You Can Just Print an Air Purifier | Hacker News Reader

You Can Just Print an Air Purifier

aftermath.site

40 pointszdw9 comments

If you go the old school "filter taped to box fan" route, be sure to add a shroud for the corners, as blade tip turbulence there actually causes reverse air flow. See the article by the 'R' of Corsi-Rosenthal.

https://www.texairfilters.com/how-to-improve-the-efficiency-...

I bet this moves more air per unit noise and/or power too.

it would be interesting to measure the airflow with a decent anenometer that works at low airspeeds (I've had success with https://www.amazon.com/BTMETER-Handheld-Anemometer-Velocity-...).

My intuition is that the 5 case fans at 72 CFM each are deeply underpowered for the job of moving air through a filter medium, especially in an array pointed into a mutually turbulent unsealed box, and that you would do way better with something like an AC Infinity Cloudline S8, which moves around 800 CFM, aimed directly at the filter in a sealed environment.

It's pretty common for case fans (and even industrial fans) to be used for cheap airbrush stations, which have much smaller filter face openings. These generally don't pull even 1 linear feet/min at the station face, even though they're theoretically rated for over 150 lfpm without the filter media in place.

There are actually two different types of case fans - high airflow vs. high static pressure.

The CFM number alone doesn't show that.

I assume the high static pressure ones would do a much better job in this context.

A bit ironic to me to print the case with plastic which'll just end up degrading into microplastics over time, creating a more toxic environment. Like a toothbrush made of sugar or a mop made of charcoal.

Wait till you find out what the filter is made out of

Are every commercial filters made of plastic?

Kind of an edge case because the printing process itself is where the far greater known health risks lie. Honestly, I don't like the design because it's probably loud and expensive (for proper high static pressure fans) and doesn't have as much filter area as box fan-based DIY filters.

It's cute, but I'd prefer a double box fan and 4 or 5 filters 3D printed frame.

Incredible. Need to try this over the weekend.

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