Brisk Box

Although the classic Corsi Rosenthal box based on a 20-inch box fan is a clever idea, I don't see myself ever using one. It takes up lots of space, it's not very portable, and it's loud. I prefer my [box fan air purifier](https://www.reddit.com/r/crboxes/comments/1hi3z6h/portable_box_fan_air_purifier_with_shroud/) that uses just one 1-inch-thick MERV 10 filter or one 4-inch-thick MERV 13 filter. This design takes up MUCH less space, and I can carry it with just one hand. I do have a Brisk Box Kit from Clean Air Kits. It's a Corsi Rosenthal box with an array of PC fans. While it takes up lots of space and isn't very portable, at least it's QUIET. So I don't have to turn it off because of noise.

Jim Rosenthal (half of the duo behind the Corsi Rosenthal box) did an experiment comparing a Corsi Rosenthal box using MERV 11 filters against a high-end commercial air purifier using a HEPA filter. You might think that the MERV 11 filters (with lower filter efficiency than MERV 13 filters and MUCH lower filter efficiency than HEPA filters) would have been left in the dust (pun intended). In contrast, the cheaper and cruder Corsi Rosenthal box outperformed the commercial air purifier with the HEPA filter. In other words, the cheap and crude air purifier was MORE effective at cleaning the air than the expensive commercial air purifier.

I got a basic brisk box 6 months ago using 3M 1900 filters on it. Placed it in the room with cat litter boxes and it made a huge impact on the amount of dust. Other units I tried have struggled to keep up. Highly recommend clean air kits.

If the room is only 100 SQ ft, one air should be enough. Depending on your budget, Clean Air Kits has quiet air purifiers. Their Brisk Box would work well. They're pretty pricy though. Another option is the Levoit Vital 200s. It's rated for a larger room (390 SQ ft) but you could run it at a lower and quieter speed and get good air cleaning.[Vital 200s Review](https://housefresh.com/levoit-vital-200s-review/) Right now my daily mask is the BNX boat style N95. For a while I was wearing Kleenguard duckbill N95. I can reuse the BNX masks but generally I don't after an 8 hour day. I'm starting to reuse my masks a bit more- wearing them twice before tossing. Most of my work day is in my office solo with the air purifiers running. Today I was in a fairly crowded room wearing my mask for the second time. I tossed the mask once home. Probably would have been better to wear a fresh mask to an event I knew would have a lot of people. I didn't have any extra masks on hand. I had a box of extra masks at work but recently ran out.

Corsi Rosenthal boxes have good CADR. They're DIY box fan air purifiers. Plenty of YouTube tutorials if you ever wanted to try your hand at it.

This right here. I have one of these in my apartment and am planning on getting a second one. Easy to replace fans, easy to replace filters, it's just best option.

Check out cleanairkits.com. Their luggables look sharp and fit the criteria.  But they have slightly louder fans than their Bris box design the bros box isn’t as attractive. No other manufacturer will move the same amount of air at the decibel of these units.  But there is no speed setting, they’re just quiet. Every other purifier will clean less air or be louder and you’ll have to turn down the fan speed.

You need a couple corsi rosenthal boxes. Each one will run you about $90 in today's prices. They perform as well as a $1000 air purifier for 1/11th the price. r/CRBoxes can help. [https://youtu.be/hIuH-2naozI?si=xNUdt\_djOjXdJKja](https://youtu.be/hIuH-2naozI?si=xNUdt_djOjXdJKja)

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...

If you look at cost, CADR/CFM, and noise, nothing on the market beats [Clean Air Kits](https://www.cleanairkits.com/?ref=CCCircle), period. Data to back it up, any entry in gray is a setting that is louder than 50db: [https://docs.google.com/spreadsheets/d/1kQMWNyKfkB0K8A4\_yXMrSAb-CruVl9lASJEpLGLtS8o/edit?usp=sharing](https://docs.google.com/spreadsheets/d/1kQMWNyKfkB0K8A4_yXMrSAb-CruVl9lASJEpLGLtS8o/edit?usp=sharing)

I have several air purifiers and my favourite is a PC fan air purifier from North Box. There are various ones on the market but [North Box is Canadian](https://aidankepo.wixsite.com/northboxsystems). It's available directly from their site or through [Donate A Mask](https://shop.evidencebased.ca/collections/cr-boxes-air-purification). What's nice about PC fan air purifiers is that they're really quiet, quite effective and don't rely on proprietary air filters.

As u/ZedZabeth mentioned, making a Corsi Rosenthal box is a good idea. If you can afford it, a PC fan air purifier uses very little energy, is quiet and takes up less space than a classic CR box. If money is really tight, a respirator mask is probably the easiest, most accessible and cheapest solution. I know the prospect of masking at home is unappealing, but even masking from time to time indoors will lower your exposure.

That is actually completely false. There are several Corsi-Rosenthal Box builds that operate well under 45 dB while maintaining impressive CADR (Clean Air Delivery Rate). Here are a  few examples : * the Honeywell Build (via David Elfstrom): Using a Honeywell HF910 with 3M 1900 filters on speed 1, you get 422 CFM (Dust CADR) at 45 dBA. * The Rob Wissman Build: using 4x 3M 2200 filters and 9x Arctic P14 fans. It hits 556 CFM (Dust CADR) at 44.5 dBA. * The Tempest (Commercial/DIY Hybrid): Running P14 fans at an 8V voltage control setting with 2x AAF Flanders MERV 13 filters, I personally tested this at 184 CFM and only 33 dB (in a 30 dBA background that goes on 34,8 dBA) . Dust CADR 183,9 cfm

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.