4" / 120mm inline HEPA 86880 / 40320 + Carbon Pad Filter

thingiverse

This one is a remix from shark29's project that I made to work as an inline filter. I'm currently using this as an exhaust filter in my abs printer enclosure tent as the inline 4" ducting allows it to be mounted around easier. This project uses HEPA 86880 / 40320 vacuum hepa filter and has room for a carbon filter pad pre-filter. I recommend pairing it with a 4" duct booster fan or mixed vent fan. Just place the filter inside the box with the carbon filter pad inline before the hepa filter so that it can catch more of the dust / larger particulates and prolong the life of the hepa filters. Then press the unit together and seal with duct tape / whatever you want and it's good to go. Changes: ======= The system is made to be duct taped / sealed from the outside instead of with the provided screws. I didn't remove the screw holes because I was being lazy but they shouldn't effect the operation at all. I added an extra press-fit bit on the inside that should be roughly the same dimensions as the cardboard frame on the HEPA filter so it shouldn't cut down the CFM by too much and should help to prevent some air from moving around the filter box. I removed some of the material that worked as a stand since it was no longer necessary for the inline operation and would get in the way if you wanted to seal it by wrapping duct tape around the box.