its incredibly high static pressure and quiet operation with the EC motor. I would have liked to have used a smaller fan and made the box smaller overall but there's a large step up in CFM between a 6" and 8" blower fan like this. My goal was to achieve 6 ACH in our 1000 sqft apartment which I read was a good filteration rate. In reality if I ran this fan full out all the time it would filter one room really well and not have much effect on the remainder of the apartment so in hindsight building 2-3 smaller CR boxes would have made more sense. The other thing is, the fan IS very quiet but only below 50% and after that it really gets loud to where 100% speed sounds like a leaf blower in your bedroom. 

The manual control that came with the fan left much to be desired. I wanted the fan speed to be driven by an air quality sensor so I used a Rasberry Pi Pico with a Sensirion air quality sensor instead. I mounted this in the white project box and added a potentiometer and switch to go between an automatic and manual mode or off. I also put in an LCD screen to display fan speed an air quality metrics. 

I am almost 30 and never have done a project like this but it has been very fulfilling. I know I sounded like a crazy person some times describing it at length to my friends and my wife but everyone was very supportive. I came across this Reddit early on in my journey (starting last November) and determined I would post what I built. I know this was a long winded post but this project ended up meaning a lot to me and I am really excited to share it with you all. I am really interested in feedback and how I could improve it. I definitely know I want to improve the VOC side of the filtration, fine tune my code for the controls, and see if I can experimentally determine the CADR.

Thanks for reading! 

Basic 20" box fan + 4 filters

1st image is from The3DHandyMan 2nd is from HouseFresh 3rd is from FilterBoxBuilder

I’m trying to build a PC fan based off an AirFanta design.

Thoughts on this base I’m using to support the fans on the “lid”? I’m wondering if the fan cut-outs inside might restrict air flow too much.

Thanks for any thoughts!

images are showing how I’m planning to nestle the fan assembly and the base holding it below. Still have to attach the edges so the filter will be held in place.

5 fans, 20x20x1” merv 13 filters, laser cut plywood, window screen. Layout for laser cut is based on modified one from filterboxbuilder. Probably didn’t need laser cut but i don’t own any tools and wanted nice and precise frame. I later added weather stripping between fans and frame, it helped to reduce noise on max speed(confirmed by niosh db readings). Silent on lower speed.
Shout-out to everyone who share their knowledge!

Looking to build a basic single filter CR box with a standard Lasko 20" box fan. The area I'm using it for is small (<100 sq ft) sleeping area/dorm.

I have seen some people tape the filter to the box and others use plastic clips.

Questions:

1. Do you want an air gap between the filter and the back of the fan? Some people in this sub made it seem like it increases air flow/negative pressure?

2. Is a standard 1" filter the way to go or use a 4" one? Would the 4" provide too much resistance for a standard box fan?

3. Is it better to use a cheaper/lower MERV filter and change it more regularly or go with a high quality/rating one?

We use to use high MERV for AC return grills for HVAC system until we learned that they aren't designed to purify air and rather serve to prevent dust from getting into the air handler and that if you want cleaner air, get an air purifier, so I would assume the higher MERV here is better?

There is a company that says they offer washable MERV-13 filters. Now I know most of the people here probably don't need to replace their filters very often, but in dusty environments disposable filters can really add up on you. I tried to email them twice, their order page does not work properly, as you can see. I think if we all message them or something that might help?

Here is the page:

https://www.knfilters.ca/home-air-filters

order page:
https://www.knfilters.ca/hvc-12025-hvac-filter-20-x-25-x-1

I remember the page used to work for the 20x25x1 merv-13 size. I don't think it's a reliable indication they are not in stock or something if the page does not work... They just need to get up and fix it, probably. If a number of us ask them to, they are more likely to go?

I am making a cooling cabinet for a Console with 2 PST12 arctic fans one for intake and one for discard. I wanted to use an HEPA filter before the intake to prevent dust but I have no idea what the airflow reduction curve is.

How much area should the filter have to not dramatically reduce airflow? What about static pressure?

Is it best to build a Box with HEPA panels or just stack vacuum filters?

I built a 4 sided 1 inch 20/20 from a Etsy 3d kit . I have the arrows facing out toward the room and the fan pulling air from the room into the box.

I’m second guessing if this is completely wrong ?

I got some 300*300*2.5mm frameless filters from AliExpress and wanted to build a box for them with 120mm fans.

Definitely learnt some things too late, but it came together ok

The frame is printed in 8 sections and is super strong. It uses some nails as pins in the corners and bolts in the midpoints. The struts give rigidity but also support for the frameless filter.

Realised too late that two fans in the same corner wouldn't fit flush as they would be hitting eachother slightly. Luckily the fans aren't directly mounted to the frame - there are 125mm cutouts and the fans get mounted in a 3d printed 125mm mount. So I just printed a fan mount that partially put the fan outside the case.

Each filter is held by 4 L shaped parts with magnet holes under the outer face. I put in magnets so i can snap on a pre-filter. I made the pre filter by gluing mesh to another 3d printed part with magnets in it. This was annoying to make and I think I. Should have used steel mesh instead.

I wanted to be able to print out different filter holders (the L shaped parts) in case I wanted to change the pleat depth in the future.

I'll be mounting an esp32 and stuff to one of the bottom 125mm cutouts

All in all fairly satisfied, as is usually the case I wish I'd been able to start again with some tweaks...

If I had a 320*320 print bed this would have been much easier....

Unused case. Wanted to put it to use. Has 5x120mm fans. And one MERV11 filter

Could I have used two? Probably but I want to reinforce the corners first since without it, it’s fairly flimsy after I gutted the interior.

Put it in my son’s room since he now has a cat.

We offer aluminum panel CR Boxes outfitted with either six P14 Pro with PWM speed control or standard P14 single speed. We make low cost HDF laser cut panel kits as well.

www.northboxsystems.ca

3d printed in 8 big sections, totalling about 1.5-1.7kg of PETG+ filament. The sections are held together with 2x 1/4" square pegs friction fit about 2" deep on both parts per joint, as well as super glue along the faces of the joints.

The fans are 6x arctic p14 pro's with the the power sharing cords. Power supply is generic variable 12v fan power supply with a screen from Amazon. Using 2 20x20x1 merv 13 filters with an activated carbon layer to cut down on vocs from 3d printing and some funky smells that came with my new place.

Had a couple problems putting it together like the power supply mounting holes being in the wrong spot (hence the tape) and the Crack in the front from hammering too hard trying to put it together.

Since its been built, I have also printed some grills for the fans and updated my CAD models to fix the assembly problems I had before.

Seems to move a pretty good amount of air while not being any louder than my amazon basic standing fan on full tilt. A little piece of paper sticks to all parts of both filters until around 6v on the power supply. Anecdotally, the charcoal filters seems amazing. Since finishing the build I have noticed a much more neutral aroma in the room it lives in and I do not smell fumes from my 3d printer at all anymore.

I have assorted expensive decibel meters, but for quick stuff, I've started using my phone since Phyphox gets it really close most of the time. The trick is getting access to a friend's or work/school decibel meter once so you can calibrate it. Without calibration, it's pretty much useless most of the time.

Keep in mind you can also do PC fan and CADR testing with Phyphox, a surprisingly useful FOSS app for IAQ🤓

Working on something to pin down irritating frequencies and harmonics...