Many people find the smell of plastic from a 3D printer to be particularly noxious. Plus, some studies have shown that plastic fumes are toxic, especially to small children or people who have asthma. But filtering 3D printers is tricky: evacuate too much air and there won't be enough heat for a quality print; evacuate too little air and there won't be much odor reduction.
If you have access to a window, the safest thing to do is to vent the fumes to the outside using this vent adapter. But if that isn't feasible, then reduce the complaints about smells with this active carbon filter kit. Its tuned to reduce the odors associated with 3D printing while retaining enough heat for a good print. The activated charcoal filter has an especially high carbon content (300g/sq ft) and is proven to remove odors and volatile organic compounds from air down to 3 microns in size. We have no idea if that decreases the health risks since there aren't any scientific studies on the subject, but reducing complaints about the smell sure makes it easier to run a 3D printer in the house.
The carbon air filter is designed to work with any 3D printer enclosure by drilling the right sized holes to mount the filter. Of course, all 3DUPfitters enclosures come with the mount point pre-drilled and ready to go.
Note the price. Industrial level filtration systems go for north of $800. If you want the best, then this isn't for you. The picky people who've complained about smells around here say its no longer an issue. The smell went from permeating the entire upstairs to being noticeable only when close to the printer. It doesn't completely remove all of the smells.
Everyone has a different sensitivity to odor, so give it a try for 10 days, and if it doesn't meet your expectations just return it for a refund. (You pay return shipping.)
Every enclosure comes pre-drilled with the vent and mounting holes, but this kit adds:
5V USB with 12" cable
3D Printed Charcoal filter holder
Charcoal filter with 375g/sq.ft carbon content that removes particles down to 3 microns.
The fan can either be plugged into a USB power supply (not included) or the wires stripped and connected directly into some models of 3D printer. Note that USB wire is only around 12" or so, and won't reach to a wall socket. We plug ours into a Raspberry Pi running Octoprint, but you'll have to purchase some other form of USB power supply if you don't have one already.
One downside to carbon air filters is the carbon eventually wears out with use. This filter is priced so cheaply you can afford to just replace the whole thing, and get the latest design in the process.