Duct – What is it in Vaping?

Definition

A duct in vaping refers to the internal airflow channel or tube that directs vapour from the coil or heating element to the DripTip“>drip tip or mouthpiece. Found in nearly every vape device—from disposable vapes to rebuildable atomisers—the duct’s primary purpose is to streamline airflow, cool the vapour, and concentrate flavour before it reaches your lips. In pod systems and tanks, the duct is usually moulded into the chimney or centre post, while in rebuildables it may be a separate sleeve or chimney section. A well-designed duct balances restriction for either direct-to-lung (DTL) or mouth-to-lung vaping styles.

Technical Details

How It Works

The duct creates a sealed pathway between the coil and the drip tip. When you inhale, air enters via adjustable or fixed intakes, passes over the coil picking up vapourised e-liquid, then travels up the duct. Internal diameter typically ranges from 2 mm (tight MTL) to 8 mm (open DTL). Many modern tanks use tapered ducts—wider at the coil, narrowing toward the drip tip—to preserve flavour density and reduce turbulence. Some high-end atomisers feature interchangeable ducts or “chimneys” machined from stainless steel or ultem, allowing users to fine-tune draw and temperature.

Common Variations

• Fixed ducts: moulded into disposable vapes and closed pods.
• Adjustable ducts: threaded inserts or rotating sleeves in rebuildables.
• Dual-duct systems: separate channels for dual-coil builds, ensuring balanced airflow to each coil and preventing dry hits.

Usage & Tips

• Cleaning: Rinse the duct under warm water weekly to remove condensation and e-liquid residue; dry thoroughly to avoid spitback.
• Leak Prevention: Ensure o-rings sealing the duct are intact; worn rings let juice bypass the duct and flood the airflow.
• Draw Adjustment: If vapour feels too warm, try a wider-bore duct insert or raise the coil slightly to increase distance from the duct entrance.
• Safety: Never enlarge the duct with drills—this can destabilise airflow and overheat the coil, risking a Hit“>dry hit.

History & Context

Early cig-a-likes had simple plastic ducts barely 1 mm wide. As sub-ohm and DTL vaping gained traction in 2014-2016, manufacturers introduced wider, smoother ducts and modular chimneys, setting the stage for today’s versatile rebuildable atomisers and high-performance disposable vapes.