What actually happens during vapour production

Vapour production is a four-step chain, and each step is governed by heat. When you press the fire button, current flows through the coil and its resistance converts electrical energy into thermal energy. According to Joule heating the power dissipated depends on both current and resistance, which is why a 0.2 ohm coil at 60 W behaves very differently from a 1.2 ohm coil at 12 W.

1. Coil heating. The wire reaches somewhere between 200 and 350 degrees Celsius in a fraction of a second.
2. Liquid vaporisation. E-liquid wicked into the coil crosses its boiling point and shifts from a liquid to a gas phase.
3. Aerosol formation. The hot gas mixes with cooler incoming air and condenses into microscopic droplets, forming an aerosol.
4. Condensation. As the aerosol cools further in the drip tip and the mouth, droplets merge into the visible white cloud you exhale.

If any of these steps runs too hot or too cold, flavour, throat feel, and cloud density all shift. That is where the PG versus VG comparison starts to matter.

PG vs VG: the core comparison

Almost every bottle you find at a UAE liquid shop lists a ratio like 50/50, 60/40, or 70/30. That number is the balance between propylene glycol (PG) and vegetable glycerin (VG), the two base fluids that carry nicotine and flavour. Their physical properties are very different, and that difference is exactly what you are choosing between.

Neither column is objectively better. They are engineered for different draw styles. Boiling behaviour, viscosity, and vapour density all follow from those two numbers, and picking correctly saves you burnt wicks and disappointing flavour.

When to pick a high-PG setup

If you recently moved away from combustible cigarettes, a high-PG blend in a compact pod or MTL tank is usually the right starting point. The lower boiling point means the coil does not have to work as hard, so battery life is longer and coils tend to last more days between changes. That matters in Dubai and Abu Dhabi summers, where indoor air-conditioning is cold but outdoor humidity can drop below 20 percent, drying out wicks faster than you might expect.

High PG also carries flavour with more precision. Bright citrus, mint, and tobacco blends all sing on 50/50 liquid because PG’s small molecule size releases aromatic compounds cleanly at lower temperatures. Sweetness is perceived as focused rather than syrupy, and the throat hit gives smokers the familiar tactile signal they miss when they first switch.

The trade-off is cloud size. If you want the dense plumes you see in vape competitions, a 50/50 in a 1.0 ohm coil will always look modest. That is a feature, not a fault, discreet vapour is exactly what most everyday users want indoors or in shared spaces.

When to pick a high-VG setup

High-VG blends are built for direct-lung sub-ohm devices. You are pushing more power through a lower-resistance coil, so the temperature at the wire climbs higher and the airflow around the coil has to be generous. This is where wattage, coil resistance, and airflow become a tightly linked engineering problem, not just a preference.

Get the balance right and 70/30 or 80/20 blends produce huge, soft clouds with a sweetened, rounded flavour profile. Dessert, custard, and fruit-cream recipes benefit most, because VG’s higher viscosity holds heavier flavour molecules that PG cannot carry as gracefully. Heat distribution across a mesh coil is also more even than on a single round wire, which is why mesh has taken over the sub-ohm category.

The cost is consumables. VG-heavy liquid caramelises on coils faster, especially with sweetened recipes, and coil life on a hard-used sub-ohm tank can be as short as three to five days. You will refill more often and change coils more often, so plan the budget accordingly when you shop.

Temperature, flavour and coil longevity

Flavour perception is not linear with heat. Aroma compounds have their own boiling points, and each one becomes noticeable at a slightly different coil temperature. Push too low and top notes stay locked in the liquid. Push too high and you start cracking the glycerin itself into acrolein and other unwanted breakdown products, which taste burnt and irritate the throat.

The engineering behind the cloud

Four variables control how heat reaches your e-liquid: wattage, coil resistance, airflow, and heat distribution. Materials science research from journals such as aerosol science shows that particle size in the exhaled cloud is largely dictated by how quickly the vapour is quenched by incoming air. Open airflow gives smaller droplets and softer clouds. Restricted airflow gives larger droplets, denser visible plumes, and a warmer draw.

• Wattage sets how much energy per second reaches the wire. More watts means faster ramp-up and higher peak temperature.
• Coil resistance decides how that energy converts to heat. Lower resistance draws more current at the same voltage.
• Airflow controls both the cooling of the coil and the dilution of the aerosol.
• Heat distribution depends on wire geometry. Mesh spreads heat evenly, single round wire concentrates it, twisted or Clapton builds sit in between.

If any of this feels overwhelming, it is worth walking into a physical vape store in the UAE and letting the staff match a device to your preferred draw style. Trying two coils side by side in person teaches more than any spec sheet.

A quick research snapshot

Peer-reviewed thermal engineering work has measured coil surface temperatures using infrared cameras and micro-thermocouples, and consistently finds that keeping peak temperature below roughly 300 degrees Celsius keeps aldehyde formation low while still producing satisfying vapour. That is the practical target modern regulated mods aim for, and it is why temperature-control modes exist on higher-end devices. In short, controlled heating is not marketing, it is a measurable safety and quality lever.