This guide provides some handy guidance on what top and bottom vent settings you should use on your smoker for optimal performance.
Key information
- Generally the rule of thumb on any smoker is 1/3 to 2/3 of the vent opening of what you'd use for manual control.
- The top vent acts like a brake on the system. Without the Smartfire forcing air through the top vent will prevent enough air from top feeding the smoker and slow down the fire.
- Fan should be sitting in the lower range of say 0-40%, any higher consistently after hitting target means that the top vent is a touch too closed. Open it up another 10-20%.
- If the fan is barely ever turning on and the temperature is floating above target, close things down a touch, ie 20%. The fan sitting above 50% is a good sign the top vent is too closed or the fuel is running out! If the fan is sitting on 0-35% that's all good, though if you're going for high temperatures you may well see the fan sitting 40%+
- Maximum recommended temperature is 400F/205C on a bullet/kettle and 450F/230C on a kamado/drum/cabinet. Read below for tips for the bottom vent being open above 300F/150C as an 'escape valve' for when the lid is closed.
Lighting the smoker
- During startup you want the vents to be more open so the fire catches on and burns cleanly until the smoker is approaching target
- Light a clenched fist worth of fuel, or a third of a chimney if using a chimney
- Attach the Smartfire to the vent and close the bottom vent up to seal the adaptor
- Leave the top vent fully open
- Close down the top vent to the setting you'll use for your target temperature when the ambient reaches about ~80% of target. IE if aiming for 225F close down the top vents at 170/180F, if aiming for 275F close it down at 220F. That will slow it down and allow the Smartfire to gently ramp the smoker to target. On metal smokers you may find going for 90% of target before shutting down vents is easier and effective without overshoot.
Kamado & Kettle vent guide
225F / 110C
- Top vent daisy wheel holes ~2mm open
- Bottom vent sealed
250F / 120C
- Top vent daisy wheel holes 5mm open
275F / 135C
- Top vent daisy wheel holes 3/4 open
300F / 150C
- Top vent full open
350F+ / 175C+
- Top vent full open, perhaps daisy wheel pushed to the side 5mm as well
- Bottom vent cracked 4mm to let hot air out when lid closes. Above 400 have it a good 10mm open.
Drum smoker vent guide
225F / 110C (unlikely for a drum, but worth saying)
- Top vent 5mm open, maybe less if the temperature is floating above target
- Other vents closed
275F / 135C
- Top vent 5-10mm open
- Other inlet vent cracked a tiny bit to help even burn of the firebox
300F / 150C
- Top vent half
- Other vent cracked say 3mm to help with even firebox burn and escape valve for air pushed when lid is closed
350F+ / 175C+
- Top vent full open
- Other vent open 5mm to help with firebox burn and escape valve for air pushed when lid is closed