CleanAirKits - Brisk Box (CleanAirKits)

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)

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

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.

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

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!

I've got a corsi Rosenthal box, a levoit, a Honeywell, and one other than I can't remember the brand of right now. The CR box has a high CADR but is noisy. Works great for clearing the air or when I have guests over. The levoit is quietest and I use that in my bedroom. Makes nice background noise. The Honeywell is fine. Picked it up 2nd hand from a thrift store for $10. I use to just help keep dust and pet dander out of the air.

This is what I use. I have a couple set up, one on the main floor and one near my pet (guinea pig) cages. Does a great job. Yeah it's ugly, but the only cost is the fan and the filters themselves, and it really works.

Good call on the corsi-rosenthal box. I have a Honeywell. Though it can run insanely quiet compared to my CR box. I ended up hacking the PCB of the Honeywell to add automation via an ESP32. The CR box runs in the basement so it's just on a smart outlet. Also nice building it with aluminum. I did mine out of furring strips and cabinet screws. Lol.

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.