Re: Enclosure w/ filtration for printing ABS indoors?
I will see how it goes, I will play around with the Arduino just for fun.
This thread contains good information on filters, and I know I pulled it slightly off-topic, so let's get the thread back to that. I just wanted to throw the idea in here because it may help people.
Re: Enclosure w/ filtration for printing ABS indoors?
For testing purposes I ordered this H13 HEPA filter:
https://www.ebay.com/itm/223089845505
I'll do the first test without activated carbon, and I'll see whether this filter does, in fact, remove 99.95% of the air particles in one pass. If it does, then the next step will be configuring a matching, but deep, activated carbon filter to see how much of the TVOC's can be eliminated in one pass.
Here's a guy who uses this same filter to scrub the air, and he claims that he can't smell anything bad even when he prints ABS: https://www.thingiverse.com/thing:2517526 He says he uses just "5-6 10x100x100mm activated carbon filters from EBay." He prints in a tent, so, if true, his solution may (?) be the cheapest-easiest of all for for both containing and eliminating ABS emissions.
He does say his tent can get rather hot inside, so maybe that issue could be handled separately.
Re: Enclosure w/ filtration for printing ABS indoors?
Maybe the simplest thing of all would be to seal the Prusa I3 MK3 inside a giant plastic bag. When it finishes cooling down after printing, you could just take it outside and release all the fumes. I mean, the printer is fairly lightweight and easy to move, so this would leverage that advantage. Moreover, perhaps (?) by keeping it indoors during the print, the large surface area and thinness of the bag would serve to keep the interior from overheating. Admittedly, it would be a very different kind of solution, but maybe it would work.
Re: Enclosure w/ filtration for printing ABS indoors?
This study is interesting because it also measured VOC emissions from various filaments used in 3D printing: https://pubs.acs.org/doi/full/10.1021/acs.est.5b04983
Re: Enclosure w/ filtration for printing ABS indoors?
I have my sensor array working (temperature, humidity,gas index, TVOC, ECO2, and a range of small nanoparticle sizes). I just need to find a suitable temporary enclosure to test it with during a 3D print job.
It seems that the emissions are prone to rising in the air, so putting the sensor near the top of the enclosure would be best.
Re: Enclosure w/ filtration for printing ABS indoors?
This guy has a reasonably good design for mounting his sensors: https://www.thingiverse.com/thing:2320020
I like that it mounts to the ceiling of his enclosure.
Re: Enclosure w/ filtration for printing ABS indoors?
I have preliminary results for printing PETG, which AFAIK no one else has yet reported on.
I put a box over the printer while printing with PETG. Neither the Bosch BME680 nor the SGP30 detected any rise in VOC's. However, the PMS5003 did detect a rise in particles.
So, from this, it would appear that maybe a HEPA filter is sufficient. I suppose it may also be possible that there are VOC emissions that neither sensor (both tin oxide sensors I believe) is sensitive to.
At any rate, since this thread has become a monolog, this is my final post.
[Edit: the above measurements were taken at floor level. When I raised the sensors to the top of the box, then a rise in VOC's was detected.
Therefore, I would say that at least some carbon filtration would be warranted. It may not require a lot though. I suspect some of the designs on thingiverse may be adequate. Somewhere down the road I'll use the same sensors to measure the output after the filtration to confirm whether it was cleaned adequately or not. ]
Re: Enclosure w/ filtration for printing ABS indoors?
So many options on what to try. Looks like you will have to prototype and test.
--------------------
Chuck H
3D Printer Review Blog
Re: Enclosure w/ filtration for printing ABS indoors?
David,
I would love to see your continued results. I have nothing to contribute, but I'm very interested in your findings.
Re: Enclosure w/ filtration for printing ABS indoors?
This vacuum with a ULPA filter claims to be rated at 99.999% efficient at 0.12 microns, so it would probably be the ultimate solution if paired with a carbon filter.
https://www.amazon.com/Atrix-VACOMEGAU-Omega-Vacuum-Abatement/dp/B00DIBZXZU/ref=sr_1_1?ie=UTF8&qid=1535931208&sr=8-1&keywords=ulpa+vacuum
At 73 decibel, though, it would be too loud for me. Maybe if it were paired with a motor controller it could be run at a lower, quieter speed. But how quiet? I doubt quieter than my Miele vacuum, which is also a bit too loud for me.
So, for those reasons I'll first be building the exhaust fan from thingiverse
https://www.thingiverse.com/thing:2105113
and using PWM to control the 120mm Scythe fan that it will be running.
https://www.ebay.com/itm/Scythe-Grand-Flex-120-mm-Case-Fan-2400-RPM-4-pin-PWM-SM1225GF12SH-P/171640813062?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
Reportedly it will be fairly quiet if run at a low speed. To that end, I'll be using this to control its speed:
https://www.aliexpress.com/item/Signal-Generator-PWM-Pulse-Frequency-Duty-Cycle-Adjustable-Module-LCD-Display-1Hz-150Khz-3-3V-30V/32835541668.html?spm=a2g0s.9042311.0.0.5d154c4dXI2B2V
which I also used in this other project:
https://shop.prusa3d.com/forum/user-mods-octoprint-enclosures-nozzles--f65/quieting-the-r3-blower-design-t23304-s60.html
Re: Enclosure w/ filtration for printing ABS indoors?
Unfortunately, the thingiverse design I was planning to use seems to be a fail. I tried running it with the recommended Scythe PWM fan and an H13 electrolux filter, and I get no detectable airflow through the filter. I'm driving it at 12v at 100% duty cycle. I even tried sealing around the fan with blue tape, because some airflow had been bouncing back that way. However, even with that, the same result. Air gets sucked in and then somehow blown back past the fan blades anyway. If this is to work, it appears that I will have to use a lesser HEPA filter. 😥
Re: Enclosure w/ filtration for printing ABS indoors?
From what i saw thingyverse guy used two fans?
Compare that fan with noctua industrial
Re: Enclosure w/ filtration for printing ABS indoors?
I think it's going to require something far more powerful to get any meaningful amount of air through that H13 filter. When I put my hand up next to it, I literally don't feel anything coming through it at all.
I haven't seen a single post that shares this problem. I can only assume that others are using HEPA filters that are rated much lower.
Re: Enclosure w/ filtration for printing ABS indoors?
I think it's going to require something far more powerful to get any meaningful amount of air through that H13 filter. When I put my hand up next to it, I literally don't feel anything coming through it at all.
I haven't seen a single post that shares this problem. I can only assume that others are using HEPA filters that are rated much lower.
You can't fell the air with your hand means nothing.
Just use a thin small paper, if it get suck without drop then is OK.
I dont belive that HEPA is special and much different from the others, HEPA is HEPA, on my filter im using 40mm of hepa with prefilters + 50mm of carbon and still can pass air
Noctua Industrial fans are better, the 3000 version
Re: Enclosure w/ filtration for printing ABS indoors?
I think something like this could probably develop the required suction and yet (hopefully) still be quiet:
https://www.amazon.com/gp/product/B07FPFVZTZ/ref=ox_sc_saved_title_1?smid=A2AW0W4FKP16S5&psc=1
It says 351CFM with 32dBa, which, if true at the same time, would be pretty remarkable. It comes with a speed controller, so I could dial it back, but it would be nice to have the extra headroom in case it's needed to pull air through the H13 HEPA.
If not that, then this at half the price might do it:
https://www.amazon.com/gp/product/B077492C4C/ref=ox_sc_saved_title_2?smid=A2PQGFJXAT8J9K&psc=1
And if not that, then surely this would do it:
https://www.amazon.com/iPower-Inline-Ventilation-Exhaust-Grounded/dp/B07D8RB954/ref=sr_1_14?ie=UTF8&qid=1536362957&sr=8-14&keywords=in-line%2Bfan%2B12%2Binch&th=1
Re: Enclosure w/ filtration for printing ABS indoors?
David, what do you want to grow in your enclosure to use those huge grow tent blowers? 😆
On a serious note, I think radial fans like shown in link 2 and 3 will be better for this application.
An axial fan will produce large air flow with very little pressure difference, a radial fan has lower flow with bigger pressure difference, and we need that pressure to suck the air through the filter.
I bought this fan:
https://www.neuhold-elektronik.at/catshop/product_info.php?products_id=6595
but don't know when I will find time to work on my filter solution...
The fan produces 30mm H2O pressure.
An axial fan with slightly higher power rating has 1/10th of that pressure rating.
Re: Enclosure w/ filtration for printing ABS indoors?
I agree, that huge fans are not for this application, and take lot of space. The bigger the fan less pressure they produce.
I would go with Noctua Industrial series and two of them if required. Again my filter is much more thicker and dense then yours and still one fan is ok to handle it
Re: Enclosure w/ filtration for printing ABS indoors?
David, what do you want to grow in your enclosure to use those huge grow tent blowers? 😆
On a serious note, I think radial fans like shown in link 2 and 3 will be better for this application.
An axial fan will produce large air flow with very little pressure difference, a radial fan has lower flow with bigger pressure difference, and we need that pressure to suck the air through the filter.
I bought this fan:
https://www.neuhold-elektronik.at/catshop/product_info.php?products_id=6595
but don't know when I will find time to work on my filter solution...
The fan produces 30mm H2O pressure.
An axial fan with slightly higher power rating has 1/10th of that pressure rating.
Well, the price is certainly appealing on the fan that you bought, but it looks awfully small to do the job don't you think? That said, I'd be very interested if you manage to make it work.
Re: Enclosure w/ filtration for printing ABS indoors?
Well, the price is certainly appealing on the fan that you bought, but it looks awfully small to do the job don't you think? That said, I'd be very interested if you manage to make it work.
Size don't mean nothing here, thats a aggressive fan and as i said the smaller the fan more static they have.
eg: https://www.aliexpress.com/item/Free-shipping-High-pressure-Mini-24V-DC-3-phase-Brushless-DC-Centrifugal-Blower-Hot-and-Cold/32627597541.html
6 kPa thats 611,829 mm H2O
Re: Enclosure w/ filtration for printing ABS indoors?
However, it's likely to be unacceptably loud. Somehow there needs to be the right balance between loudness and air pressure. I'm really not sure what the answer is.