HEPA and Charcoal Filter for 120mm Fan in Original Prusa Enclosure

This is a simple enclosure air filter for the Original Prusa Enclosure. 

Materials:

Common:

• 120mm Fan (I used Noctua)
• HEPA filter
• Charcoal filter cut to size

Option 1:

• 4x M3x30
• 4x M3n
• Cut HEPA filter to size

Option 2:

• 4x M3x16
• 4x standoff M3x thickness of HEPA
• 4x M3x30

Instructions:

NOTE: The image shows the HEPA filter inserted BACKWARDS. Insert it so that the airflow is pointing towards the outside of the enclosure.

Option 1:

1. Orient the part so that the circular hole is on the bed
2. Scale the part in Z to fit the HEPA and charcoal filter (thickness)
3. Print the part
4. Insert the HEPA and charcoal filters into the part
5. Cut out the hexagon cutout on the back left of the enclosure
6. Use 4x M3x30 and 4x M3n to bolt the filter to the fan (longer screws may be necessary)

Option 2:

1. Orient the part so that the circular hole is on the bed
2. Print the part
3. Insert the charcoal filter into the part
4. Use 4x M3x16 through the part to 4x standoff M3
5. Push the standoffs through the HEPA filter
6. Cut out the hexagon cutout on the back left of the enclosure
7. Use 4x M3x30 to bolt the standoffs to the fan (longer screws may be necessary)

Controlling the fan:

You have a few options to control the fan:

• Connect it straight to power (the simplest)
• Use a relay to switch it on and off (what I used)
• Use a speed controller to adjust the speed