@ibnabouna, you’ve already gone above and beyond, and it really stinks (literally) that you’re dealing with this issue. If you want to be extra cautious, you could set up a tabletop chemical fume hood—something that creates a negative air environment to pull fumes away, like they use in labs. But honestly, that might be overkill for coffee roasting, not to mention expensive.
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Thank you, @onogrinds, yes, I was actually thinking something similar yesterday. I didn’t know there is a specialized hood for chemicals, but I was thinking of doing a proper kitchen hood installation above the roaster and ducting 6" from that. I could remove the second AC Infinity fan above the roaster and use the built-in fan of the hood to suck up the air from a larger area. I’m hesitant, though, because that would be at least another few hundred dollars and there is no guarantee it would work. I still don’t understand why the existing setup doesn’t work if:
- It has two fans pulling air at 407 cfm each.
- There are no obvious leaks in the ductwork, or at least I’ve taken care of what I found.
- The duct boot fully covers the exhaust port of the roaster.
- There is strong air blowing outside through the vent hood.
- I have an open window behind me.
Today, I tried a couple of new things at my wife’s suggestion. First, she recommended I place a fan behind me to suck air from the open window and blow it towards the ducting to ensure there is negative pressure. I placed an industrial-grade AirKing fan and it did a great job circulating fresh air from the window in the room.
Second, I cleaned the impeller fan and exhaust port thoroughly to like-new condition. I had planned to clean the roaster every 50 roasts anyway since my regular batch is about 600g, so it was a good chance.
With the new circulation and clean fan/exhaust port, I did another 600g roast of a Crown Jewel Peru. Both AC Infinity fans were at the maximum Level 10 speed for this.
It did not go well. Still HAZARDOUS levels on the monitor. But this time, I recorded a video so that others might see and perhaps tell me if I am doing something wrong. You can view it here (it’s about 300mb). I apologize for the low lighting and sometimes jittery hand motion. I was wearing a full respirator to be able to stay near the roaster and record.
Do you see anything obvious?
Edit:
I should add that, prior to the beginning of the video, I was not wearing the respirator and was sitting in the room with all the fans turned on while the R2 Pro was preheating. The PM2.5 number was at 6 and the PM10 was about 12. The air quality was labeled GOOD. It was only after a couple of minutes into the roast that the label changed to MODERATE and I had a good idea where this was going based on previous roasts, so I put the respirator on and started recording.
The video also gives you a glimpse into the outdoor vent hood where the air is blow out. You can see the plastic anti-critter grate is convex from the force of the air coming out of it.
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As I and a few others have said, it would be difficult to survive without some special gear at those levels. Certainly, none of the things we see in the video would be visible. That being said, at around the 4 minute mark, when FC is rolling, I think I can see some smoke in front of the roaster. That I will attribute to a poor seal where the trier should be, and it would be enough to trigger all this chaos. Not sure about such high levels, so I would place some blame on the meter, but I think the smoke is coming from the front, so look there and keep in mind my money is on a leak from the trier hole.
My comments are based upon experience with the R1 so you need to pick thru to find the similarities.
If smoke is coming from the front it’s a good indication there are restrictions in the exhaust path for the fan speed chosen. One possibility is that the exhaust fan isn’t operating at sufficiently high revs to move the exhaust before it leaks out between the bottom of the dump door and the body of the roaster. Easy enough to increase fan speed. But of course that will affect your roast as the fan is removing not only smoke but heat as well.
An alternative I see is to increase the air exchange in the room so that air is exchanged at a faster rate than contaminants are released during the roast. There’s still going to be roast ‘smoke’ around the roaster but it will be carried away. And, of course, there’s always the use of a respirator mask vs. a disposable paper ‘surgical mask’. The paper mask has been my choice… the respirator is more than I can deal with (I’ve tried it).
Bruce
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Yes, these are all valid points when there are no holes from which the smoke can escape, such as trier and the silicone plug on top. Remove one of those and you’ll disrupt the air flow and some smoke is bound to come out. Let’s wait and see where it’s coming from.
In addition to the trier and the charging port, there’s also some exhaust air flow at the bottom of the door. That intentional opening is required in order to allow chaff to discharge into the cooling tray. I roast pretty dark and usually see some small amount of smoke there as I get into 2C. A lot of that smoke is collected thru the grilled opening at the base of the control panel pedestal then past the IR sensor and into the roast chamber to be mixed with the rest of the exhaust. You might not notice it’s happening unless you roast to a dark stage.
And yes, removing the charging plug or the tryer disrupts the air flow.
And of course I’ve presumed here that R1 and R2 roasters share these design features.
Bruce
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I can’t add to what has already been said but I love the prayer book under the monitor. 
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If you’ve been following all the issues, you’ll understand why the prayer book is necessary. 
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Don’t tell me you performed an exorcism on the Bullet Abouna. 
It seems like we’re heading in that direction.
The latest update is that, after cleaning the impeller fan, I decided to also remove the front panel and control module to clean beneath and inside the drum. To my surprise, I found quite a few beans here:
My best guess is there was a jam while charging a batch and a good amount of beans (10-20g) were deposited there. Based on that, I reasoned this might have been the cause of the excess smoke, because these beans were getting heated without any movement or airflow.
I put everything back together and just tried another roast. Unfortunately, it was the same HAZARDOUS result. Cleaning the drum and behind the front panel didn’t make any difference.
Also, based on the suggestions above, I removed the silicone tube/mic and replaced it with the trier, which I didn’t use throughout the roast. It didn’t make a difference, sadly.
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Oh well, in that case I’d only blame the AQI monitor. It is impossible to have over 500 and survive in such a small room. Here is how it looks like in a much larger room, which is called India.
I see it as an impossibility that anyone could survive over 500 in a small room such as yours. At the very least a medical team would have to intervene and give you oxygen and maybe attach you to a respirator
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I still think the way the ducts are bending is creating too much back pressure. It happened to me. When I took a flashlight and held it up near the exhaust intake I could see the smoke being puffed back towards the roaster, and it was really bad when I dropped the beans, no matter how much fan I used. When I adjusted the path of the ducts so that I had fewer, smaller angles it went away completely.
Raising the filter box to get rid of at one angle would reduce the back pressure. It would be even further reduced if the duct made a straight line to the exit, on the diagonal. The exhaust port on the outside forces the air down and that may be contributing more back pressure as well. I had an exhaust cover like that one but I removed it and it instantly reduced the smoke coming back in, especially when it was extremely cold outside. The things others have mentioned also helped me a lot (fresh air intake, away from exhaust, get rid of filter box and any other things restricting airflow) but the biggest impact was the path of the ducts. At least for me anyways.
Now I am with using one 4” fan and 4” ducts on a run that is quite a bit longer than this one, without any smoke filling the room. The coffee roasting smell doesn’t linger much longer than cooking in my kitchen does. It took a lot of time to figure out and that’s no fun, but it was better than the alternative of throwing money at the problem.
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Thank you for that. I’ll work on the ducting, perhaps using metal Type B ducts in a straight line without the filter.
In the meantime, I bought a ramp and 220v extension cord to roast a few batches outside. It worked well, though the air quality monitor reported a few seconds of UNHEALTHY when the wind blew some exhaust in its direction. Most of the roast was GOOD or MODERATE on the monitor.
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Hello all,
I’m following this topic carefully. It seems that there are lots of things to learn. I got my Bullet pro few weeks ago and did 5 roasts so far (mainly the seasoning ) . I’m roasting indoor and had so much smoke all over the area I’m roasting in. The alarms went off and took forever to stop. The smell still lingers even though it’s been over a week. I’m really nervous to roast again. I thought I had a good set up but apparently it is not. I had posted a picture before under another username and just updated the username today.
I’m gonna keep following this post and see what the final recommendation is. This is really a great community, and everyone is trying to help one another. Thank you all.
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With seasoning, it is impossible to get the smoke out. You must do it with all the windows wide open and have good neighbours. As for your setup, I don’t think the impeller alone is enough to push the smoke through. You must add an extractor fan and you should be good. I have something similar, but my fan just brings the smoke to the range hood which then expels it. No smoke whatsoever.
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I’ve said this several times above, but it’s worth repeating. Get an air quality monitor that you trust for the room with the roaster. No need to take chances with your long-term health just to roast coffee. An accurate monitor will show you what’s going on with your air and help you understand what you need do to mitigate the hazard.
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Thank you braca for your feedback. I have a SUNCOURT 6-in dia 250 CFM Galvanized steel Axial duct fan on the top (that’s where the duct tube is connected to. I’m thinking to buy one of the two below items with a filter box, but I’m not sure which one to buy. If you or anyone else has any recommendation that will be great.
( AC Infinity Air Filtration Kit 6”, CLOUDLINE LITE Inline Fan and Carbon Filter Combo, Cooling and Ventilation System for Grow Tents, Hydroponics, Indoor Gardening)
or the ( VIVOSUN Smart Air Filtration PRO T6 Kit 6", AeroZesh T6 Inline Duct Fan w/GrowHub E42A Temp. Humidity WiFi-Controller, Carbon Filter & Ducting, Cooling & Ventilation System for Grow Tent, Hydroponics)
Both of those filters would need to be on the outside, because you’d be enveloped in a cloud of smoke if you place them inside the room where you’re roasting. They are good for grow tents, but not for roasting coffee indoors. When you place them on the outside, the active carbon will filter the smoke, reducing odour if you’re concerned about what your neighbours might say. This is because all the setup ends with the filter and doesn’t take the smoke outside but just filters it, so you end up with a room full of filtered smoke. They are not particularly sustainable, as you’ll need to replace them often, or reactivate the carbon. To be completely honest, I wouldn’t place any kind of filter on the inside, except those range hood filters that are similar to the one that you may find inside the cooling tray. Usually, the stainless-steel mesh range hood filters do a pretty good job of holding on to greasy and chunky stuff. The main task is to expel smoke as quickly as possible, so any filtration in the path would hinder that a little bit.
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Thank you ibnabouna, I looked at a post you had previously and there were two monitors that you posted so i wasn’t sure which one to choose from or if I need to buy the both of them. Would you mind sharing which one/ones to buy?
braca, so, I’m not worried regarding complaints from the neighbors, then you think it would be safe/okay, not to even put filters? There is a huge gap between my house and the neighbors and I don’t even think the smoke can even reach them. Also, if I replace the suncourt 6-in dia 250 CFM fan with a range hood that has a stainless steel filters (with maybe 380 CFM or more) along with the cloudline fan (where a ducting tube connects the roaster to the couldline fan from one side, then have another tube connects from the other side of the cloudline to the hood range, would this be a good idea?
AC Infinity CLOUDLINE PRO T4, Quiet 4” Inline Duct Fan with Temperature Humidity VPD Controller, WiFi Integrated App Control - Ventilation Exhaust Fan for Heating Cooling, Grow Tents, Hydroponics
sorry for the miserable sketch
