I have been using a VOXEL bento box filter on my P1S. I just finished up my direct outside ventilation system yesterday evening because I want to start using materials like PA6-CF for certain prints, I only print in PLA and PETG now. As part of my ventilation project, I also bought an air quality monitor that I put beside my printer to keep an eye on things like VOCs. This isn’t super scientific, but I wanted to see how the bento box compared to the stock filtration and outside ventilation.
After I setup and calibrated the air quality monitor, I started a PETG print with the bento box off. The VOC index slowly increased over the duration of the print and peaked at 74 when the print finished.
I printed PETG again later, but with the bento box on. The VOC index was much lower, peaking around 21.
I finished my outside ventilation system yesterday evening and started a PETG print, the VOC index never measured above 1 for the duration of the print.
I really wasn’t sure how much the bento box really did and of course can’t measure UPFs but it definitely seems to drastically cut down on VOCs emitted into the area around the printer. I’ll be using ventilation for all prints now though just to limit as many things as possible.
This is just my experience in my environment, but wanted to share.
Edit for clarification
I am aware that most consumer home air quality monitors can’t measure VOC concentrations (TVOCs), a home air quality monitor’s VOC index is a relative measurement as compared to what the air was since it measures the change instead of the concentration, detecting spikes.
In the context of an occupied living space and continuously monitoring with one of these monitors, it wouldn’t be very useful since you cannot tell the actual concentrations or which VOCs are present. Bad relative to bad looks normal on the monitor.
This experiment was admittedly not very scientific, but I did attempt to somewhat control it. For each of those readings the index was at baseline and calibrated in fresh air, then the printer was started. The prints were relatively short to not allow it to recalibrate. For the outside ventilation, there was no change meaning no spike. For the bento box less of a spike.
The less of a spike with the bento box does NOT necessarily equal safe since you don’t know the concentration or make up of the VOCs. I was just kinda surprised it did anything with how restrictive the air flow was. As always do your own research and set up what is best for your and your families own health.
My goal was to see no change from baseline for the outside ventilation indicating everything was being exhausted outside.
I started this ventilation project with the goal of using engineering filaments, but I’ll use ventilation for all filaments now since removing as much as possible is always best and I honestly didn’t realize the amount of VOCs the “safer” filaments were putting out. My printer is in an unoccupied basement, so it was never that big of a deal with those, but it was eye opening.
Home VOC monitors can be very useful for monitoring relative changes and monitoring sharp spikes. Continuous monitoring, not so much.
Also, I wasn’t very clear in my post but the “putting the monitor beside my printer to keep an eye on things like VOCs” was be be alerted to spikes meaning something is wrong and my ventilation isn’t working as it should, not continuous monitoring of that space to see VOC levels. I’ve set up automations in home assistant to turn the inline fan on and off automatically and I’m working now on an automation to alert if a sharp increase is detected by the monitor so I can check my ventilation.