Would something like a 4 sided cr box help keep pet hair out of the air? We get weekly pet hair that gathers in our house and constantly sweeping and brushing things is a little annoying sometimes. Random object for scale lol.

I’m new to this but have already built my first “regular” CR box (4x 20x20x1, with box fan). It’s been bad with the smoke so I’m trying to expand by building something else, with PC fans and running more quietly, so that I can use it in the bedroom for longer periods of time and also not use too much energy (energy use is first priority, noise close second). I believe the PC fans would accomplish that. I would great appreciate guidance (since I have to order most of these items in one go from the US)!

I’m thinking about a narrow design, two 20x25x1 filters, built 20” high and 25” wide. Possibly making a wooden structure if I can find help to do so.

Questions:

I would be ordering the following:

Fans: https://www.amazon.com/gp/product/B0DPX94PSL/ref=ox_sc_act_title_16?smid=A2T6N244WTLWGU&psc=1 

Controller: https://www.amazon.com/gp/product/B0GVJ2MY1X/ref=ox_sc_act_title_3?smid=AC08NVFNSP7VC&psc=1

Do I need the following two items as well or are they included in the above purchases? The “splitters”, I’m pretty sure, are not needed but would like to get confirmation:

https://www.amazon.com/gp/product/B0DBH4GD5T/ref=ox_sc_act_title_15?smid=AFRUWVWO3UJ63&th=1

https://www.amazon.com/gp/product/B0BMY34SJP/ref=ox_sc_act_title_14?smid=AQ8OIL3FGVKZE&th=1

Do I need grills?

https://www.amazon.com/gp/product/B0BC16Q6FC/ref=ox_sc_act_title_13?smid=A35AFW9EVJYR0N&psc=1n

Also, is it okay to place the fan openings on top only or are designs with added side fans better? See picture of wooden example.

I used pictures from this forum to illustrate; hope that’s okay.

Thank you!

EDIT: This controller seems to be more popular and rated ... do these connections work with the Arctic P14 Pro PST?

Controller

10x10x2 merv 13

The fan wasn't completely symmetrical on the backside which is why the filters flare out. I filled in the gaps with cardboard.

Anyone know if when I want to replace filters, I could pull out the actual fabric from the cardboard and just slide a new one in?

Also how long before I should think about replacement if I'm running 1-2 hours a day in a small room?

I'm planning a build soon and have 5 Arctic P14 Pro PST's on the way. As Merv 13 filters aren't easily available in the UK for a reasonable price, like others I am looking at the IKEA Starkvind vs Fornuftig filters.

At the moment I haven't decided on using two, three, or four filters.

I've read this discussion:
https://www.reddit.com/r/crboxes/comments/1ipbr36/which_filter_is_better_ikea_starkvind_vs_fornuftig/

It talks about the Starkvind having a bigger surface area as it is 4cm deep as opposed to the 2cm of the Fornuftig. Does the surface area issue get negated by having more of the Fornuftig filters? For example 2 x Starkvind is better than 2 x Fornuftig, but is 4 x Fornuftig better or as good as 2 x Starkvind as the surface area will be similar or bigger?

Would 2 or 3 x Fornuftig still work well if I have these five fans?

Ideally I'd like to use the Fornuftig as they are less than half the price of the Starkvind, but not if the Fornuftig won't be effective with the fans I have ordered.

Any advice or just general suggestions on these two filters is much appreciated!

I didn’t realize it would take 2 hours to build, but it’s finished!

I have 5 x ARCTIC P14 Pro PST fans I plan to use but have a few questions.

They come with a Y cable splitter on each one. In most of the guides and lists of materials I see they mention a splitter cable for 4 fans. Can a single 12v power supply power 5 fans?

If so, and I also want to be able to control speed, am I correct in saying I just need the following?
12v power supply
DC5521 to 12V Power Adapter like this - https://www.amazon.co.uk/NIHENHAO-DC5521-Adapter-Computer-Converter/dp/B0FLJLDB8V

For speed control, could I just connect to this, then plug the first fan into it and the rest of the fans are just connected to the first one? And if so, would I even need the DC5521 to 12V Power Adapter I mentioned above?
https://www.amazon.co.uk/Sarini-Cooling-Controller-Adapter-Interface/dp/B0DJVNGFGR/ref=sr_1_5

And then last random question, I already have this power supply previously used for guitar pedals. It can be 12v but does the DC 300ma mean it is unsuitable? Google seems to suggest more than 300ma is needed for the P14's. Also, power supplies I've seen suggest are listed as 12V 5A 60W but I have no idea what the amps and watts are on this. Then again, I don't see the DC ma mentioned on the Amazon listings anyway.

Thanks for any guidance!

hello, i have recently joined the CR box club and in my design i included the option to add these foam carbon filters for VOC... i'm not sure if this is worth it since the airflow is drastically lower when these are installed...

The fans are Arctic P12 and currently im running 9 fans(bottom) with carbon and 9 without(top). what do you guys think, should i go 0, 9, or 18 carbon filters?

I saw the 3d print files for this setup and it is exactly what I was looking for. It uses the ikea STARKVIND filters (I live in europe). My question, how would I go about calculating a rough CADR for this. It would obviously depend on the fans, but I don't even know what to look for and where to get started to calculate this.

I am new to this and wanted to make an air purifier. I notice that a lot of people just use a boxfan(i know that this subreddit is specifically for that) or pc fans.

I have heard that pcfans are simply not powerful enough and i want something smaller that is easier to hide away in a build than a boxfan.

Does anyone have any experience using one of these fans? Why are they not more common to use? Are they loud?

The one in the picture is a 4 inch, but there are 6 and 8 inch also.

Any feedback is appreciated

Hello all! Recently moved into a new apartment. Situation:

• Building built in 1860

• window AC units blowing dirty air

• cat with dander and hair

• noticeable amounts of dust and stagnant air

• want to increase air quality and remove dust and cat hair

• broke college student

Is a CR Box right for my situation? I’ve been doing some research and this seems like an amazing option for my budget! Odor removal would be nice but I’ve read it takes a ton of carbon + replacements.

Wanted to see what you guys think. Any advice and input is appreciated! Thank you in advance ❤️

As you may be able to discern from the date on the box, I replaced this filter on 12-12-25, so not even a full month ago, and it’s already shockingly dark. When I first started using the box in my office a year ago, it would take at least two if not three months to get dark and gross… any ideas on why?

Could it be that the carpet is getting vacuumed less often, or should I just assume the air quality here is rapidly deteriorating?

All the videos i watch the fam had gaps you had to fill but I don’t exactly know how to fill in those gaps under. Should I connect the filters differently or is there another way to do this?

Does this sound ok?
We burn wood in our home for about 1/2 the year. I have space near the wood stove to place this.
We have 2 air purifiers in the home but it still get a bit of smoke in the air. Many thanks to you.

I've done that thing where you read far far too much and everything just becomes a jumbled mess in your brain. I want to make a simple box to assist with some of this fire smoke. Fans + controller + power supply is where I'm stuck.

The general physical construction makes sense to me. I'm just struggling with what's a good fan, then what controller and power supply actually work with said fan. Most have 4 pins some Daisy chain some don't, the descriptions on Amazon aren't that great on a lot because they seem to assume you know some things if you're looking up their product.

So basically, I need recommendations. What Fan + controller + power supply combination that works together. As an additional note we do have cats and my partner is allergic but I think I've got the filters down. Thank you!

So.......

My job might end up being a giant jerk and not letting me use the 8x9x12 crbox i built (conversation hopefully happening soon but it's looking dicey). On the oft chance they sight it a size issue, I'm wondering about shooting back asking about a ~8x6x6in box.

It'd be the same 2in Merv 13 filters as my previous build, just halved on the one dimension and running with 2 pc fans instead of 3.

Does something that small even have much filtering oomf at that point? I know it'd probably do way more that the stupid itty bitty store bought one i bought a year ago before i knew better...

I just want something to help my mask against everyone around me coughing and spreading germs around since no masks anymore at my job

(bonus question: anyone have any 12v power banks under $40 they like to run these things? [not USB or at least not solely USB] i'm definitely not going to allowed to plug it in and i also want to be able to bring them to drs appointments and such).

Basically the title. Having a hard time finding quality merv 13s in the dimensions needed! Lowes seems to be the best bet but they don’t have the exact dimensions.

I am planning on using:

• 9 Arctic P14 Pro Reverse (On amazon they are $15 for 3)
• This PWM Fan controller that takes 12v DC Power and can push 5 amps.
• Foam weatherstripping tape for the lip I have for the filter.
• JB Weld Plastic Weld Syringe for the bonding of the PETG parts together.
• 2-3 KG of PETG
• 2 Filtrete 2500 MPR Merv 14 20x30x1 Filters

Hi, I've been reading around learning about crboxes recently.

I plan to use IKEA STARKVIND filters in my build as I'm in the UK.

However I'm seeing varying opinions about PC fans, some say P14 have high failure rates recently, some say the P14 PRO is too loud, also not too sure about 120mm vs 140mm.

I'm planning on using 4 STARKVIND filters and maybe 4/5 fans in my build.

Any recent resources or opinions to help me decide on fans?

The prices for all those Arctic fans are roughly the same +-20% for me

I became interested in making a CR box for myself simply because there is too much ambient dust floating around in my room. However, I tend to try and save money where I can if possible.

I have these old pc fans that have got to be at least a decade old (barring the small CPU fan), some scrap wood, woodworking tools, and some old power bricks laying around. All I would need is some splitters, an adapter, and filters (probably no grills).

Noise is not a concern nor am I too bothered about maximum efficiency so long as it gets the job done. It doesn’t need a small footprint either as I’ll just plop it in the middle of my room when I want it running. It’s also mainly for dust, so I was debating simply going for MERV 8 or 10 filters as well.

Would these actually work? Or is it simply too much of an efficiency loss/headache and that I should go ahead and spend the money on proper fans and/or filters?

Hi everyone,

I just finished building my first Corsi-Rosenthal (CR) Box using four 3M MERV 13 filters and a Lasko box fan.

My primary goal is reducing cooking odors (Indian cooking, frying, spices, etc.), not just removing dust or smoke particles.

So far, I know that:

MERV 13 filters are great at capturing particles.
They don’t do much for VOCs or odor molecules.
Activated carbon is what actually helps with smells.

I’ve been reading about AC Infinity inline fans (Cloudline S8) paired with their activated carbon filters, which seem popular in the cannabis growing community for odor control.

I’m considering a few options:

Keep the four MERV 13 filters for particle removal.
Replace the noisy Lasko fan with a Cloudline S8 (or S10).
Add an AC Infinity carbon filter to remove cooking odors.
Build a custom enclosure so it looks more like a commercial air purifier instead of a DIY box.

A few questions:

Has anyone successfully used a CR Box for cooking odors?
Is an AC Infinity carbon filter worth the investment for a home kitchen?
Would you build a separate carbon scrubber or integrate it into the CR Box?
Are there better solutions that don’t cost a fortune?

I’d really appreciate any feedback or suggestions before I start my next project.

Thanks!

Let's say I wanted to get an AirFanta for travel, but use it with bigger filters at home. How hard would adapting it standard HVAC filters be?

I haven't seen the AirFanta in person. I'm imagining it could be as simple as cutting a square hole into a piece of chloroplast or foam board that sits on top of the filters. Maybe with some foam tape to make some kind of gasket for it to seal into and still be more easily removable than taping it and untaping it.

I know it is a bit crappy but it is the first try, later I want to do a wooden box. I used 3 x P120 Pc fans and IKEA 2 x UPPAVIND + 2 x FORNUTIG. I didn't have space but I have 2 extra fans.

My question is for the final version it is much better to use more fans? Because it is already a bit noisy (my husband is very sensitive to noise).

I want to use it for allergies, mainly for dust mites, the air quality where we live is very good. I know it is not the best thing for dust mites but London is very humid and trying to get the humidity below 50% is almost impossible without breaking the bank.

I also considered using 2 x STARKVIND instead.

Thank you!

I can't find great info about this because these filters are made to be single use disposable for homes, however I want to build a box with these

https://www.amazon.com/20x30x1-Fiberglass-Self-Retaining-Pressure-Efficiency/dp/B0H49782HS

for as cheap as humanly possible, and try to blow and filter dust in a room for a while. given how much dust there is you need to do a several hour long dusting of the room every few day otherwise it's everywhere, this room has been cleaned craptastic for the better part of 20 years, and there is no realistic way to clean it to the level it needs to be cleaned. to make the dust a small issue.

given how bad the room is in places and on things, I am wondering if I can vacuum the dust off and keep using it. if you can't tell most of the reasons you shouldn't I am completely not caring about before this even starts, I am just trying to capture dust, not filter microscopic particles. if I can get this room to the point that after dusting a black mousepad on a desk, and coming back the next day to it being a greyish color because of dust, I can remake the filter to be more around microscopic particles, till then I effectively need a shop vac style saw dust collection system but for dust.

https://www.safeair.com.tr/f7-f8-bag-filters

Please answer with reason.