There are two main types of filters used in 3D printers:
- HEPA filter – this removes VOPs and odour in the air
- Carbon filter – this removes VOCs and odour in the air
HEPA is a standard for removing particles of .3um or greater. It does not remove gases. HEPA filters are ideal for vacuum cleaners, for example, as they remove smoke, soot and pollen, but they don’t actually prevent the major concern emissions of 3D printing. Thus, a HEPA filter will remove small particles but not VOC fumes.
Activated carbon charcoal filters remove VOCs emitted by 3D printing. Carbon filters are designed to trap much finer molecules, which are just a few hundred picometers in size through adsorption (not absorption). The gases that a carbon filer can trap would pass right through a HEPA filter without any effect.
In terms of 3D printing, it is unclear if a HEPA or carbon filter is more appropriate as both have their uses. What is clear, however, is that either type of air filter is a lot better than no filter and that a combination HEPA/carbon filter is the best.
In terms of enclosed vs ‘open’ printers, many schools or school districts require 3D printers to be fully enclosed (i.e. no exposed moving parts). From an air filtration point of view, enclosed printers are probably better as open printers would require impractically large air filters to be effective.
In all cases, we recommend using 3D printers in a room with great ventilation (e.g. open doors and windows, put air conditioning/ air filter on etc).
More Reading
Makers Empire Recommendation: printers in a school, business or home environment should be enclosed and have a HEPA or carbon filter. Ideally, a printer should have both a HEPA filter and a carbon filter and be used in a well-ventilated area.