CleanAirKits - Brisk Box Kit

Corsi box is where it's at. Ours is with 2'x4' filters. Sits in the foyer with high 2nd story ceilings and open to formal living, dining, and kitchen (easily 2k+ sqft), been on 24-7 for 4 years.

My wife built two of these for our house. She despises dust. They work pretty well.

One is in the front door foyer to blow up the stairs. The other is in the living room. We have a dog that sheds a lot and that's where he spends much of his day.

Corsi-Rosenthal boxes are what they're called! I have a lot of allergies and I use one of those. They're great.

A [CR box](https://corsirosenthalfoundation.org/instructions/) (Filtrate 1900 or MERV 13 furnace filters and a box fan) is your best option: they're cheaper and more efficient than commercial air filters; because the filters are just furnace filters, you can get them basically anywhere; and they can be designed in lots of ways to suit your space (the standard 4-filter design, two filters in a triangle shape with the fan as the third side, one filter with a spacer between the fan and filter, two or four filters with computer fans for quieter filtration, mounted to a wall like a floating shelf, etc). Look online for pictures and further instructions for different shapes.

Thirding air purifiers! I finally gave in and traded my two big winix HEPA guys for a gigantic corsi rosenthal box made of four 20x20x4-in home AC filters. It's much louder but the performance is out of this world, and the filters last forever now. My two 1,200sq ft rated filters struggled in my 500sq ft space with even monthly changes (desert life, lots of animals, massive grading project nearby, endless dust), but this one box handles it no problem, and for many months now.

Corsi Rosenthal box. Fuck proprietary (and often expensive) filters. Mine are from Clean Air Kits and they are stupid quiet, I can run them off a battery pack in case of power outages cause they are super cheap in terms of power usage and I can get furnace filters cheap. We have two dogs (one of whom has nasty allergies to pollen) and they make a huge difference. We have one per floor but make sure they are sized for your space.

You can make a Corsi Rosenthal air filter. Check out the instructions on youtube. They work as well as industrial air filters.

I made it, just crudely taping some whole house filters onto a box fan. It won't be fun to tape up again when I need to replace the filters, I need to create a proper design that's easily maintained, but this was a proof of concept. It's been several months and it works perfectly.

Look up corsi-rosenthal boxes. I just built one last week and I'm way happier with it than my levoit.

If you don't have an air purifier you can make a corsi rosenthal box for cheap. Or you can make a more efficient one using pc fans (we have one of those. They are super quiet, super cheap to run and the filters only need to be changed every 6 months or so. Plus we can get them for cheap when they go on sale). It makes a load of difference in air quality.

Not pretty but very effective Corsi-Rosenthal Box - Wikipedia https://share.google/VT90TcVB763kaVmSa

I built a Corsi-Rosenthal box for $60. It doesn't look pretty but it works really well for our small house at that price range.

Depending on where you are you can spend way less and get good stuff. It really depends on how dirty the air is and how clean you want it. **H**(igh)**E**(fficiency)**P**(articulate)**A**(ir) filters are good because they capture more particles than others. Below them are MERV filters rated 1-16, and [as you can see here](https://www.epa.gov/indoor-air-quality-iaq/what-merv-rating) anything less than 12 nabs under 80% of PM2.5 and imo isn't worth it. These are also more common in home HVAC from what I've seen as well - for mobile units, it's either HEPA or "HEPA-type" which means nothing. If you want the most efficient unit and to spend next to no money, [Corsi-Rosenthal boxes](https://corsirosenthalfoundation.org/instructions/) are the way to go - you need to be able to build and rebuild them, and tolerate a decent amount of noise though. Otherwise, the size of your rooms matters. BlueAir, Coway, Honeywell, Lasko/GermGuardian, Levoit, and Smart Air are some brands that are reputable and have a range of units and sizes. Keep in mind most purifier marketing advertises performance on only the **highest** setting, while advertising noise on the **lowest** setting. Most makers do not have data on other settings, though there are rare exceptions [like Medify](https://medifyair.com/collections/air-purifiers/products/medify-ma-40?variant=39663322628163).

Cleanairkits.com uses the CR box inspiration but way quieter and super easy to replace the filters (MERV13). They have all their cadre, glow, decibel stats for each model. I have been using them for years now and love them!

nobody has thrown it out there so I'll mention a corsi-rosenthal box. I made one last year and while I don't have a regular air purifier to compare against, I think it's been doing a pretty good job. The filters were disgusting after 6 months, anyway, which I doubt would be the case if it wasn't pulling in quite a bit of junk from the air. might be worth a shot, especially with how bad the air quality is rn

Have you considered making your own? https://en.m.wikipedia.org/wiki/Corsi%E2%80%93Rosenthal_Box I know some people are hesitant because of the looks. But I've been using this design since COVID and I can't be happier. The box fan was $20 and the filters are $40 every couple of months. They're inexpensive and you can use any size filter you like. So the only real downside is the aesthetics are not what a lot of people are looking for. But it works pretty dang good with the right filter.

Three words. Corsi Rosenthal Box.

Corsi-Rosenthal box. Many people love them on this sub, if done right. They're great! Although I believe you'll want a MERV-13 at a minimum. :)

Yeah absolutely. I don't mind a little noise, but on some of these air purifiers to get the CADR that makes sense, you need to blast them. I recently bought a PC fan air purifier from clean air kits. They t won't win any beauty contests but it moves a tremendous amount of air with very little noise.

If you're looking to collect dust - you should make a Corsi-Rosenthal box. A HEPA isn't going to process enough air for really getting rid of dust. If you don't want to make one yourself, or want a nicer aesthetic, check out Clean Air Kit. Here's an [informative video](https://youtu.be/gaQTYrisieA?si=mjj8lAmHywe_exSu) on this topic.

I have the same unit next to my PC for a small area. The CR Box is still far better. I use one in my main rooms and just put them away when people come over. https://youtu.be/RjN205kkwoY?si=xApI8CX4mZ1Ilffj

They are super quiet. Some people can sleep with it in their bedroom (I'm not used to white noise/airflow like a fan so I couldn't get used to it). Takes like 10-15 mins to tape the filters into a box but if it's like once a year it's no biggie compared to performance (CADR) compared to the noise. Maybe have one per floor if you have someone with allergies or live with wildfires or something. I really like mine.

My setup is similar! I use my Ikea Vindstyrka and a Sonoff wall outlet to control my Corsi-Rosenthal Box (https://engineering.ucdavis.edu/news/science-action-how-build-corsi-rosenthal-box). The fan is set to low because it works very well with minimum noise. I initially built the filter box to manage dust during my snail-paced DIY remodel, which also includes a major project to fully monitor and automate my home. I got the Vindstyrka to monitor the interior air when I got a weather station to monitor the exterior. Added the automation soon after as one of my first HA automations. I may eventually upgrade the sensor and purifier, though I'm beyond impressed with how well this extremely basic system works for a total investment of under US$150.

First off, "best" is whatever has the highest CFM rating. Whatever pushes the most air is pretty much best. Corsi Rosenthal boxes are "best" as they can easily push 1000 CFM. But in reality you choose based on other metrics, such as price range, availability of filters, price of filters, how often they have to be changed, how quiet they are and so on. I picked a Philips 4200 Pureprotect, to me this was best, as it was high CFM rating, auto setting and very quiet. While also having new filters available in my market for years to come. And personally I've tested it at home, where I don't notice much of a difference as air qualiy was pretty good in the first place. But also in the homes of friends who have dogs and I have asthma and react to them. Had a friend set it up a few days before his birthday so the air would be properly cleaned for a few days when I got there and it made a huge difference. Usually I notice symptoms after just a few minutes, this time I could spend hours at his house with minimal symptoms. But even if my unit is a quite expensive, good and quiet unit it still doesn't get close to the Corsi Rosenthal DIY boxes in terms of how much air is purified. Hope this helps, just keep filter price and exchange rate as well as availability in mind when you buy one and you'll be fine. And remember more air is better, filtration efficiency matters a lot less than just the air volume.

You want the brisk box with pre-assembled 6 fan kit https://www.cleanairkits.com/products/brisk-box?variant=47660329173292 Most they go on discount is like 10-15% like twice a year. I have mine (3) hooked up to smart outlets so I can turn them all on or off when I open windows, but usually they are running 24/7. I get my 3M filters at costco when they are on sale. Has been like 10 months on one filter just fine.

How often do you cycle it on and off? I have a diy corsi-rosenthal box that I just run 24/7 on low

Unfortunately that website has been completely taken over by affiliate link BS. 95% of air purifiers sold online are complete garbage. Have tried many over the last 15 years due to asthma and allergies. The only cost effective solution I found that actually works (have an air things air quality monitor so I can tell by turning on and off air purifiers) is a box using home furnace fan filters. I got one from clean air kits that uses computer fans and it's super quiet so you can sleep with it on. Mine is 4x 20*25" filters. You can make your own with box fans but they will be crazy loud. The 4 fan one is good for a small room. https://www.cleanairkits.com/?ref=ANNALE&gad_source=1&gad_campaignid=22709004639&gbraid=0AAAAA_ODbriF_jyz8Gjm983QOPyONyoIt&gclid=CjwKCAjwt-_FBhBzEiwA7QEqyI5KZ5R9_7eGZZIs3i8JuZzTyN3fsBU8lDCdZe9VxwvN-gMl4hPouhoCCpMQAvD_BwE And you don't need the most expensive filters either, in fact they work better with the mid range ratings as they have way more airflow. Mine are 10s or 11s I think...

Corsi-Rosenthal box. You can make one yourself, or buy the kits. The ones with computer fans are wood or metal and will last forever, and because it uses MERV-13 furnace fans you only have to replace them every few years.

A commercial air purifier that meets all your criteria and actually works as effectively as you want it to will be well over $300. Under $300 you only have two realistic options: build yourself a Corsi-Rosenthal box with computer fans, or buy a Corsi-Rosenthal kit. A CR box with computer fans is going to be quieter than any commercial air purifier, and the filters will be cheaper because they're standard filters you can buy at any hardware store instead of proprietary filters you can only buy from one company, and by design CR boxes are super easy to maintain. CleanAirKits in the US, NorthBox in Canada, and Nukit in China all sell CR box kits with computer fans. The most BIFL option out of these is Nukit, made with steel, while the others are made with wood or acrylic. I have severe allergies myself and I have two CR boxes, a large one I built myself at home, and a small portable one from CleanAirKits for my office or wherever else I might need it. They've made a big difference in my allergy symptoms. Check out the Nukit Tempest mk 2 when it releases later this year, it is planned to have all the features you listed. The other thing with allergies that often gets overlooked is cleaning. Especially if you have pets you are allergic to, you should dust and vacuum your house two or three times a week. Air purifiers alone won't be enough.

They work. Most are over priced though and the filters cost an arm and a leg and are where the profit is at. Most people could get away with a Corsi-Rosenthal Box, connected to a smart plug and turn it on when they cook for a drastic improvement in indoor air quality for cheap.

>I've done some research online There is a rabbit hole to go down comparing filter single pass capture-rates and clean air delivery rates. It is possible that a couple of [DIY Corsi-Rosenthal boxes](https://www.webmd.com/allergies/corsi-rosenthal-box) will be more effective, or more cost-effective, than a commercial HEPA filter. Especially for use while doing renovations that generate dust, Where we live, there are days when the AQI gets up to "Health alert: The risk of health effects is increased for everyone." and it is sometimes at "...members of sensitive groups may experience more serious health effects." for multiple days. We just replaced one of our Blueair air purifiers (under warranty). The replacement has a particulate counter that controls the motor when set to "auto". When we fry something on the stove-top -- two rooms and two closed doors away -- it sounds like it is trying to get up to airspeed. I know the Blueair makes difference in the way things *smell* on days when the air outside is purple, so it is not completely ineffective. OTOH, the two Blueair purifiers are on all the time and we have ***not*** noticed a decrease in the rate at which dust accumulates on the woodwork in the house. I've thought of getting an air-quality monitor to try to quantify the efficacy of the Blueair purifiers, but I am not sure what I would do with the information. I've got two double-tall Corsi-Rosenthal filters -- one in the Attic and one in the basement -- that I run when the air gets really bad or when I know I am going to be working in one of those spaces for a long time. The C-R boxes move a lot of air, and do really cut down on the big-enough-to-see dust circulating in the air and piling up on surfaces. * Eykelbosh, A. Do-it-yourself (DIY) air cleaners: Evidence on effectiveness and considerations for safe operation. Vancouver, BC: National Collaborating Centre for Environmental Health. 2023 Jan. [https://ncceh.ca/resources/evidence-reviews/do-it-yourself-diy-air-cleaners-evidence-effectiveness-and](https://ncceh.ca/resources/evidence-reviews/do-it-yourself-diy-air-cleaners-evidence-effectiveness-and) * Stephens B, Siegel JA. Ultrafine particle removal by residential heating, ventilating, and air-conditioning filters. Indoor Air. 2013 Dec;23(6):488-97. doi: 10.1111/ina.12045. Epub 2013 May 13. PMID: 23590456. [https://onlinelibrary.wiley.com/doi/10.1111/ina.12045](https://onlinelibrary.wiley.com/doi/10.1111/ina.12045) * Ratliff, K., & Gov. (2023). *Homeland Security Research EPA ORD's Corsi-Rosenthal Box Bioaerosol Testing Results*. Retrieved February 15, 2025, from [https://today.uconn.edu/wp-content/uploads/2023/10/EPA-ORD-CR-Box-Bioaerosol-Results-embargoed-10-30-23-11am-est.pdf](https://today.uconn.edu/wp-content/uploads/2023/10/EPA-ORD-CR-Box-Bioaerosol-Results-embargoed-10-30-23-11am-est.pdf)

Yeah, as long as you're cool with how ugly it might look, and also cool with rebuilding it at least twice a year, the price performance ratio basically only gets beaten by commercial options. It's also certainly not buy it for life, but I think it's always worth bringing up regardless just because of how easy and cheap and good it is, it's way better than buying a fancy one and risking it taking a shit in two years.

They work very well. When covid hit i looked for a way to try and address aerosol transmission as someone who has never caught a light cold or had a touch of the flu in my life. If i get sick i get very sick. I put together 2 of these and bought a CO2 and a particulate air monitor and i was amazed at how dirty those filters would get in just a matter of months. After a while i bought filters that use PC fans because they are much, much quieter. I was lazy and bought them but if you are a little bit handy you can put them together yourself. [https://www.youtube.com/watch?v=wS0LK\_LiqmE](https://www.youtube.com/watch?v=wS0LK_LiqmE) The ones i bought come from here if you have the funds: [https://www.cleanairkits.com/](https://www.cleanairkits.com/)

I'm using the CR boxes, and I'm very happy with them, especially since it cost me less than $200 to make three huge ones, and I assume the filters will last years.

Try a Corsi-Rosenthal box first. See if it makes an impact in your house. Then invest in a proper air purifier that is sized to process the air volume of your house at least 3-4 times a day

You want something genuinely good and cheap? Make a Corsi-Rosenthal Box or two.

I built one yesterday for my garage. Didn't take long at all. Here are some more build designs for anyone who might try to make their own: https://cleanaircrew.org/box-fan-filters/

One is in the front door foyer to blow up the stairs. The other is in the living room. We have a dog that sheds a lot and that's where he spends much of his day.

throw a DYI CR box in there for $50-75 simply to be able to get a big volume of air cleaned quickly and cheaply in an emergency, especially if you are in the path of reoccurring wildfire smoke.