Re: Enclosure w/ filtration for printing ABS indoors?
As far as dust sensors go, I'm going to assume that the laser particle sensors are more accurate than the IR diode type. Adafruit's laser particle sensor is the PMS5003. There's a newer sensor available, which is the PMS7003. I'm not sure which one is better. The PMS7003 is more compact. A study comparing the two shows that their particle counts are highly correlated: http://aqicn.org/sensor/pms5003-7003/ Also, they are priced the same, at $15.88:
https://www.aliexpress.com/item/PLANTOWER-Laser-PM2-5-DUST-SENSOR-PMS7003-G7-High-precision-laser-dust-concentration-sensor-digital-dust/32819185686.html?spm=2114.search0604.3.30.729d3794RQ2Bz2&ws_ab_test=searchweb0_0,searchweb201602_2_10152_10151_10065_10344_10068_10130_10342_10547_10343_10546_10340_10548_10341_315_10545_10696_10084_531_10083_10618_10307_5013513_5013713_10059_5013613_100031_10103_10624_10623_10622_5013813_10621_10620,searchweb201603_45,ppcSwitch_7&algo_expid=478eaed0-7d85-4f75-8bdf-39a68f4c107f-4&algo_pvid=478eaed0-7d85-4f75-8bdf-39a68f4c107f&priceBeautifyAB=0
and
https://www.aliexpress.com/store/product/PM2-5-Air-particle-dust-sensor-laser-inside-digital-output-module-air-purifier-G5-PMS5003-High/1678083_32821824448.html?spm=2114.12010615.8148356.1.70057761EciyXq
At present, I'm not sure if their data communication is the same or different. Anyone know? Maybe a comparison of their user manuals would reveal an answer. The Adafruit library works with the PMS5003 ( https://www.adafruit.com/product/3686 ), so that might be one reason for selecting the older model if there are any interface differences.
The SDS011 is another laser detector, and it has UART output, so it might be slightly easier to read the data: https://www.aliexpress.com/item/Nova-PM-sensor-SDS011-High-precision-laser-pm2-5-air-quality-detection-sensor-module-Super-dust/32371221952.html?spm=2114.search0604.3.15.7c8b39d629DGFV&ws_ab_test=searchweb0_0,searchweb201602_2_10152_10151_10065_10344_10068_10130_10342_10547_10343_10546_10340_10548_10341_315_10545_10696_531_10084_10083_10618_10307_5013515_5013615_10059_5013715_100031_10103_10624_10623_10622_10621_10620_5013815,searchweb201603_45,ppcSwitch_7&algo_expid=dd960e2e-0b3a-4a59-b95d-b8f297256760-2&algo_pvid=dd960e2e-0b3a-4a59-b95d-b8f297256760&priceBeautifyAB=0 There are numerous github libraries for reading it: https://github.com/search?q=sds011 Also, it's air sample can be provided by a tube, so it could be located out in the ambient air, instead of inside the enclosure where the temperature may not (?) be as favorable to accurate measurements.
In addition to the particle detector, I will need a VOC detector. I haven't surveyed those yet, so presently I'm not sure which ones are the best. Both Adafruit and sparkfun have air quality sensor's on breakout boards, and maybe (?) other vendors with libraries do as well. If you have an opinion about which VOC sensor is the best, please post! Since we don't know much about the filament emissions during printing, it seems like almost a lucky shot in the dark to find a suitable VOC sensor. It may turn out that none of them are sensitive to the emissions of interest.
I doubt whether any of the above will be accurate, because I'm guessing they won't be calibrated. However, they can provide relative measurements, which is good enough for me.
Re: Enclosure w/ filtration for printing ABS indoors?
Even though it's crude, this youtube video demonstrates how easy it can be to make your own DIY deep bed activated carbon air filter:
Re: Enclosure w/ filtration for printing ABS indoors?
I just now found a previous thread which also addresses the topic of this thread: https://shop.prusa3d.com/forum/improvements-archive--f85/filtering-abs-fumes-options-for-enclosure--t1725.html
It contains a link to a $350 commercial 3D Printer enclosure that includes a recirculating HEPA plus activated carbon filtration system: https://www.fabbaloo.com/blog/2015/3/1/finally-a-3d-printer-filter-accessory which is on-point with what I've been thinking about.
Alternatively, I've also been thinking that since my Miele vacuum cleaner already includes good HEPA filtration, it could be used to evacuate the air from an enclosure at the end of a print by first pulling the air through a, say, 18 inch deep bed carbon filter. Such a deep bed might require the greater force of a vacuum cleaner to move the air through it in a timely manner. So, that would be a one-pass solution, and it may be the fastest solution. If nothing else, it might be a workable short-term solution that could be put together fairly quickly and inexpensively as a proof of concept and to get a better handle on what parameters are necessary to get excellent results. Also, since the Miele already is variable speed, I could adjust the flow rate, if needed, to get better absorption through such a deep bed activated carbon filter since, at present, the minimum required dwell time is unknown to me. This arrangement could be used to quickly discover the optimal dwell time empirically. 🙂
Re: Enclosure w/ filtration for printing ABS indoors?
I have done some fume extractor for solder
1) https://www.facebook.com/pg/PTRTECH/photos/?tab=album&album_id=337728380044675
2) https://www.ebay.co.uk/itm/Solder-Smoke-Absorber-Fume-Extractor-Air-Filter-Purifier-for-Soldering-FE140A/183201678207?hash=item2aa7abc37f:g:4V0AAOSw4J5a5gel
About your deep levels, 18" is overkill = 45.72cm, my tip is start low levels, test and grow if needed. eg: test with 2.5", 3", 4" and stop when is good.
For deep levels you need a very power fan or multiple fans, eg: Place one fan at each 2.5" depending on fan power, but your sound levels will increase a lot, to be silent you need double your fan number and go with low rotation fans, or even better, PWM them.
Proper filters are very expensive and big, eg: https://www.ersa-shop.com/ersa-kombifilter-partikelfilter-gasfilter-aktivkohle-f%C3%BCr-easy-p-12035.html
Note: HEPA and or carbon mesh alone does nothing, you will need multiple combinations.
I'm still testing my filter system, i will write when i got more results, and i may design a new version fully capable
Re: Enclosure w/ filtration for printing ABS indoors?
Your fume extractor makes reference to using a "cold catalyst" as the final stage. What is a cold catalyst, and are you using one?
Re: Enclosure w/ filtration for printing ABS indoors?
Your fume extractor makes reference to using a "cold catalyst" as the final stage. What is a cold catalyst, and are you using one?
That is described on the picture, read:
Re: Enclosure w/ filtration for printing ABS indoors?
Uh, right. It was that picture that prompted me to ask the question. I just didn't see it in your parts listing like I did the other parts.
Re: Enclosure w/ filtration for printing ABS indoors?
In any case, I found a new particle sensor, this one made by Honeywell. It costs only slightly more, but what really sets it aside in my mind is that it claims to be fully calibrated: https://www.honeywellscportal.com/honeywell-sensing-hpm-series-particle-sensors-datasheet-32322550-e-en.pdf For that reason alone, plus maybe Honeywell's brand reputation for quality, I'm picking it over the others.
I'll get mine through Digikey, but for those who prefer Aliexpress, you can get it there also: https://www.aliexpress.com/item/PM2-5-sensor-HONEYWELL-HPMA115S0-XXX-laser-pm2-5-air-quality-detection-sensor-module-Super-dust/32829242280.html?spm=2114.search0604.3.1.daba2b5cOi3FJ1&ws_ab_test=searchweb0_0,searchweb201602_2_10152_10065_10151_10344_10068_10130_10342_10547_10343_10546_10340_10341_10548_5724715_10545_10696_10084_5724015_10083_10618_5724315_10307_5724215_5724115_5013713_10059_100031_5725015_10103_5724915_10624_10623_10622_5013813_10621_10620,searchweb201603_45,ppcSwitch_7&algo_expid=573a1c4e-45c0-4817-84ce-2066e947bb9a-0&algo_pvid=573a1c4e-45c0-4817-84ce-2066e947bb9a&priceBeautifyAB=0
There are a number of libraries on github for interfacing with it.
Re: Enclosure w/ filtration for printing ABS indoors?
In any case, I found a new particle sensor, this one made by Honeywell. It costs only slightly more, but what really sets it aside in my mind is that it claims to be fully calibrated: https://www.honeywellscportal.com/honeywell-sensing-hpm-series-particle-sensors-datasheet-32322550-e-en.pdf For that reason alone, plus maybe Honeywell's brand reputation for quality, I'm picking it over the others.
I'll get mine through Digikey, but for those who prefer Aliexpress, you can get it there also: https://www.aliexpress.com/item/PM2-5-sensor-HONEYWELL-HPMA115S0-XXX-laser-pm2-5-air-quality-detection-sensor-module-Super-dust/32829242280.html?spm=2114.search0604.3.1.daba2b5cOi3FJ1&ws_ab_test=searchweb0_0,searchweb201602_2_10152_10065_10151_10344_10068_10130_10342_10547_10343_10546_10340_10341_10548_5724715_10545_10696_10084_5724015_10083_10618_5724315_10307_5724215_5724115_5013713_10059_100031_5725015_10103_5724915_10624_10623_10622_5013813_10621_10620,searchweb201603_45,ppcSwitch_7&algo_expid=573a1c4e-45c0-4817-84ce-2066e947bb9a-0&algo_pvid=573a1c4e-45c0-4817-84ce-2066e947bb9a&priceBeautifyAB=0
There are a number of libraries on github for interfacing with it.
You also can go with Pi if you already using, that guy post about that: https://shop.prusa3d.com/forum/user-mods-octoprint-enclosures-nozzles--f65/my-handmade-enclosure-for-prusa-t23384-s10.html#p102821
My guess is go with any monitor, they will do the same, what matter is how you fell near the fumes and invest more effort to filtering, you don't need a monitor at all when filtering is working properly
Re: Enclosure w/ filtration for printing ABS indoors?
I've ordered the SGP30 and the BME680 sensors to measuring TVOC. Hopefully one or the other will be sensitive to any VOC's that might be emitted by the printer during printing.
If anyone has any suggestions on a better sensor to try, please post and I'll try that too.
Re: Enclosure w/ filtration for printing ABS indoors?
I'm guessing this is in ballpark for more of a commercial grade, non-DIY solution:
https://www.amazon.com/Soldering-Fume-Extractor-120V-Safe/dp/B0053PR4G0/ref=pd_sbs_328_2?_encoding=UTF8&pd_rd_i=B0053PR4G0&pd_rd_r=53e10ca8-a4df-11e8-8d50-035ba98a04ea&pd_rd_w=vInUk&pd_rd_wg=dB9Kd&pf_rd_i=desktop-dp-sims&pf_rd_m=ATVPDKIKX0DER&pf_rd_p=ebf3f80b-3878-4fb9-8381-bbec92f92693&pf_rd_r=VPRP4D0Z3TGV4KK3BYAY&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&psc=1&refRID=VPRP4D0Z3TGV4KK3BYAY
For what it is, it seems surprisingly expensive. Yet, competing units cost about the same:
http://www.testequipmentdepot.com/weller/fume-extraction/volume-extraction/zero-smog-el-fume-extraction-unit-kit-120w-120v-zerosmogelkit1.htm?ref=gbase&gclid=CjwKCAjwzenbBRB3EiwAItS-u4JtZsRvNaJO-8BqTvnuaPCtTTlmytu0_WSPvCmqRnkcMF86bNaQExoCv0UQAvD_BwE
Re: Enclosure w/ filtration for printing ABS indoors?
Yes comercial fume extractors are very expensive!
Thats why i build myself
eg: https://www.ersa-shop.com/ersa-filterger%C3%A4t-easy-schnittstelle-f%C3%BCr-icon-vario-p-12021.html
That not include the tube nor head!
Re: Enclosure w/ filtration for printing ABS indoors?
Yes comercial fume extractors are very expensive!
Thats why i build myself
eg: https://www.ersa-shop.com/ersa-filterger%C3%A4t-easy-schnittstelle-f%C3%BCr-icon-vario-p-12021.html
That not include the tube nor head!
Agreed. The least expensive one I've found so far is this one:
http://www.testequipmentdepot.com/metcal/fume-extraction-systems/bench-top-systems/bvx-100-series/bench-top-plenum-pre-gas-gas-fume-extraction-system-bvx105.htm
which uses $80 filters:
http://www.testequipmentdepot.com/metcal/fume-extraction-systems/accessories/filters/deep-bed-gas-filter-fgbvx.htm
However, there's no way of knowing in advance whether those filters would be adequate for cleaning the air in one-pass out of a 3D printer enclosure. You might get lucky, or you might not. That's why, in this case, a DIY filter design has advantages: namely, you can keep improving it until it is good enough.
Re: Enclosure w/ filtration for printing ABS indoors?
At the low end of the spectrum, this is maybe (?) the barest minimum of what might be needed for a fume extractor from a 3D printer enclosure: https://www.instructables.com/id/Active-Air-Filter-HEPA-13-Filter-and-Active-Carbon/
Looks fairly inexpensive and easy to assemble.
Re: Enclosure w/ filtration for printing ABS indoors?
At the low end of the spectrum, this is maybe (?) the barest minimum of what might be needed for a fume extractor from a 3D printer enclosure: https://www.instructables.com/id/Active-Air-Filter-HEPA-13-Filter-and-Active-Carbon/
Looks fairly inexpensive and easy to assemble.
Yes that easy and cheap to build, but i think will not be effective with ABS.
You need more carbon deep
Re: Enclosure w/ filtration for printing ABS indoors?
I had an idea for a filter construction; I will try to make a design drawing later (quite busy now), but the idea would be to use 4 fans and use the fan speeds to determine if you want to have the air directed into the enclosure or to the outside. The side view would be like this:
____________________
-> F1 F2__________: -> to outside
F1______F3_ \_/ _F4 <- intake fan
\ | / |
inside | | | outside
| | |
to inside <-'
F1 is an intake fan that pushes air in the filter assembly (could contain active carbon and hepa, this construction is more about the airflow than the filtering in itself); ideally this assembly is accessible from the top for ease of replacing the filters. F1 is bigger than the other fans, does not really matter as long as the airflow is matched correctly (I need some surface area to put both F2 and F3, so rather than changing the shape of the cross section, I decided that putting a bigger fan is a possibility).
F2 is a fan that pulls air out of the filter and directs it outside
F3 is a fan that pulls air out of the filter and directs it inside
F4 is a fan that pulls air from the outside to the inside
Filter is between F1 and F2/F3, this could be made as long as necessary.
There are constraints:
F4 is probably overkill, and may possibly be replaced with some one-way mechanism that only allows air to be pulled in. I've put F4 for now on the diagram as it gives more control. Either way it should always be slow enough not to create an overpressure (as this would push dirty air out of the cabinet through the edges - it is not a hermetically sealed cabinet). The one way mechanism may help for that, but may limit circulation of fresh air and there may not be enough of a pressure difference to open it (but maybe that does not matter, air will get in). Still, that is why I put F4 for now (it does not complicate much).
Extreme case 1:
F1 = F2 =F4; F3=0: air is forced through the filter and forced outside, fresh air it taken in. I think F4 should be slightly less than F1 and F2 to keep underpressure in the enclosure. It may be necessary to set F3 slightly more than 0 (and adjust F4 accordingly) to be sure no air escapes the filter in the wrong direction. Some hot air will get recirculated, but it will be limited, at least the air that is pushed outside will have passed through the filter.
Extreme case 2:
F1 = F3; F2=0; F4=0: air is forced through the filter and recirculated into the enclosure. To guarantee underpressure, I think that F2 should be just above 0 and F4 between that value and 0. Some hot air will get out through F2 but it is filtered and at least we control the airflow in all locations.
For a fan controller, this means that F1 can be constant, F2 and F4 increase/decrease together and F3 increases/decreases inverse compared to F2. Using an Arduino, it should be possible to control the fans based on a set temperature in the enclosure. The Arduino could generate a PWM pulse for each of the fans; when you use 4 pin fans (common in PC cooling), connecting this pulse to the control pin of the fan makes it easy to adjust the speed. The fans also return a tach-signal; this could be connected back to the Arduino for monitoring purposes.
If you don't want to venture into Arduino stuff, some drive bay mounted PC-fan controller could be up for the task: it should allow you to set the speeds of the different fans manually (e.g. Lamptron FC5, it uses voltage control so no need to get 4 pin PWM fans but the minimum speed of a voltage controlled fan is higher). At the moment I'm unable to make it (and it will be a bit of time before I will be able to), but I want to throw the idea in here. I'm not an expert in fluid dynamics, so this is all a bit based on my experience with PC cooling, a bit of a different problem as there you want to get the heat out of the enclosure (and preferably as silent as possible). I would get started on the Arduino thing, just to see what is possible.
Other variants for the design are possible (e.g. move the intake fan lower), but the drawing is more to show the concept of using fans to determine amount of recirculation. If there is validity to this concept, the design can be refined further to suit the enclosure.
Questions are:
Could this work?
Is there a point to this?
Re: Enclosure w/ filtration for printing ABS indoors?
I couldn't quite follow that. It sounds like you're using 4 fans in place of 1 variable speed fan. Is that the main idea?
Re: Enclosure w/ filtration for printing ABS indoors?
The main idea is to come up with a filter assembly in which an automated control of heat recycling is possible; I wanted to avoid mechanical constructions to direct the air and figured it may be possible with fans alone. I also wanted to avoid having two separate assemblies for recirculating air or for venting air. The reason that I combine it with the filter is that the filter sort of doubles as the blockage between both paths: one path that takes the air out, a second path that recirculates the air.
The core idea is basically (the outline is the enclosure):
__________________________
| -> F1 F2___->__: ->
| F1______F3 -> |
| |
| printer |
|__________________________|
Air will not flow easily through the filter, having two separate fans that extract the air from it allows some control on where the air exits the filter: either mainly via fan F2, either mainly via F3, or via both in some mixture. This is the reason why "flowrate of F1= flowrate of F2 + flowrate of F3": whatever gets pushed in by F1 gets extracted by one of the two fans F2 and F3 and not much will exit via the other path (unless both fans are in operation). I added F1 to draw air in (may not even be necessary) and ducted the air from F3 down so that air is more circulated.
Basically, there is a fan (F1) that pulls air into the filter (horizontal part between F1 and F2/F3). Then, there are two fans that extract air from the filter(F2 and F3). One of these (F2) directs the air to the outside (straight path to the back of the enclosure). The other (F3) directs air to the inside of the enclosure (this path goes down). The more air leaves the filter via F2, the more hot air is allowed to exit the enclosure (this is compensated by air coming into the enclosure, eg. via F1, which merges with the path that goes down - not really necessary to merge it like that). The more air is leaves the filter assembly via F3, the more hot air is recirculated.
Allowing air to escape (XX is a disabled fan, in this case F3):
____________________
-> ->____->____: ->
->______XX_ \_/ _<- <-
\ | / |
inside | | | outside
| | |
cold air <-'
Recirculating air (F2 and F4 are disabled):
____________________
-> XX__________:
->__->__->_ \_/ _XX
\ | / |
inside | | | outside
| | |
warm air <-'
By playing with the speeds of F2 and F3, it should be possible to achieve some temperature control (F2 provides cold air, F3 provides hot air), while still filtering the air. The speeds should be such that if F2 increases, F3 decreases and their combined airflow should equal the airflow of F1.
A switched off fan however acts as a grill that allows air to flow in both directions. So this is why I think fans should not be completely disabled and why F1 is there (but the same could be achieved with a one-way vent); but maybe F1 is not necessary at all. The assembly comes at a cost that we let some air escape when we recirculate and we recirculate some air when we want to vent it, in order to prevent the airflow from taking shortcuts we don't want, but I think these effects are limited (it is an argument for PWM controlled fans though, as then it is possible to set the speed very low).
I think this layout may work, but I'm not sure who big the effect is (and if I'm not missing out on some properties of the flowing air that may cause issues with the general idea). If the idea works, then the fact that all control is through fan speeds makes it very easy to automate it.
Re: Enclosure w/ filtration for printing ABS indoors?
1. I do like the idea of being able to control the interior temperature, and that may well involve bringing in cooler air from the exterior of the enclosure to compensate for fast growing heat from the printer.
2. Also, I like the idea of maybe doing some recirculating air filtration during a print, mainly so that there is less to filter out once the print has completed.
3. In addition, maybe (?) there is also an argument for having an interior fan with no filtration too. The idea is the same as a convection oven: maintain uniformity of the air-temp inside the enclosure. Not sure whether this is overkill or instead very smart to do.
So, yeah, I think there maybe might be multiple fans involved in the final version of the enclosure. I imagine the early test versions, though, might be more minimalist. But that's me. Maybe others, such as yourself, would prefer to think further ahead, and that's great if you do.
Re: Enclosure w/ filtration for printing ABS indoors?
I like the enclosure this guy built to silence his CNC:
I too may want to make my Prusa enclosure soundproof to handle the case of overnight prints, where the printer is printing very fast: the faster it prints, the louder it gets.
Since the enclosure should be more or less air tight (so that bad fumes don't leak out), that might make soundproofing even easier.