Transcript
Today we are covering when it is appropriate to ventilate 3-D printers, and I will present a few solutions for how it can be done. I also reference some of 4D Filtration’s Data and Simulations throughout this video, so the link to those will be below.
So, what even is ventilation? This is a term often thrown around when using paints, epoxies, and adhesives. Natural ventilation can just involve doing said activity outdoors, ideally where there is a slight breeze. But we can’t 3-D print outdoors without protection from the elements.
The best location for most people will be to have resin printers in a garage or workshop while cracking a window or door. This will continuously air out the space. During winter, we typically need to keep both filament and resin in a heated chamber to prevent defects like warping, so we will add an external heat source and just vent after the print finishes if it is in a garage or workshop.
Venting while indoors is a bit trickier, and this is where active ventilation shines. Active ventilation is the use of a fan to force air out of a space through a hole in the wall. This hole can be a window or a drilled hole, like for a dryer.
The best type of fan for this purpose will have a high static pressure, which will be a centrifugal or mixed-flow fan. Some axial types, such as a 120 by 38 millimeter fan, could work if they are rated at least 20 Watts. Anything less could be overwhelmed by wind.
The fan creates an area of negative pressure that pulls external air into the space. When used in a garage or workshop, this brings in cleaner outdoor air. When used indoors, this prevents contaminated air from spreading into the rest of the house. We can demonstrate this by using dry ice and water vapor to visualize air flow patterns.
To control the flow of air we will attach flexible 4-inch vinyl duct to both sides of the fan. The intake to the fan should be passed through one of the ports on the side of the grow tent, and the other end of the duct will be attached to a window adapter of your choosing. It can be rigid plastic like those from a portable AC unit, fabric, plywood, Styrofoam insulation, acrylic, polycarbonate, or cardboard, in a pinch.
Make sure you have a good seal around the window and the adapter. If you don’t have a window in your desired space then consider using a hole saw bit for a drill to make your exhaust port.
Enclosures are often used to contain any contaminated air so it can be directly vented outdoors. A vented enclosure prevents the 3-D printer’s emissions from mixing with cleaner air in the room. They also help insulate the printer and keep sunlight away from resin.
Grow tents are popular for resin printers since they are affordable and easy to set up. Enclosures are primarily used indoors, but in a garage or workshop they can protect the print from debris and provide insulation.
Now some of this may seem excessive when you only want to use PLA, and I totally agree. PLA produces low levels of VOCs compared to other filaments, but it still produces a high number of Ultrafine Particles (UFPs).
UFPs are airborne particles under 100 nanometers that can cross the air-blood barrier in our lungs, where they can cause cell damage throughout the body until they are filtered by the kidneys or intestines.
Engineering filament like ABS, ASA, Nylon, or Polycarbonate will produce higher levels of UFPs, as well as some VOCs like Styrene that we want to capture or vent. The emission rate of UFPs from a resin printer is similar to that of PLA but resin off-gasses a variety of nasty VOCs, most of which are odorless.
So we can probably agree that 3-D printer setups using resin or engineering filament should be vented. If you are only printing with PLA, then any small air cleaner or DIY box fan with a MERV 13 filter to capture UFPs is sufficient. When in a garage or workshop, 3-D printers don’t have to but can be vented continuously if the area is high-traffic. Otherwise, you can vent after the print finishes to keep the enclosure toasty during winter.
If ventilation is not an option for your FDM printer indoors then you can use filtration, but for resin printers, filtration is only recommended for mitigation. UFPs are readily captured by MERV and Hepa filter material, but the effectiveness of capturing VOCs with activated carbon varies wildly, with the specific chemicals off-gassing being just one variable.
To round everything out, resin printers ideally should be outside the home. If resin printers are indoors then they must be vented using an enclosure, duct, a fan, and a window adapter. Basic filaments on an FDM printer do not need to be vented, but the UFPs should be captured. Engineering filaments like ABS should be used outside the home or vented but they can use filtration if ventilation is not feasible.
Ahhh fresh air
if you have any questions at all, just comment below and I’ll give a brief answer.
