Hi @ibnabouna . I’m following this company and bought a device from them few weeks ago.
They came up with a new device to clean the air from smoke. I haven’t tried/tested it yet. Below are some videos about the device. Maybe this could be a solution.
I’m going to the SCA expo next week in Houston and they will be there. I’ll check it out and let you know my thoughts.
We had some discussions at Aillio and have analyzed the design and done some tests.
For testing, we adding a tube from the cooling vent through a pipe to a PM meter.
The readings did not increase during roasting.
I took apart an R2 this morning to see if anything looked out of the ordinary.
As each part of the roaster is not sealed air tight against one another, air could potentially escape between the inner front plate and the drum, down where some of the chaffs are expelled during roasting. This smoke could be sucked between the chassis and plastic leg, through some openings in the induction frame and then out by the blower. However, I don’t see any evidence of this being the case on our R2 which have roasted a lot of coffee. There is no dust or particles on the aluminum.
The cooling fan gets the air from the whole bottom part of the R2. Therefor, any smoke around the roaster could be sucked into this filter and out the coil blower. You can take off the bottom filter and easily see where it is dirty.
Not sure how much airflow you are setting, this could impact how much back pressure you have and higher flower would in theory prevent more air from escaping around the door and trier (which are also not 100% airtight).
Of course it is important to keep the cooling tray sealed as much as possible, as smoke underneath the R2 would be sucked through the electronics and out the cooling vents.
One more link about this product
https://www.instagram.com/p/DIWhL3Cv_q6/?img_index=5&igsh=cHFtODVseTZrNnNm
I don’t like that they say it is compatible with the Bullet as they have never tested it - I know this because we are in talks with them about testing.
Most catalysts can be good when the smoke is hot, but will not work effectively at the beginning of the roast, unless you preheat the air cold air before it reaches the catalyst.
Thanks much for the heads up. I was planning to buy one at the SCA EXPO Texas next week. I’m going to hold off for now.
You need a more precise tool to find the leak, e.g. lighter, soapy water, smoke pencil, ultrasonic leak detector, flashlight in the dark, and a big bag of cheap beans you can take well past second crack. The in-line air filter after a fan seems like a potential problem also.
Hey everyone,
I am back to provide an update on this issue, since I was busy with Holy Week and Easter previously and could not do much about it.
TLDR: My Bullet R2 Pro is definitely leaking smoke through the induction fan on the left side. I am now seeing warranty repair.
Updates to the Ventilation Setup
After reading all the helpful comments and tips by others here, I decided to get rid of as much flexible hosing as possible and focus on rigid metal ducting. My setup is now comprised of the following components from the roaster up to the vent:
Vent hood over the exhaust port of the Bullet. I also have the 3D-printed adapter installed on the exhaust port to help direct the smoke up into the vent hood.
Metal duct splitter with 6" fittings and a 4" Y-split for the cooling tray fan
Metal adjustable elbow
36" metal duct
AC Infinity S6 Pro fan
Small section of flexible hose (about 18")
Semi-rigid aluminum elbow connected to the vent hood w/ damper termination to outside.
I forgot to take a photo, but will do so shortly. Hopefully this description makes sense. In essence, it is a 90% metal construction with each piece securely fastened and confirmed to have no leaks.
New Air Purifier
In addition, I placed a new Levoit Plasma Pro Core 300S Smart Air Purifier next to the roaster. This runs at full blast during roasting.
First Test with New Setup
Optimistic about this new setup, I just tried an 1100g roast, which is my usual batch size. Everything was promising at the beginning with the PM 2.5 levels at GOOD until dry end. From there, they followed the same progression as when I had flexible hose. The particulate levels begin to elevate at dry end and then really shoot up into HAZARDOUS territory on the monitor around first crack until the end of the roast.
I marveled at why the smell of the roasting coffee was so strong in the room during the roast and decided to position the AQ monitor directly in front of the induction fan at the left side of the roaster. Sure enough, when it was positioned there, the numbers rapidly increase, but when I removed the monitor to its usual position, it tapered down a bit.
This leads me to the conclusion that the problem is not my ventilation setup, especially this new one with metal ducting. The problem is smoke leaking from something other than the exhaust port. This points to a problem with the Bullet R2 Pro itself, because I don’t think smoke is supposed to leak from any point other than the exhaust port.
In addition:
The problem is not airflow or makeup air in my setup, because I have both a window and door fully open behind me letting in plenty of air for the AC Infinity fan to do its job.
The problem is not the AC Infinity fan, because it is pushing a lot of smoke out through the vent termination outside. Also, at one point, I had TWO S6 Pros working in tandem, but the result was the same. My fan is sufficient and is doing a great job. The issue is that it is venting what’s coming out of the exhaust port of the roaster, which is a lot, but not the only source of smoke. I suppose I could add another 4" Y and put a duct boot in front of the induction cooling fan to vent that smoke, but that shouldn’t be necessary as I don’t think that should be an exhaust source.
The problem is not the exhaust fan of the roaster. I confirmed that it is working well and responding to different fan speeds (F2-F12).
The problem is not the Temtop Air Quality monitor. Even the built-in monitor on the air purifier reports high PM 2.5 numbers.
Next Steps
This thread has been viewed and discussed quite a bit, especially by prospective owners who reached out to ask about my experience. Many people have done their best to offer suggestions and help, and I have likewise done my best to try whatever was suggested.
In light of this, I plan to contact Sweet Maria’s from which I bought the Bullet R2 Pro back in January 2025 (yes, it’s only 4 mos. old) and Aillio to figure out what needs to be done under the warranty. I have not only followed the recommendations for ventilation from the R2 Pro manual, but also spent a good deal of time and money on additional things (like metal ducting, air purifiers, filters, adapters, different hoses, extra fans, smoke pens, etc.) to make this work as it should. Aillio specifically recommends against using the Bullet outdoors in their manual, so my expectation that this should work indoors with a proper ventilation setup is not unreasonable.
As always, I am open to more ideas, but at this point, I feel like I’ve done all I can and more.
This was my thoughts as well as I also use a s6 inline fan similar set up without the extras and seems to vent well but need to check with a air monitor as I am definitely concerned and curios now as to how well it vents now. Thanks for bringing this to the attention of others on this forum.
Few things you could consider.
Could try adjusting the shims to get the drum a tad more forward, that should seal this more to the front plate.
From your first posts about the PM2.5 particles your roaster seemed fine up until a point in mid March. Have you done any maintenance / deep cleaning?
After removing the front plate was it put correctly back together?
Any beans stuck under the drum giving off smoke?
As @itspaul suggested, a strong flashlight in the dark might help seeing where the smoke originates from.
Also, what is that thing you got in the tryer port?
Greetings, @jacob,
OK, I will try it tomorrow, God willing.
Yes, I have run through the deep cleaning protocol outlined in Aillio’s R2 maintenance videos since March. It was one of the first attempts to solve the problem, but it didn’t make a difference.
I believe so, but I will confirm after adjusting the shims tomorrow. As of now, everything seems to be put together according to spec.
When I last performed the deep cleaning around 2-3 weeks ago, I vacuumed the inside of, and under, the drum very well. One of my posts above shows there were beans stuck above the drum, but nothing was under the drum. Either way, I vacuumed everything 2-3 weeks ago and have been very careful when charging beans ever since.
I actually tried that earlier tonight. Nothing seemed obvious to me, but moving the monitor around suggests the source is around the induction fan at the bottom left of the roaster. That is where the smell is strongest and the monitor shows an increase in particulates rapidly.
Here is a video that shows the particulates increasing quickly after pointing the air quality monitor at the inducting fan at the bottom left of the R2 Pro.
This is a heat-resistant silicone tube snugly inserted into the trier port with a little microphone snugly inserted at the other end. The mic goes to a small USB speaker, which allows me to hear first crack more easily. This ingenious idea comes from @billc and has been discussed on this forums elsewhere. I can assure you, however, that both ends are very snug and no smoke is escaping from the trier.
Lastly, here is a photo of the new setup with almost all metal ducting.
As I took this photo, I was testing something new: putting a small 4" duct boot right next to the induction fan on the bottom left of the roaster. While it did not entirely fix the issue (the air quality still degraded from dry end and ultimately reached UNHEALTHY by the end of the roast), I do feel it helped keep the numbers lower than before. I need to test more tomorrow and record actual values.
I hope this helps in finding a solution soon. Thank you
Hi @ibnabouna ,
I just did a roast today with my setup (see attached). I had the CO2 monitor the whole time from biggening to end. (I have the Bullet Pro). The CO2 level never went over the 600 mark the whole time. So, for me it is working well. As mentioned previously, I have the 3 D print exhaust, so I’m not sure if this is contributing to anything, but thought I’d still mention it.
All the best
That’s great news! I’m glad someone is able to use the machine without concern. Out of curiosity, does your monitor measure PM 2.5 or just CO2? I’m trying to figure out how those correlate.
Thank you. No, I don’t have the PM 2.5 (I don’t know what this is? If it is important, then I would return the device I have and buy another one that has the PM2.5).
I see that I have hPa (no idea what this is). It is at 986.
From Google AI:
PM2.5 refers to fine particulate matter in the air, defined as particles 2.5 micrometers or less in diameter. These tiny particles can be inhaled and cause health problems, especially for vulnerable groups like children, older adults, and those with heart or lung conditions.
More Information:
PM2.5 is a mixture of tiny particles and droplets in the air, including organic chemicals, dust, soot, and metals.
Exposure to PM2.5 can lead to various health issues, including respiratory problems, heart disease, and even premature death.
PM2.5 particles can be inhaled and travel deep into the lungs, where they can enter the bloodstream.
Common sources include vehicle exhaust, industrial emissions, wood burning, and wildfires.
hPa stands for hectopascal, a unit of atmospheric pressure
Yes, what @billc said. Because roasting coffee produces smoke with all kinds of particulates, measuring PM 2.5 and PM 10 (the numbers refer to the size of the particulates) is important to make sure that stuff is not getting into your lungs. With time, they can cause serious respiratory and health issues.
This is why I’ve invested so much time and money trying to get my setup in a good and healthy status.
As a further update following your recommendations, here is what I did yesterday.
I removed the face plate and moved the shims of the drum forward to ensure a good seal. In the process, I also vacuumed inside and underneath the drum to the best of my ability. After completing the test, I tried a 600g roast, but no luck; there was the same increase in unhealthy particulates around dry end and first crack.
I purchased another PM 2.5 monitor (a Govee Home from Amazon), which measures only PM 2.5, temperature, and humidity. I figured fewer sensors might translate into higher accuracy. This is now the third monitor I have checking the air quality (1. Temtop Air Quality Monitor, 2. Levoit 300S Purifier, and 3. Govee Home Monitor). During the roast, I found all of them were more or less similar. The Temtop did have much higher values at different points, but the others ultimately caught up and all of them generally showed the same progression of higher PM 2.5 around dry end (~155 ºC) and first crack (~190 ºC).
I watched an Aillio maintenance video about replacing the drum, so I went ahead and followed that procedure to fully remove the drum and inspect underneath it. I found some fine coffee powder (similar to what gets trapped on the face plate and bean chute), but no whole beans. It was a good opportunity to vacuum everything out fully before replacing the drum and putting everything together.
Sadly, in the process of doing all this to troubleshoot my issue, I accidentally dropped the face plate on the table and the screws holding the bean chute broke off. Thankfully, the chute and bean probe are fine; it’s just the screws. I contacted Sweet Maria’s for help in getting those screws so I can reattach the bean chute securely.
Moreover, for reasons unknown to me, the back side of the power plug of the cooling tray just came apart. Nothing happened; it just came apart. The end result is my cooling tray has no power and I can’t use it to cool the beans. I am in contact with Aillio about this, because the Pro Cooling Tray was supposed to be shipped out at the end of March, but I haven’t received it yet. I don’t know if it makes sense to replace/fix this standard cooling tray or wait for the promised Pro version soon.
Either way, it hasn’t been a great experience this week as the roaster is now out of commission and I can’t fulfill orders. In the past, even with the ventilation issue, I had the option of putting on a full respirator and roasting coffee, but now, between the ventilation issue and the broken bits, I can’t do anything.
@jacob , what do you recommend now?
Thanks for the info above. I’m gonna buy it for sure.
I think this is an easy fix that you can do quickly yourself. I understand that you’re still covered by warranty, but the pro cooling tray should get to you, and in the meantime you can get that one working. Maybe you know how, but here’s a link to the thread about it just in case.
What to use as a fan? - Taking Care of the Bullet - Roast World Community
I’m sure you’ll get the necessary help from Aillio, but just thought this might be useful.
Thanks, @braca19452f9m , that is super helpful. Aillio is sending me new power cables and a tutorial as to how I can replace it (kudos to Aillio for the good customer support in this issue), but the suggestions in your thread might help me get back to roasting more quickly.
Today, I continued working on the setup by replacing the very last bit of flex tube with a metal elbow. Now, my ventilation is all 6" metal ducting powered by a 6" AC Infinity S6 fan.
I ran several tests to ensure there was no air leak from the ventilation. Everything is tight and working as it should.
When running a test a few minutes ago with some seasoning beans, the result was the same as before. Around dry end, the PM 2.5 levels shot up to unhealthy levels. I aborted the roast.
At this point, I believe I’ve spent enough time, money, and perhaps health trying to fix this. I give up and would love to speak with someone at Aillio or Sweet Maria’s about taking this roaster back or exchanging it. I am certain fumes are leaking from the roaster itself when they shouldn’t. It’s not healthy or usable.
