Bottom Airflow – What is it in Vaping?

Definition

Bottom airflow is an air intake design in atomisers where air enters the tank or dripper through holes positioned under the coil and travels upward through or around the heating element before reaching the mouthpiece. This configuration maximises flavour density and vapour production by directing cool air straight onto the coil and wicking material, ensuring efficient heat exchange and rapid vapour formation. Popular with Australian vapers who chase rich flavour and smooth Hit“>throat hit, bottom airflow systems are found in both regulated box mods and mechanical devices. Because the intake slots sit low on the atomiser, they rely on precise build deck engineering and sturdy o-rings to prevent leakage while maintaining a steady stream of air for consistent draws.

Technical Details

Air typically enters through 2–6 adjustable slots measuring 1 mm–3 mm wide, drilled into the base of the atomiser just below the bottom coil or BVC (Bottom Vertical Coil). Negative pressure created by inhalation pulls air upward, forming a vortex that envelops the coil and cottonwick, cooling the assembly and condensing vapour. Variants include:

• Fixed bottom airflow: Non-adjustable holes tuned for mouth-to-lung (MTL) tight draws.
• Adjustable bottom airflow: Rotating ring that opens or closes slots for restricted direct-lung (RDL) or fully open cloud chasing.
• Semi-hidden bottom airflow: Channels routed inside the deck to hide slots from view, reducing leak risk.

Threading is usually 510-standard, and Airflow Control)”>AFC (airflow control) rings are sealed with silicone or nitrile gaskets rated for 60 °C–120 °C to withstand high-wattage vaping.

Usage & Tips

Prime your coil thoroughly before first use; dry cotton will not draw liquid upward against bottom airflow, causing dry hits. Close airflow when filling top-cap tanks to avoid flooding, then reopen gradually to your preferred setting. If gurgling occurs, invert the tank and blow gently through the mouthpiece while firing at low wattage to expel excess e-liquid. Clean intake slots weekly with a soft brush to remove condensed residue that can mute flavour. Always check that o-rings are seated correctly—bottom airflow atomisers are more prone to leakage when left on their side in hot Australian climates. For rebuildables, position coils 1 mm–2 mm above the airflow holes to prevent shorting and ensure vapour spirals upward evenly.

History & Context

Bottom airflow emerged in 2012 when sub-ohm vaping gained traction and vapers demanded cooler, tastier vapour from high-wattage box mods. Early Genesis-style tanks drilled single 1 mm holes beneath mesh coils; by 2015, manufacturers like Kangertech and Aspire popularised mass-market adjustable systems. Today, bottom airflow remains a staple in both budget starter kits and high-end Australian rebuildables, continually refined by CNC machining and computational fluid-dynamics modelling to balance flavour, cloud, and leak resistance.