Trying to read up on this online, it seems like there are lots of solutions to print an exhaust shroud/fan setup to pull VOCs from within the printer to the outdoors.
However, it feels like my printer is pulling the air into the chamber.
I’ve found some threads that say the fan pulls air into the chamber and the activated carbon filter, is supposed to eliminate all the VOCs within the print chamber. I.E. There is NO exhaust, instead, Bambu designed this to have the X1C consume all VOCs internally within the chamber.
Is this true???
I’ve also read, that if one pulls exhaust OUT of the printer, it causes internal air chamber flow disturbances that will cool high temp plastics causing poor print quality.
So is the current community thinking (for air quality safety) that you exhaust VOCs, but use a very very low fan setting? I.E. Best of both worlds, pull the fumes, but don’t cause internal cooling drafts?
The fan does weird things when the carbon filter is installed. Removing the filter makes for proper airflow. I’ve done smoke tests to prove that air is removed from the chamber when the chamber fan is on and the filter has been removed.
It’s pretty much horrible at what it’s supposed to do. Air still leaves the printer, but it’s slowed down by the filter and only so some of the VOC’s are captured. It’s pretty much a gimmick since it doesn’t really have enough time to capture enough VOC’s.
This is true. Exhausting out of the printer will pull colder air from outside the printer, causing the chamber to cool down.
There are many ways to solve the VOC’s and particulate issues. My personal method uses a combination of solutions. I removed the carbon filter that’s provided with the printer since it’s useless.
I run a Bento Box inside the chamber that contains activated charcoal pellets and a HEPA filter. Charcoal to capture VOC’s and HEPA filter to capture small particles. The Bento Box works pretty well since it acts as an air scrubber by recirculating the air in the chamber. It’s not a perfect solution, but it helps way more than the filter that comes with the printer and it doesn’t introduce colder ambient air in the chamber.
I also designed a magnetic mount for the printer chamber exhaust so I can easily attach it to a 3" duct that’s going outside. I run an inline 65 cfm duct fan so that I can “pull” air from the printer, since that seems to work better than pushing (at least for my setup). While printing, I only run the duct fan and leave the chamber fan off. Over time this can and will lower the chamber temperature by a few degrees, but it usually isn’t too bad as long as I heat soak the chamber before starting an print. If temperature becomes an issue, I just cycle the duct fan on/off accordingly. When done, I enable the chamber fan in conjunction with the duct fan to clean out the air of the printer and to help cool things off.
Lastly, I run an air purifier in the room that has an activated charcoal filter and a HEPA filter. This step is overkill, but I feel a bit better about this additional layer of protection since the printer lives in my home office and I work in the office a lot, sometimes all day.
I would say there’s no agreed upon solution for printing with hazardous filaments. There are many different ways to mitigate the fumes, but in the end what really matters is what is the amount of exposure you are willing to live with. The location of the printer plays the largest part on the amount of mitigation necessary. If your printer sits in a garage, there’s basically no reason to filter or vent the air since it’s not a place you hang out. I spend a lot of time in my home office and so I take many steps to protect myself. If your printer sits in a large room where the air is turned over quite often, then the saturation of VOC’s and paritcles will be quite low and you may not ever have high levels of exposure.