r/crboxes

Duct tape seems to be the norm for Corsi Rosenthal boxes and other DIY air purifiers. The first drawback of duct tape is the sticky residue that it leaves behind. The second drawback is the VOCs produced. While the classic Corsi Rosenthal box is for removing particles and not VOCs from the air, it just seems wrong for an air purifier to be actively producing VOCs.

Painter's tape and gaffer tape, on the other hand, do NOT leave a sticky residue behind and do NOT produce VOCs.

Pretty much what's in the title, though I'm also interested in knowing what are the complete possibilities and if they depend on the filters used then of what types and characteristics of filters exist.

Hey guys! I was thinking recently of changing the fans that came with my pc. Im mostly looking at Arctic as an option since it s the most affordable and efficient brand available in my country.

I ve heard that the P12/P14 PROs have a weird rattling noise when reaching higher speeds and that concerned me cause Im looking for someting as silent as possible.

Ps: Im kinda new to this so im not that knowlegeable abt RPM/PWM/PST...

First time I've ever dabbled in air purifiers in general, but I heard of the AirFanta 3Pro and it seems the best around!

Energy efficiency, CADR, filter cost, noise - you name it!
Seems it even beats the high-end $1,000 large purifiers (in theory) if you use 2.

That said, there's a few features I wish it had.
If possible, I was wondering if you guys might know how to add any of the following (ideally no soldering necessary).

1. A sensor to detect air quality level, and auto turn the fan on when needed
2. Something that can auto toggle the fan speed based on the air quality level severity (saves electric bill and noise)
3. Automation for dying down during certain hours and/or conditions like movement.
4. Washable prefilters
5. Filter health status indicator (not just time-based)
6. Separate carbon filter

The first 3 are the big ones.
I've heard someone say Home Assistant could help.
Is that best, or better idea?

4-6 are minor, but still nice.

Regarding the first 3.
It would be best if it's able to accomplish this in a relatively discreet/neat way.

I might be willing and even want to have the particle sensor far away so some purifiers are extra aggressive in some places. But otherwise, I'm open and may even prefer a method to make it relatively compact/hidden.

Most Corsi Rosenthal boxes consist of filters taped to cardboard or foam board. The problem is that the filters become dirtier as they capture more and more particles. Eventually, it will be necessary to replace the filters.

Unfortunately, removing tape from cardboard or foam board will tear it up and damage it. What's the standard solution? The instructions I've seen for building Corsi Rosenthal boxes never address this matter.

Here is my solution: Before taping filters to cardboard or foam core board, I put clear packing tape on it to protect it. I know it looks tacky, but at least I can keep using the cardboard or foam core board over and over again rather than expend the effort to obtain new cardboard/foam board and go through the entire build process all over again. Even if I were a billionaire, and money were no object, I would still insist on the protective layer of tape. Why does it feel like I'm the only one who has acknowledged the issue and done something about it?

Mine could not be any simpler:

4 pcs - Teucer 12038 fans - these are 38mm fans that run at 3500 rpm. About the same noise as the P12 Pro, but the CFM and static pressure is much higher. There are many brands to choose from - Wathai, SXDool, GSDTime, etc. They have similar specs, fan blade design and construction.
4pcs - 10x20x1 air filters - very common and relatively cheap.
60 watt speed controller - I undervolted to 8v and still get very good air flow.

Miscellaneous items:
Top and bottom corplast
A few bolt and nuts
Fan backets
Painters tape

Overall cost is relatively cheap given the CFM, static pressure, ambient noise. I built 4 of these and spread them out across the house. If I want to quickly clean the air, I change the voltage from 8V to 12.3V. I can fine tune airflow across the house based on the voltage set on each unit.

The unit takes less than one square foot of space so I can easily move it around. When it's time to change filters, I just assemble a new 4-sided unit and then simply move the top and bottom parts to the new filters. It's less than 30 minutes to complete.

I wear a respirator and know this wouldn’t be a true fume extractor for welding but would it help keep the air a bit cleaner in general/maybe help with grinding dust (minimal) or is that not what these are for? Do I just need the right filters? Box fan with 5 filters would be what I built if it would work for my use and then potential suspend it from the ceiling if that’s okay placement?

Thank you