All of our roasters come equipped with variable airflow. Manually controlled roasters include a dial on the control panel with markings of 0-100 that represents a wide spread of airflow from potentially way too low to potentially way too high. As part of learning to control your machine, it is helpful to establish and use 3 settings:
Don’t get hung up on the dial numbers. Different roaster and batch sizes and venting schemes make precise fan settings impossible to share. Instead, grab a cigarette lighter and watch the way the flame pulls into the tryer port to get an idea of how much airflow your fan is pulling at various settings.
1. Pull out the trier from the trier chute.
All of our roasters include a digital drum pressure gauge to verify airflow numbers. Once you establish optimal low, medium and high setting for various batch sizes, you'll have a drum pressure readout to verfiy that you are actually moving the ideal volume of air through the system for that particular batch size.
If the drum pressure reads low for any given setting, you'll probably need to bump the fan speed to get to your roast air back to "normal" and then plan on cleaning something soon.
Now that we have the settings, how is airflow used? This is how we use airflow when we roast.
It's your roaster and your coffee. You can do things anyway you want, but getting airflow dialed in a very good place to start.