Vaping 101: Sub-Ohm Vaping

Posted by Mitch Clarke on 10th Jul 2017


In the great big world of e-cigs, e-liquids, vapes and vapers, there's an equally diverse number of reasons why a vaper chose to pick up a vape for the first time, and why they continue to reach for it day after day.

Some people vape for the satisfaction, knowing they're staying far away from the alternatives.

Other ex-smokers make a hobby of it and find enjoyment in producing dense flavorful clouds! Who can deny that blowing big breezy billowing balls of cloudage isn't strangely reminiscent of a dragon, or maybe that hookah-smoking caterpillar in Lewis Carroll's famous folktale.

So, if you've found that vaping on basic devices are no longer doing the job, don't fret! There's so much more to learn about the nuanced and fascinating ways you can improve your vaping experience.

In this guide to sub-ohm vaping, you'll find all the information you'll need to not only decide whether sub-ohm vaping is for you, but also make a wise and informed decision on the gear you think you'll need to make your vaping experience perfectly perfect.

What is Sub-Ohm Vaping?

In the early days of vaping—back when cartomizers and clearomizers were omnipresent in the e-cig market, 18mg – 24mg nicotine levels were the norm, and achieving 50W with a regulated mod was unheard of—the resistances of the coil(s) in these carto/clearomizers were consistently above 1.0 ohm.

Sub-ohm vaping is the process of using an e-cigarette with any coil set that measures to a resistance lower than 1.0 ohm—meaning a .99Ω coil is technically a sub-ohm coil (just like a 0.08Ω coil), but a 1.01Ω coil is not.

Why Would I Ever Do That?

When sub-ohm vaping first emerged, it was out of necessity: mech mods had just been released to the market for first time. Lacking any circuitry to directly adjust voltage or wattage, early vapers discovered they could raise the wattage output of their mechanical device by lowering the resistance of the coil. Eventually, vapers became increasingly confident in their device and batteries, building coils with diminishing resistances to achieve wattage completely inconceivable at the time.

Non-mech vapers soon learned that while these sub-ohm resistance coils were best on mechs, they still gave fantastic performance on regulated mods, thanks to the increased size and unique styles of these sub-ohm coils.

While sub-ohm vaping is increasingly becoming the norm for the e-cigarette industry, it has its own set of unique pros and cons:


  • Big Clouds
    • High wattages mean high heat, which means big clouds coming out of your atomizer! If you're looking to chuck around some great balls of vapor, you'd do well choosing a sub-ohm atomizer.
  • Big Flavor
    • Higher wattages and big clouds also have the effect of producing rich, dense flavor.
  • Warm/Hot Vapor
    • While sub-ohm vaping requires a lowered nicotine level and equally diminished throat hit, getting a nice, hot vape has not only the effect of giving a pleasant kick to the back of the throat, but it assists in also bringing out the subtle and nuanced notes of your e-juice.


  • Maybe Too Much Cloud Coverage?
    • While big clouds are hardly something to be ashamed of, it's important to be considerate and mindful of those around you. Big clouds are great when you're outdoors or in your own home, but when in public or someone else's residence, it may be better to go with a vaping setup that provides the nicotine you crave without the massive cloudage that the uneducated public may find unsightly.
  • Juice Guzzler
    • The increased heat of a sub-ohm coil has the effect of producing bigger clouds, but these clouds have to come from somewhere! The bigger the clouds, the more quickly juice is being used. Great for purveyors of great tasting bulk juice (like this Jam Monster I'm vaping right now), but not so great for connoisseurs of expensive, rare juice.
  • Requires a Specific Inhale
    • Because sub-ohm coils are bigger and get hotter more quickly, they require increased airflow to keep them within a healthy temperature range. This is only achievable by inhaling deeply and directly into the lungs when drawing on your sub-ohm atomizer—this process is called direct-to-lung (DTL) inhales.
    • However, if you're more accustomed to pulling vapor into your mouth before inhaling (similarly to the technique that overcomes the tight draw of a cigarette), you may feel overwhelmed with the deep breaths of dense vapor you'll need to take in order to prevent your hot coil from scorching the wick irreparably.

Here's the Deets


Resistance (measured in ohms [Ω]) is an indication of how easily an electrical current can pass through a piece of resistive material. The lower the number, the easier the flow of electricity. This can be applied to almost anything—while metal has a very low resistance, something like the human body has an electrical resistance in the ~100,000Ω range.


Voltage (measured in volts [V]) is a measurement of the force pushing electricity through the circuit—the harder the voltage pushes against the resistance, the higher the wattage will be.


Just a fancy word for the relationship between voltage and resistance. As you lower or raise either, the wattage will adjust proportionally, whether directly or inversely. So when you adjust the wattage on your regulated mod, you're actually only directly affecting the voltage, which adjusts the wattage indirectly.


Amperage (measured in amps [A] and sometimes called current) is a measurement of how much/how easy it is for electricity to move through the circuit. The lower the resistance and/or the higher the voltage, the easier it is for more electricity to pass. Just don't let it get too easy, because if you do, your battery may not be able to handle the increased amperage—the suggested amperage limit is usually included with the battery itself, but these manufacturer-provided ratings can't always be trusted, so it's a good idea to double check with Google to make sure you're staying safe. Thankfully, we do our research on each and every battery that we sell, so you can rest easy knowing the amperage rating we provide for each battery is the most accurate available.

The Think Tank

I like to think of an atomizer & battery (or any closed electrical system) as a big water tank with a spout at the bottom. This spout is connected to a rubber hose that leads water back up and dumps it into the top of the tank.

As you add more water into the tank before opening the spout, the higher the water pressure pushing out water will be—this is a great representation for voltage, the force pushing electricity through the circuit.

As you widen or narrow the hose leading water back into the tank, it makes it easier or harder (respectively) for water to pass—the perfect analogy for resistance.

In a real hose/tank system, changing the width of the hose would also affect the water's exit velocity, but since electricity travels through metal at just under the speed of light regardless, "narrowing the hose" has no other effects.

How much water is coming out of the hose at any one time is a good portrayal of amperage. The more water coming out, the higher the amperage.

How difficult it is to bend the rubber hose after commencing the flow of water is a great representation of wattage. 

Similarly to a garden hose filling with water, wattage is not directly adjustable (you can't simply turn a knob with no other function than making the hose less or more firm), but by adjusting the water pressure or the hose width, you can decide just how sturdy the hose is. The wider the hose (low resistance) and/or the greater the water pressure (high voltage), the harder it will be to bend the hose (high wattage), and vice versa.

It's important to keep in mind that too much water coming out is very bad: if the water pressure is high enough and the pipe width is wide enough to make the tank overflow by even a single drop (not a perfectly logical analogy, but bear with me), this is when thermal runaway would occur in your battery.



An RBA (an abbreviation for 'ReBuildable Atomizer'; can refer to RDAs, RTAs, RDTAs, etc.) accepts user-constructed coils in the posts of the build deck. When they were first released, RBAs were used primarily with mechanical mods—because of this, sub-ohm vaping is practically an inherent quality of RBAs. While plus-ohm coils can technically be used in an RBA—especially older RTAs—with relatively good results, modern RBAs are designed for ≤0.5 ohm coil builds and have the generous airflow, wide drip tip, and advanced build deck to prove it!

Sub-Ohm Tank

Serving as the logical evolution of the lowly clearomizer, sub-ohm tanks use open airflow and large capacity tanks to fully utilize the ≤1.0 ohm coil heads they accept. These types of tanks will provide much bigger clouds of vapor and flavor that is more pure and rich, but can take some time to get used to if you're coming straight from a dated low-power clearomizer. Just make sure to prime your coil (by adding a few drops of juice directly to the coil head in order to fully saturate the cotton) in order to ensure that your first draw is a pleasant one!

Mech Mods

Mech mods are an incredibly unique vaping platform. Containing all of the advanced circuitry of a dollar store flashlight (so none at all), these devices use the direct output voltage of the inserted battery cell to power your attached atomizer. The only way to increase the wattage output of a mech mod is to adjust the resistance on the atomizer: by lowering the resistance, the wattage is increased, leading to sub-ohm vaping's early rise in popularity with mech users.

These vaping platforms are highly reliable, thanks to a lack of complex circuitry that can potentially fail, but this lack of regulators is exactly what makes a mech mod dangerous in the hands of those that don't respect the Ohm's Law. This is why we only recommend mechs to advanced vapers who have done their research. 

As such, before installing your atomizer, always ensure that your device is assembled completely and correctly. In addition, your ohmmeter is your bestie, use it to check your atomizer's resistance often!

And if you happen to be using a mech mod with a hybrid 510 connection, I'm sure you've heard this a million times over, but...for the love of goodness gracious, always make sure that your atomizer's positive pin (the metal piece in the center of the 510 threads) is protruding past the threads. 

This is by far the most common reason for a mechanical mod to fail catastrophically, so it's crucial that you protect your goodies. If you can't tell or you don't know if you can use it, simply don't!


While it's important to note that while a mech mod requires a change in resistance in order to achieve a change in power output, a regulated mod doesn't necessarily have the same requirements. It's true that some mods can only achieve the upper portion of its wattage range with a sub-ohm atomizer, but for the most part, a lowered resistance won't have much of an effect on your vape performance. 

Simply raising the wattage will have the same effect, no matter the resistance. If you're seeking big clouds and rich flavor from your regulated mod/RBA, it's best to build a large coil with a higher resistance (~0.5Ω) and plenty of surface area for juice to contact before being vaporized.

Temperature Control Mode

It's worth mentioning temperature control–compatible coils: these types of coils (typically made from either nickel, titanium, and stainless steel) are very likely to be sub-ohm due to the comparably low resistance of these three materials, but only stainless steel can be used outside of TC mode (something most regulated mods incorporate, but remains impossible for mech mods to achieve).

Juice Type

It's important to note that while you can technically use whatever blend of juice you'd like, high VG (50%+ VG) blends typically work best, if only because the harshness of high-PG juices is only amplified by the increased heat and vapor production of sub-ohm coils, while high-VG juices remain smooth and silky.

It's also crucial to stay mindful of the nicotine content of your juice of choice. Because the vapor production of sub-ohm builds is so great, it multiplies the amount of nicotine you're intaking. So if you're used to an 18mg juice in your iCare, it's probably a good idea to switch to a 3mg or 6mg juice in your sub-ohm tank or RBA.

Battery Safety

And lastly, but by far the most important, it's crucial to stay safe while sub-ohming, especially with mech mods. Incorporating advanced safety features into a regulated mod (short circuit protection, resistance limits, etc.) has become the norm—and for good reason! 

However, because mechanical mods, by definition, lack any sort of regulating circuitry, it's overwhelmingly important for mech users to do a consistent and periodical check-up on each and every build installed. This means double-checking the resistance on two different ohmmeters as a best practice before installing on the mech as well as immediately after putting on the top cap. 

You should also use an Ohm's Law calculator to find your present amperage draw and compare that against the amp rating you find online. These safety steps should be completed before you even think about putting your lips on your mech—better safe than sorry!


And there you have it: just about all you need to know about sub-ohm vaping, all in one easy-to-access place. Feel free to keep this page close at hand and reference it whenever the need arises. And if you feel like I've glossed over an important point about sub-ohm vaping, or you just feel appreciative, let me know below!