Simple HEPA + Carbon Filter

I wanted a combo HEPA & active carbon filter, but with a short print time, and minimal BOM.  Other builds tended to be very complicated builds, or long prints.  Should take about 1-2hrs per filter.  No supports.  Removes VOCs and Particulates. 
 

This should cost you about $2-3 USD, and some bits laying around.  The only part witch is very particular are the filters.  You need to get exactly the ones below.  Everything else, can be adapted. 

I find two is good enough to keep the air clean in real time for me. 

Print both halves, fill the vented half with activated carbon. ABS/ASA/PETG, no supports. 

You can use any 50mm fan you like, but you will need a screw that can connect to the nut on the other side (width + 5mm) 

I use the clay to make a gasket between the edge of the fan and the plastic. You could get away with a lot here, but I use Plastelina because it never dries out. 

Hold  both sides together with some rubber bands, or some string.  It doesn't require much force to hold it together.  The filters come with their own soft gasket, so they seal well enough on their own. 

BOM 

• Filters XL-618A ($2 each, washable)
  • https://www.aliexpress.com/item/1005005988398889.html
• Fans, 5015
  • what ever you have laying around (50mm)
  • https://www.aliexpress.com/item/1005006228459976.html
• M3 nuts x2
• M3x20mm
• Some smallish rubber bands. 
• plastelina/clay
  • or something similar for a gasket 
  • https://www.amazon.com/plastelina/s?k=plastelina
• Activated Carbon (NOT ACID WASHED, $4/kilo) 
  • https://www.aliexpress.com/item/1005004477553967.html
     

PSA:  Not all Activated Carbon is the same.  Acid wash carbon can cause the metal in your machine to rust.  No matter where you source your AC from, test it in a box with random metal bits first.  

OnShape:
https://cad.onshape.com/documents/eb54b9a1c9c37bd6d57b681d/w/798c52e166088592a2c49275/e/e20f77ec4a80bab1b57ec685?renderMode=0&uiState=664b73e7ab84df5809fde2f0