Vape coils are the replaceable element in vape kits and tanks. It is the coil that takes the power from your vape battery and turns it into heat, which is then used to turn e-liquid into vapour. Inside a standard coil model, you will find a length of coiled wire wrapped around an absorbent wick.
The wire creates heat, while the wick absorbs the e-liquid held in your vape tank. The two elements of the coil work in combination, with the wick supplying a steady source of e-liquid for the wire to heat into vapour.
You will find coils in any atomiser (the umbrella term for tanks, pods, and rebuildable atomisers) and they come in a variety of resistances, builds and materials which offer vapers a particular style of vaping.
Manufacturers will create specific coils for their atomisers and if you have purchased an atomiser or kit it will often include compatible coils, always check carefully when buying replacements to make sure they will work with your kit.
A coil’s resistance is measured in Ohms. Ohm’s Law describes the relationship between current, power and resistance, and is very useful to understand as it directly relates to vapour production, which can help you decide which coil is right for you.
A common analogy for understanding Ohm’s Law is to imagine the plumbing in your home. The Voltage of your battery is the water pressure, the Amp of your battery is the water flow and the Ohm resistance is the width of the pipe.
So coils with a lower resistance will require a higher power output, and a higher Amp output, just like a wider pipe will need a higher water pressure and increased flow of water to work properly. Conversely, a higher resistance coil requires a lower power output and a lower Amp output.
While all coils are designed to vapourise e-liquid, they can perform differently - this is on purpose. By using different types of wire and wick, you can effectively change how much vapour can be produced as well as enhance flavour and the lifespan of the coils. Coils are broadly split into two categories: sub ohm and mouth to lung.
MTL (Mouth To Lung) coils get their name from the style of vaping they support. Mouth to lung vaping describes the process of inhaling vapour into your mouth and then carrying it into your lungs, the same way you would smoke a cigarette. This style is especially popular amongst new vapers as it feels very familiar. In order to accommodate this style, mouth to lung coils have a high resistance (1.0 Ohm or higher) and will produce a small amount of vapour.
Not just for beginners, mouth to lung coils also have the effect of intensifying the flavours of e-liquids, so they’re a big hit amongst vapers looking to experience a better-tasting vape. As an added bonus, these coils produce less vapour, so they will also consume less e-liquid and ultimately last longer, making them ideal for vaping on a budget.
Sub ohm coils, on the other hand, have been designed for creating large amounts of vapour. They get their name from their resistance, a sub ohm coil will always have a resistance less than 1.0 Ohm. This low resistance means they’ll accept a greater level of power and heat more e-liquid at a faster rate, this is why they produce larger amounts of vapour. They are also called DTL (Direct To Lung) coils because they allow you to adopt a direct to lung vaping style, wherein you inhale vapour straight into your lungs without holding it in your mouth first.
In order to use a sub ohm coil, you will need to have a vape kit or device that can produce larger amounts of power. These will normally be more expensive than a standard mouth to lung kit and have been designed for advanced vapers.
Requiring more set-up and knowledge about vaping is one of the reasons that they are not recommended for new vapers. The other reason is that large vapour production takes some getting used to and is not necessarily something you’ll want to experience as a first time vaper.
Rebuildable coils have been created for the purpose of being used with rebuildable atomisers. They require a far greater knowledge to use safely, including knowledge of Ohm’s Law, battery safety and general vape knowledge. Rebuildable coils are the pinnacle of customisability, as they allow you to pick an exact resistance and use metals of your choosing, including exotic metals such as Titanium and Nickel.
Rebuildable coils are mounted onto the build deck of a rebuildable atomiser and have hand-made cotton wicks threaded through them to soak up the e-liquid that is dripped directly onto them. The result is a coil and atomiser that delivers a greater amount of cloud and flavour than even a sub ohm tank coil is capable of.
As aforementioned, Ohm’s Law explains the relationship between power and coil resistance. Using your coil at too high a level will run the risk of burnout, whereas too low a level can cause e-liquid build-up and a lack of adequate vapour production. Finding the sweet spot behind the two isn’t as difficult as you may think.
Modern coils will most often have an advised power level printed on them, usually recorded in Watts (W), for example, 40 - 55W. If you stay between this range you’ll have a far better vaping experience.
It may be the case that you don’t exactly know which power to use. If this is the case we recommend that if possible you set your vape device to the lowest wattage and slowly increase power by 10W after each puff, until you find the power level that best suits you.
This won’t be a problem if you’re using a vape kit with a fixed wattage output, as it will be preset to deliver a power output to match the coils that are included with the kit which essentially takes away all of the messing around.
E-liquid and coils work together to produce vapour, so making sure you’ve found the correct e-liquid for your coil is very important. This largely comes down to two factors; thickness and nicotine strength.
The two main ingredients of e-liquid are VG (Vegetable Glycerin) and Propylene Glycol (PG), which are both widely found in food and medicine. The levels of VG and PG will always add up to 100%, for example, 70% VG / 30% PG or 50% VG / 50% PG. E-liquids with a higher PG percentage will be thinner, and will require less power to be heated into vapour. Whereas, e-liquids with a high VG percentage will be thicker, and consequently require more power in order to be vapourised.
PG basically bonds flavouring and nicotine to the e-liquid, therefore the more PG usually translated to increased flavour. VG, on the other hand, relates to how much cloud is produced, with higher VG consistencies producing larger amounts of vapour.
If you plan to use a sub ohm coil we recommend an e-liquid that is 60% VG or higher. If you plan on using a mouth to lung coil, then an e-liquid that is 50% PG or higher will work best.
While preferred nicotine strength is often a personal choice, it’s important to remember that sub ohm coils will heat more e-liquid to produce more vapour. What this means is that you’ll also experience a greater nicotine hit.
Our advice is that if you use sub ohm coils, you should use an e-liquid that’s no stronger than 6mg. MTL coils meanwhile, are compatible with all nicotine strengths, so you have the choice of a low strength or a high strength whatever your preference is.
Setting up your coil correctly the first time will guarantee a better experience. Some kits will come with a coil already fitted, if this is the case it’s recommended to take the time to check that the coil is securely fitted inside the tank.
If your coil arrives loose, check it’s in good condition. On your coil you may see small rubber rings, called O-rings, they act as a seal to ensure your tank doesn’t leak when it’s filled with e-liquid. Before installing your coil check that the O-rings are intact. These O-rings will also be found in your tank, again, check their condition before installation and use.
Insert the coil into the base of the tank and tighten it by hand, not too tight otherwise you won't be able to unscrew it, never use tools unless specified in the manual.
Once your coil is installed, it’s time to fill your tank with e-liquid. Once filled you should leave your device upright for 5-10 minutes, allowing e-liquid to properly soak and saturate into your coil. If you skip this step you run the risk of burning out your coil, making it unusable before you’ve even started.
Coils will eventually need to be changed no matter how careful you’ve been. As a general rule, most manufacturers recommend changing the coil after a week of use. If you solely use a vape device this will be seven days, however if you don’t vape that often, you may find that changing your coils every two weeks is sufficient enough.
To detect when you need to change your coil, follow this list for our key things to look out for:
The quickest way to tell if your coil needs changing is by taste, if you notice a taste like burnt metal or fibre then we recommend replacing it straight away.
If the cotton in the coil has taken on a dark brown or black colour it means that it has begun to deteriorate. While it might not taste different for now, we recommend changing it nonetheless.
The smell of burnt metal or fibre coming from your tank will mean that you are either vaping at too high a wattage or need to change the coil altogether. Reduce the wattage immediately and then check to see if the smell persists. If it does then replace your coil.
Due care and attention of your coils can go a long way, saving you time and money in the process. What’s more, is that maintenance isn’t usually an arduous task and only requires some basic upkeep to see clear results.
To combat this, try dropping the VG levels of your e-liquid choice by 10% and make a move to a simple, one-note flavour blend. The results can be instant.
Coils are vital piece of vape hardware which can be daunting on first experience, but they are easy to pick and use when you know how. We hope this guide has helped give you some more confidence in relation to all things vape coil.