DIY Air filter | HEPA + Activated Carbon

Purpose

A 3D-printed fan unit that attaches to the FY0293/30 HEPA filter by friction fit and pulls air through the filter. In the model, the air outlet side can be recognized by the built-in fan grill on PART 1. 

Required parts

• HEPA filter: FY0293/30
• 120MM PC Fan: standard PC fan (prefer high static pressure), I used the Arctic P12Pro/Max
• PWM Fan controller (with speed adjustment)
• DC connector (female, panel mount)
• DC power supply: 12 V, ≥ 2 A
• Wiring
  • Maximum current: ≤ 5 A
  • Recommended: AWG 18 (≈ 0.82 mm²) or AWG 16 (≈ 1.3 mm²) for extra margin
• 8x Fan screws (standard)
• Optional: screw terminal or heat shrink tubing (for cables)

Polarity: make sure to solder + and − correctly.

Print information

• Material: PLA
• Layer height: 0.2 mm
• Infill: 20–30% (Cubic)
• Perimeters: 3
• Tolerances: designed for friction fit. Adjust “horizontal expansion” in your slicer if fit is too tight/loose.
• Support: Yes, suggested to use support in the screw holes of PART 1 and in the holes of the DC connector and the fan controller. (Tree, Organic)

Assembly

1. Fan (PART 1)
   • Mount the fan in PART 1 with airflow directed towards the side with the built-in grill.
2. Controller & DC connector
   • Mount the fan controller in its hole, align the little tab with the square in PART 1.
   • Mount the female DC connector in its hole.
3. Wiring
   • Solder the DC connector wires to the fan controller input (observe polarity).
   • Alternatively you can use a screw terminal between the DC connector cables and the fan controller cables. This way you can easily disconnect/reconnect.
   • Connect the fan controller output to the fan.
4. Close (PART 2)
   • Mount PART 2 on the other side of the fan with standard fan screws.
5. Testing
   • Connect the 12 V power supply.
   • Verify that the fan runs and speed can be adjusted.
6. Attach to filter
   • Push the complete fan unit into the FY0293/30 filter.
   • Friction fit ensures a tight connection.
   • Optionally mount PART 3 on the bottom side of the filter as an end cap (these filters are often open on both ends).

Does it work?

In short YES, It works pretty well. I built this filter because I bought a “big brand” smart air filter for way to much money. When I saw the simple design of the air filter I thought to myself why not make it myself. Depending on the fan you choose you can get around the same throughput as a basic air filter from a big brand name like Philips. The filter is the same as in the original “big brand” filter units. So you will get about the same in results depending on the volume that you filter and the fan you use. 

I hope you like the design and it works as well for you as it does for me.