Heat Flux – What is it in Vaping?
Definition
Heat flux is the rate at which thermal energy flows through your vapecoil every second, measured in milliwatts per millimetre squared (mW/mm²). In simple terms, it tells you how intensely your coil is heating the High VGe-liquid. A higher heat flux means the coil surface gets hotter and faster, producing warmer, denser vapour; a lower value gives cooler, softer Hits. By adjusting Wire Type”>wire type, mass and wattage, vapers can dial in their preferred heat flux to balance flavour, cloud size and coil life.
Technical Details
Heat flux is calculated by dividing the power delivered to the coil (watts) by the coil’s surface area (mm²). Most coil-building apps and Hybrid Connection mods display this value automatically. Typical ranges are 50–150 mW/mm² for mouth-to-lung builds and 180–350 mW/mm² for direct-lung cloud chasing. Variations depend on wire material: Ni80 ramps faster than Kanthal, so it reaches target heat flux sooner. Stainless-steel offers a middle ground and can be used in temperature-control mode to cap heat flux dynamically. If heat flux exceeds the wick’s ability to re-saturate, you risk a Hot Spot and cotton burn.
Usage & Tips
- Start low: aim for 100–150 mW/mm² when testing a new build to avoid dry hits.
- Use a Heatsink or thicker drip-tip if the vapour feels too hot; these pull excess heat away before it reaches your lips.
- Check for even glow: pulsing the coil at low wattage should show uniform colour—no bright stripes—indicating consistent heat flux.
- High-wattage vapers: staggered claptons increase surface area, lowering heat flux per square millimetre while still chucking clouds.
- Safety: never exceed your battery’s continuous amp limit; raising wattage to chase extreme heat flux can stress cells and shorten coil life.
History & Context
The term migrated from thermodynamics into vaping forums around 2014 when rebuildable atomisers became mainstream. Early sub-ohm pioneers used heat-flux calculations to tame 30 A mech mods; today’s chipsets embed the algorithm, letting every Australian vaper tune warmth with a few button clicks.