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:
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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.
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Metal duct splitter with 6" fittings and a 4" Y-split for the cooling tray fan
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Metal adjustable elbow
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36" metal duct
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AC Infinity S6 Pro fan
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Small section of flexible hose (about 18")
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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 donāt think smoke is supposed to leak from any point other than the exhaust port.
In addition:
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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.
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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 whatās 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 shouldnāt be necessary as I donāt think that should be an exhaust source.
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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).
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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 Mariaās from which I bought the Bullet R2 Pro back in January 2025 (yes, itās 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 Iāve done all I can and more.