Desktop Air Purifier

This simple 3D print converts a standard 140mm PC fan into a stylish desk air purifier.

Bill of Material

• 1 x 140mm PC fan, 27mm height (e.g. "Arctic P14 Silent" - pressure optimized)
• 4 x M4 x 40 screws
• 4 x M4 threaded inserts
• 1 x 12V 2-pin DC power jack
• 1 x 12V power supply
• 4 x 6mm diameter rubber feet (optional)

Printing instructions

No supports required.

The fan part and the container part are printed upside down.

The lid and the spacer need a special preparation during slicing. Both parts are used to keep the activated carbon pellets contained while air flows through. The downloaded parts are designed fully solid and require you to add a modifier before slicing to remove top and bottom layers at the specific regions. 

In PrusaSlicer, add a cylinder with a diameter of 128mm right into the center. Set “Bottom solid layers”, “Perimeters” and “Top solid layers” to 0. Set “Fill pattern” to “Gyroid” and “Fill density” to 25%. This will produce a sturdy pattern, which allows good airflow and keeps the pellets contained.

I recommend printing the spacer in a contrasting color. My intension was to print either a black cube with a red spacer or a white cube with a golden spacer, which was my favorite combination. Since I didn't have enough white left and my red filament seemed to be “cherry red” (which does really go well with black) I printed this black and gold combination that unintentionally looks a bit like a famous Middle Eastern building…

Assembly Instructions

Insert the threaded inserts into the holes on the printed fan part. Be careful not to melt the walls. Insert the fan into the printed fan part so that the air is blown out through the ribs. Cut the connector from the fan's cable and pass it through the holes in the spacer and the container part. Stack the three parts together and fix the parts with the screws.

Solder the cable to the DC power jack and attach it to the mounting holw at the back of the conatiner part. Just as a reminder to avoid additional work: pass the cable through the nut and then through the hole first and then solder the cables to the power jack.

Now you can fill the container with activated carbon pellets from below. Depending on the pellet size, you should adjust the filling level (⅓ for smaller pellets, large pellets can fill up the whole container).

Screw in the lid and you are good to breathe in purified air…