This project is comprised of three primary components: a 3D-printed housing, a fan, and an activated carbon filter. Links to everything you'll need is in the parts list above.
Choosing a fan
You have two options for your 80mm fan -- you can either solder your own fan circuit and add your own switch, or use one that's plug-and-play.
To save time, I'm using a 5V fan with a switch and wire built in. You can probably save a few bucks by soldering your own fan circuit, but the one I'm using is quite powerful and is only about $11. The downside is this fan has a lower CFM, meaning you'll need to keep it closer to what you're soldering.
If you prefer a higher CFM fan, you can find one on Amazon, though you may need to bump up to a 12V fan to get a really high CFM.
If you'd like to solder your own fan circuit instead of using a USB fan, see the instructions on Instructables.
For the housing, we're going to use an excellent design created by rdmmkr on Thingiverse. Download the model from Thingiverse and print the five main parts of the model:
- The main housing left half
- The main housing right half
- The removable filter cartridge front half
- The removable filter cartridge back half
- The front panel plate
Don't have a 3D printer?
If you don't have a 3D printer, not to worry! I wrote a short guide on how to get your 3D model printed without owning a printer.
Remove the rubber feet and grilles that came with the fan.
Then, close the two halves of the main housing around the fan, ensuring that the fan is oriented correctly—to suck in air from the front and push the air out the back.
Finally, use the four included fan screws to secure the fan and its grill to the housing. This will also hold the back part of the housing shut.
There's an internal hole in the unit that's meant to run the fan cord through if you created your own fan circuit. If you instead used a USB fan (as I did), you'll want to plug this hole so you don't get any air leakage.
To do this, simply use a bit of electrical tape or hot glue. Fan suction will hold the tape in place tightly.
The front panel holds together the front part of the housing and provides a spot for a small rocker switch (in case you decided to build your own fan circuit). Use two small screws to secure it in place. If you don't have any small screws laying around, you can also use super glue or epoxy to hold everything together.
The activated carbon filters I ordered are 130x130x10mm. Using a pair of scissors or a box cutter, cut each one down the middle twice, resulting in four 65mm² squares of equal size. This is exactly the size you'll need.
The ones I ordered came with five filters, meaning you get a total of 20 filters after cutting. Not bad.
Every electronics DIY-er needs a good soldering iron. The Howchoo team uses soldering irons all the time for projects like Gamepad Zero or our hacked Raspberry Pi keyboard.