Bullet R2 Pro - Venting for Permanent Installation

[pinog]

Hi everyone,

I’ve been a long-time lurker here, and now that things are finally getting moving, this is my first post.

I’m currently working with a chimney / HVAC specialist to build a proper, permanent ventilation system for my roastery in Germany, and I’d really appreciate some input from the community before we finalize everything.

I’ll be running an Aillio Bullet R2 Pro alongside a bigger production roaster.
The roastery is located in an industrial estate, so venting directly outside is no problem and has already been authorised by the local authorities.
The installation will be permanent, not a temporary setup, and both the machines will have dedicated ducting.

I’ve found a lot of (sometimes mixed) information online, and after talking with the chimney specialist I’m actually more confused than before — so I thought I’d ask here to get some real-world experience from people who have already gone through this.

My main questions:
• I can exit through the wall in less than the suggested 2.5 m, with a rather gentle 90° angle. In this case, can I get away with a passive system, or is an active system still recommended?
• Can the exhausts — main rear exhaust and bean cooler — join into one single duct before going outside? This applies to both passive and active setups.
• What duct diameter are you successfully using with the Bullet in a fixed installation?
• For the main rear exhaust: are you using adapters to create a closed system, or is your ducting simply “hanging” on the exhaust?
• Any lessons learned that you wish you’d known before installing?

Thanks in advance — I really appreciate the shared knowledge in this community.

Best,
Giuseppe

[secuspec]

An active venting is recommended.
Yes, it can be a single duct with a Y in it. Important here is that the Y should be as close to the wall outlet as possible to prevent turbulence and backdraft when the cooling tray fan is running. Blastgates are optional but, at least in my setup, not required.
The diameter here is 100mm or about 4"
No closed system, just the duct tube above the rear exhaust - optionally and optically more pleasing, with a small hood attached to its end.
Lessons learned: Many ! Such as that my ventury system with a blowing instead of sucking fan did not work and that the easiest and most straightforward solutions work the best.
Another thing you’ll notice is that when dropping the roasted beans into the cooling tray you’ll experience quite some fumes. It can be reduced significantly if you ramp up the Bullets F setting to 12 at the very end of your roast, just two or three seconds prior to opening the flap. And of cause the cooling tray fan must be running.
There are some great examples here in the forum regarding venting options with Cloudline fans.
Below is my solution. It is still ugly but works very well.

[pinog]

Hi Steffen,
thanks for sharing your well-thought-out setup and insights — really appreciate it. I’ll definitely keep that in mind, it’ll help a lot for my next conversation with the chimney specialist.
And great tip about increasing the fan speed right at the very end — I hadn’t thought of that!

Giuseppe