The electrical resistance of a vaping coil is perhaps the most important factor that identifies the coil’s capabilities and describes the type of experience you’ll have when you use it. Resistance – measured in ohms – is a term that describes how easily electricity can flow through a component in a circuit. If a component’s resistance is higher, it restricts the flow of electricity. If its resistance is lower, it allows the current to flow through more easily.

You’ll see the term “sub-ohm” quite often when you read about vaping or shop for vaping products online. The term describes vaping with an atomizer coil that has a resistance under 1.0 ohm. Virtually every vaping kit with a large tank uses a sub-ohm atomizer coil. An above-ohm vaping device, on the other hand, uses an atomizer coil with a resistance above 1.0 ohm. Companies often market above-ohm vaping devices to beginners – but that’s an oversimplification.

As you’re about to learn, the tendency to use a sub-ohm or above-ohm vaping device has nothing to do with one’s level of vaping experience. Many new e-cigarette users begin with sub-ohm devices, and many long-term vapers have no interest in using anything other than above-ohm devices. It’s not your experience level that makes the difference – it’s what you want your vaping experience to be like.
Let’s learn more about the differences between sub-ohm vaping and above-ohm vaping.

The Relationship Between Coil Resistance and Vapour Production

In the early years of the vaping industry, the typical resistance of an atomizer coil was around 2.5 ohms – and the typical e-cigarette generated far less vapour than the vaping devices of today. As vaping increased in popularity, it became obvious that the modest vapour production of the devices available at that time simply wasn’t enough for some people. Vaping product manufacturers worked to deliver more capable devices. At the same time, some vapers began to tinker with building their own atomizer coils from scratch.

Ohm’s Law

Ohm’s Law defines the relationship between voltage, resistance, wattage and electrical current. It tells us that if we lower the resistance of an atomizer coil – and the battery voltage remains the same – the circuit will draw a greater current and operate at a higher wattage. The wattage of a circuit is an expression of the amount of work the circuit does. In other words, a higher-wattage circuit generates more vapour. During the days in which the typical vaping device only operated at one voltage, lowering the atomizer resistance was an easy way to get an immediate increase in vapour production.

Lower Coil Resistance Means More Vapour

The sub-ohm vaping trend represents the culmination of the quest to get the biggest possible clouds out of a vaping device. An electrical wire is a bit like a water pipe. The wider a water pipe is, the more water can flow through it. The same is true of wires; a thicker wire has a lower electrical resistance. Therefore, using a thicker wire to create an atomizer coil results in a coil that has greater mass and surface area while operating at a higher wattage. That’s why sub-ohm vaping has become so popular; the more surface area a coil has, the more vapour it can generate.

Does Sub-Ohm Vaping Have Any Drawbacks?

As you’ve probably surmised from reading this article so far, the biggest draw of sub-ohm vaping is that sub-ohm coils can generate bigger vapour clouds than above-ohm coils. If you want a vaping setup that can generate room-filling clouds – and these days, that’s exactly what many vapers want – you need a sub-ohm setup. Those huge vapour clouds don’t come without costs, though, and you should be aware of those costs before you buy your first sub-ohm vaping device.

Sub-Ohm Coils Can Tax Batteries

As we mentioned above, decreasing the resistance of an atomizer coil increases the current drawn from the battery. Because sub-ohm vaping can tax batteries, it’s important that you purchase high-quality batteries and know what their maximum supported discharge rates are. It’s also important for you to know that sub-ohm vaping can drastically reduce battery life. It’s entirely possible that you could upgrade from a small above-ohm vaping device to a dual-battery sub-ohm vaping kit without experiencing an increase in battery life.

Sub-Ohm Coils Consume More E-Liquid

Moving from an above-ohm vaping device to a sub-ohm device will mean that you’ll enjoy much larger vapour clouds – but those clouds must come from somewhere. The more vapour your device generates, the more e-liquid it’ll consume. Some extremely heavy users of sub-ohm vaping devices consume up to 30 ml of e-liquid daily. Sub-ohm vaping is so popular – and it increases e-liquid consumption so greatly – that it has contributed to a general decline in e-liquid prices over the past few years.

What Is Sub-Ohm Vaping Like?

The first thing that you’ll do when switching from an above-ohm vaping device to a sub-ohm device is lower the nicotine strength of your e-liquid. With small vaping devices, it’s common for people to use e-liquids with nicotine strengths around 11-18 mg. When you switch to a device that generates triple the vapour volume, though, you’ll find a higher-strength e-liquid irritating and unpleasant to use. The most common nicotine strengths for sub-ohm devices are 3 and 6 mg.

Sub-Ohm Vaping Is Smoother and Puts Flavour First

Why would anyone switch to a more powerful vaping device while keeping their total nicotine absorption about the same? The reason is that lowering the nicotine strength of your e-liquid means that you’re getting a much smoother vaping experience with less throat hit. Although your body receives about the same amount of nicotine, you’re tasting the real flavour of your e-liquid without the nicotine getting in the way. After vaping for some time, many people decide that they no longer require the cigarette-like throat hit that helped them make the switch from smoking to vaping. They want something smoother and easier on the throat, and sub-ohm vaping delivers that experience.

Sub-Ohm Vaping Requires a Different Inhalation Style

The reduced nicotine strength isn’t the only thing about sub-ohm vaping that differs from above-ohm vaping. A sub-ohm tank can produce enormous vapour clouds. To produce those clouds, a sub-ohm tank will have large airflow vents and a wide mouthpiece. If you currently use an above-ohm vaping device – or you’re still a smoker – you’re probably used to drawing the smoke or vapour into your mouth before inhaling it. That’s not possible with most sub-ohm devices because of the very open airflow. With a sub-ohm device, you’ll inhale directly into your lungs.

What Is Above-Ohm Vaping Like?

If you happened to purchase a sub-ohm vaping device as your first e-cigarette, you might wonder what it would be like to “downgrade” to an above-ohm device – especially if you’re disappointed by the fact that the sub-ohm vaping experience is so different from smoking. As you’ve already surmised from reading the previous section of this article, switching to an above-ohm vaping device means that you’ll consume less e-liquid and that the e-liquid you use will have a higher nicotine strength.

Above-Ohm Vaping Feels More Like Smoking

The main benefit of above-ohm vaping is that it produces a more cigarette-like vaping experience compared to sub-ohm vaping. Since an above-ohm device usually has slightly restrictive airflow, you’ll inhale the vapour from your mouth to your lungs. Since you’ll also use an e-liquid with a higher nicotine strength, using an above-ohm device will feel much the same as smoking. When the vapour passes your throat, you’ll feel the same throat hit that you would with a cigarette. That’s why an above-ohm vaping device is usually the best choice as a first device for someone just making the switch from smoking to vaping. Did you begin vaping with a sub-ohm device? Are you less than completely satisfied with vaping because it feels too different from smoking? Try an above-ohm device; you’ll likely be much happier.