HEPA Filter for 3D Printer

thingiverse

**Air Purifier for 3D Printers** The Prusa i3 MK2S is a fantastic printer ideal for hobbyists or light industrial desktop users. While it's a great starting point, it lacks the accessories that would make it truly exceptional. This air scrubber is the first in a series of custom-designed accessories I've created for the i3, which also includes: - Enclosure https://www.thingiverse.com/thing:2396990 - Spool Holder https://www.thingiverse.com/thing:2398480 - OctoPrint Print Server https://www.thingiverse.com/thing:2401423 This accessory is specifically designed to remove VOCs and ultra-fine particles from the enclosure housing your 3D printer. 3D printers produce VOCs and ultra-fine particles as unwanted byproducts of melting and extruding plastics, according to a recent study by Illinois Institute of Technology and The University of Texas at Austin. http://pubs.acs.org/doi/full/10.1021/acs.est.5b04983 Some filaments also emit noxious odors when heated to high temperatures. Initially, I planned to exhaust 100% of the filtered air either inside or outside the enclosure, depending on ambient temperature conditions. However, after several experiments, it was determined that a portion of the filtered air (about 40%) should be recirculated and the remainder ported outside the enclosure. By doing so, the pressure inside the enclosure is lower than ambient, ensuring no unfiltered air escapes during printing. The current nozzle design achieves this balance. The system includes a restrictor plate to adjust the mix to 50/50% if needed, particularly when printing with ABS or other filaments requiring high temperatures. The design features an extended grate that can be used to divide the chamber into two sections: one for silica (drying) and one for activated carbon pellets (VOC filtering). In practice, it was found that the activated carbon pellets provided adequate anhydrous characteristics, making silica unnecessary. If your experience varies, simply insert the expanded grate at a suitable location in the chamber, filling the section closest to the fan with activated carbon pellets and the other with silica. This assembly is based on RJ_Make's design, which incorporates a HEPA filter originally designed for iRobot sweepers and a chamber containing activated carbon pellets. This remix differs from RJ_Make's original: - Screws replace rubber bands to hold parts together, - Part count reduced by combining several parts into one, - Fan exit nozzle has two outputs - One for overboard and one to recirculate filtered air within the enclosure, - Adds exhaust tube from nozzle to enclosure grommet, - Includes enclosure grommet and optional restrictor, - Specifies fan and optional speed controller. 7/12/2017 Update: Removed file "Chamber Top" as it's no longer needed. 1/7/2018 Update: - Restore chamber baffle, - Modify chamber to capture the baffle below filter flange, creating space between Filter and Baffle, - Modify filter to motor and expanded grate by eliminating top several rows of holes to force more air through activated carbon pile, - Support for alternative fans. 3/5/2019 Update: Added strengthened mount courtesy of beikeland.