Venting fan strength

I set up my venting (in my garage and have a 4’ exhaust with a fan at the top, venting to the roof. I have this fan set up and when I roasted, it seemed to catch a good amount of the smoke but when I looked behind me, there was more smoke than I’d realized. Should I consider moving the fan closer towards the roaster and further away from the roof or should I just get a new fan that’s a bit stronger?

Based on what I have experienced with a similar fan, I would have to say you are underpowered. For myself and many other on the site, the Cloudline S4 works really well. I used it on my seasoning roasts and had no issues pulling away all the smoke produced going through second crack.
Cloudline S4

Your issue is very possibly insufficient make-up air. If you’re going to move 200 CFM out of the garage, there has to be a source of 200 CFM to replace the lost air. That air has to come from somewhere of the air just isn’t going to move.

Most solve the issue by cracking a window or leaving a door ajar. If it’s cold you’re going to be inclined to cheat a bit but the effect is usually stalled air flow which leaves the the smokey haze behind.

If you’re confident you have sufficient make-up air for what you’re moving out if the garage then it may simply be insufficient extraction flow in the in-line fan.

Btw, be aware that the exhaust fan on the Bullet moves a lot of air at high fan settings.


The Infinity fan moves 106CFM while the Cloudline S4 is a good deal more powerful with a flow of 205CFM. I use a Hon&Guan inline fan which moves 141CFM and it has performed well even with smoke from seasoning roasts. In addition to draw power of fan and source of replacement air (so that your not creating a negative pressure in the room), it’s good to have a hood of some sort over the Bullet exhaust. I made mine from a simple bowl with base cut away and then covered it with aluminium tape which I then connected to the ducting and inline fan.