Updated August 2019 by Lee Johnson
I still remember the time a customer wound up one of our customer services team by requesting a dual-triple horizontal-vertical kryptonite coil.
Perhaps because of the amount of coils and tanks coming in at the time, she passed on the request to our product manager – to much merriment.
And if anything, there have been even more coils and tanks coming out since then!
- Essential glossary
- Design type
- Choosing a Coil Design/Style
- Wicking and Juice Holes
- Building Your Own Coils
If you aren’t already familiar with coils, you’ll find the following definitions helpful when reading this article!
BDC: Bottom dual coil
BVC: Bottom vertical coil
Cloud chasers: Vapers who like to create large clouds of vapour.
Mesh: Steel wire mesh, has great wicking ability or a type of coil with a mesh-like appearance.
Ohms: Unit of resistance
RDA: Rebuildable dripping atomisers
Resistance: A measure (in ohms) of how much an obstruction (the coiling wire) resists the flow of energy
Silica: High temperature resistant glass fibre, doesn’t burn like cotton does when dry
Wicking: The placement of material within, or around, a coil to keep liquid in contact with it
For more vaping terms see:
Each of the following materials is commonly used in coils.
Used in wattage mode.
- Can handle very high temperatures
- Easy to work with
- Readily available in many gauges to suit different build needs
- Very stable resistance
- Usable with every device
- No temp mode functionality
- Can cause a drop in flavour clarity after prolonged use, but generally pretty good.
- Can taste metallic when first installed
NiChrome (80% Nickel / 20 % Chromium)
Used in wattage mode
- Resistant to high temperatures
- Heats quickly (low ramp-up time)
- Easy to work with
- Holds its shape well
- Contains nickel (an allergen)
- Not as easy to find these days, it was more common in early vaping devices
- Heat resistance isn’t as good as kanthal (but still more than good enough for vaping purposes)
Ni200 (nickel, 99.6%)
Temperature control (or as I prefer, temperature limiting).
- The standard wire for temp control mods
- Resistance changes during heating are accurately predictable (this is how temp control coils work: they change resistance as they heat, the device picks up on this, and knows what temp they are at due to the change)
- Due to the the accuracy of the readings it gives a very consistent vape, in both performance and flavour
- At high temperatures, e-liquids base chemical elements can transform, leading to undesired formulas. This can help prevent that happening
- When building, tricky to work with due to the flexibility of the wire
- If not built with just the right amount of wicking, can lose consistency
- Only usable in temp mode, NOT to be used in wattage
- Some people are allergic to nickel
- More prone to gunk build up
Temperature control mode only
- Stronger than Ni200, making it easier to work with
- Higher resistance than Ni200 (nearly double), so fewer wraps are needed to achieve a suitable resistance
- Clean, crisp flavour
- Solid performance in temperature control mode due to consistent resistance changes with increasing temperature.
- Generally harder to find than Ni200
- Can’t be used in wattage mode
- More expensive than other wire materials
- Some concerns have been voiced over toxicity – but this isn’t an issue if you only use it in TC mode, because it has to reach 1,200 °F / 649 °C, which isn’t possible in TC mode.
Wattage and temp control
- Very versatile working for both Wattage and TC Modes
- Easier to work with than Ni200 for temp coils, as it holds shape better
- Can last longer than a kanthal coil
- Heats very quickly, delivering a more instant hit
- Shorter ‘breaking in’ period than kanthal, less metallic taste
- Subjective perhaps, and may be different depending on liquid used, but many people say it has a cleaner, purer taste than kanthal
- Resistance fluctuates with heat, so less consistent in wattage/power mode
- More likely to suffer from ‘hot spots’ when building a micro coil (where each loop touches, hot spots arc the current across wraps rather than flowing through each one)
- Better performance when you can control wattage within a temp setting, than when wattage/ramp up is non changeable
Having gained more popularity since the release of the original sub-tank, the Aspire Atlantis, the vertical coil has now become far and away the norm in stock coils.
In a vertical coil device such as the Aspire Cleito the coil stands upright, surrounded by a cotton wick. This allows for a direct airflow, because there is a straight path up through the centre of the coil that leads to the mouthpiece.
Couple this with a large core diameter, which allows more air to pass through the coil more quickly – producing more vapour – and you start to see why they have become so popular!
An additional benefit in terms of vapour production and flavour is that they tend to be wicked from the outside, which increases the surface area of the coil making contact with the wick. All else being equal, this will vaporize more e-liquid and improve the flavour and vapour, relative to a coil with the wick through the inside.
This direct airflow allows the coil to have a consistent heat along its length, giving a more even evaporation of the e liquid. This in turn gives you a more consistent vape and flavour, and also reduces the risk of dry spots which can burn the wick.
- Vertical coils evaporate e-liquid more evenly
- Allow for greater airflow
- Excellent vapour production
- (Arguably) better flavour than horizontal coils
- More consistent performance
- (Arguably) less chance of spitting
- Great for pre-made tank coils
- Harder to build yourself
- Limited benefits in RDAs
- Not everyone agrees about improvements in flavour
Design: Horizontal Coil
Due to the increased popularity of vertical coils, the horizontal design has become much less prevalent in recent years.
Vertical coils can have either inner or outer wicking. However, you won’t find a horizontal stock coil with outer wicking, and it’s rare for DIY coil builders to use these too.
Due to the way that airflow passes up around these coils, if they’re not centred properly, there may be some performance variation between like for like coils. However, this is unlikely to be as noticeable when compared with DIY coils in an RDA placed incorrectly.
- Performance is still good enough for most vapers
- Much easier to build on RDAs
- Wicks evenly from both sides
- Some people prefer the flavour
- Less commonly found as pre-made coils
- Less airflow
- Wicking around the outside doesn’t work as well
- Performance can vary more
Spitback in Horizontal and Vertical Coils
Another contentious matter is spit back, when the coil occasionally spits hot liquid into your mouth.
Logic would say, due to the direct airflow, vertical coils would be the worst culprit. However, horizontal coils can also sometimes spitback as evaporation takes place on the outer edge of horizontal coils, and some vapers claim less spitback with vertical coils. One argument is that the bits of e-liquid “spat” out by the coil largely go upwards with horizontal coils, while they would be spat out to the side with vertical coil designs, and there is a possibility that the wick would block them from making their way up to the mouthpiece. However, there is much debate on this point.
My personal tip for limiting this with any tank (opposite to some tips also found here!), is to fire it for a second or two before placing it to your lips. That’s because spitting generally occurs immediately after firing.
You can also adjust the power up or down, as different atomisers tend to spit more at varying voltages. Of course this isn’t always ideal, especially for cloud chasers! If their particular model spits more at higher power, they don’t want to turn it down!
Mesh and Plexus Coils
Firstly, mesh coils are generally not actually made of mesh. They are usually made of thin pressed metal, with holes punched through, giving a vague appearance of mesh and frankly that of a cheese grater. I personally would call them something like a punched heating element, or an aerated heating element. Mesh itself was originally primarily used as a wicking material, which we shall cover later on in the article.
In most mesh coils, the material (kanthal or stainless steel dependant on atomiser) is set in a C shape around the inner of the wick, each side linking to the base of the atomiser to make the positive and negative connections. It covers the vast majority of the surface area of the wick, offering decent vapour production, which in turn produces an improved flavour, although of course taste is subjective.
As the element has quite a lot of metal, you would think that ramp up time (the time it takes to heat to performing temperature) would be slow, but this isn’t really noticeable with these elements. They’re generally thin and so the ramp-up time is actually quite short.
- Great vapour production
- Solid flavour
- Fast ramp-up and cool down time
- Long-lasting coils – the mesh evenly spreads heat and lasts longer than most other coil designs
- Available for increasing numbers of tanks, and some RDAs now have clamp-like connections designed to work with mesh too
- A more consistent vape than most other coil types
- Quick wicking reduces the chance of dry hits
- The high vapour production means a higher juice consumption
- Still less common than more basic coil types
Multiple Coil Atomisers
Smok were the manufacturer to pioneer this corner of the market, with their Beast series of tanks and atomisers. The theory with a multiple coil head is the same as the mesh style atomiser; they aim to maximise the surface area contact between wick and coil, which in turn maximises the potential vapour and flavour production.
In short, a multiple coil atomizer is very similar to a single coil atomizer (usually using a vertical design), except with more than one coil either housed in the same section or with multiple sections in the atomizer head each containing one coil. This is usually done in “parallel,” meaning that the current splits across each coil, effectively reducing the overall resistance and still sending plenty of power to each coil.
- Excellent vapour production
- Good flavour
- Widely-available in pre-made coils
- Generally low resistance despite the high surface area of the coils
- Most RDAs are set up for building them
- Higher ramp-up time
- Generally work better at higher powers
- Wicking isn’t perfect, so dry hits are possible if you chain vape
- Use more juice than simpler designs
- They only work as well as the worst coil – more coils means more chance of purchasing a bad one!
Another technique used to maximise surface area is the parallel coil. Essentially it’s two or more separate lengths of wire wound together into a coil, so rather than having multiple individual coils, you have the same amount of material in a single coil.
In principle, parallel coils offer many advantages over basic multi-coil atomizers, especially because the airflow through the centre of the coil can be maximized and it makes wicking much simpler compared to multiple coils.
- Generally match dual coil designs for vapour and flavour
- More consistent wicking due to the coil layout
- Widely-available in pre-made coils – many “dual coil” designs are actually parallel coils
- Supported by the vast majority of RDAs
- Good airflow
- Higher ramp-up than simpler designs
- Higher juice consumption
- Work better at higher powers
- RDAs with smaller post-holes may not fit them
The Clapton coil is named after the guitarist Eric Clapton, because from the outside they look like guitar strings. The concept is simple, and yet another example of vapers trying to maximise coil surface area to boost performance: a thicker, central “core” of kanthal has a thinner strand of wire tightly wound around it, and this guitar string-like wire is used to wrap the coil.
The thicker central wire keeps the resistance low (because it allows a low-resistance path for current to flow through) but the thinner winding drastically increases surface area and thereby improves vapour production and flavour.
- Increased vapour production compared to standard coils
- Great flavour
- Quite easy to find – you can even buy pre-made Clapton wire for building your own coils
- Usually wrapped into a standard single coil shape, so wicking is easy and works well
- Long ramp up times because they use more wire
- Needs high wattage settings to work well
- Uses a lot of juice
- Spitting and popping seems more common (based on personal experience)
A ceramic coil is actually a bit of a misnomer, because ceramic coils are really ordinary coils encased in a ceramic wick. This can be done either by coating the coil material in ceramic and wicking it with cotton like any other coil, or by encasing the whole coil in a cylinder of porous ceramic – these can be wrapped with cotton on the outside but this isn’t necessary or especially common.
The theory behind ceramic coils is more about the longevity of the coil than performance. Because ceramic is heat resistant, the idea is that there is no risk of burning the wick, which means the flavour and performance should remain consistent for longer than with an ordinary coil.
- Coils last much longer
- Flavour and vapour production as good as standard coils
- Much less likely to get a dry puff
- Spitback is drastically reduced – the coil is surrounded by ceramic, so any spitting won’t make it up to the mouthpiece
- Not widely available and no way to make one yourself
- Some credible safety concerns from ceramic particles in the vapour – this is a complex issue but you can read more here and here.
Apire Revvo Coils
Another thing worthy of mention is the Revvo ARC or Aspire Radial Coil. Again we have the metal with punched holes thing going on, originally sported by the Notch Coil from Wismec, but this time it’s the flat design with wicking below that’s rather different. It looks a little like a stovetop on an electronic oven, a flat circle with a hole in the centre and arched slots cut into the metal around it.
Having the full surface of the wick open to the tank below, this has to be one of the best wicking atomisers on the market, as long as you tilt it often enough to ensure that the liquid makes contact with the wick itself.
One negative of this design, if left on its side the liquid eventually floods the wick and passes through, allowing the liquid to run out of the upper section of the tank. In essence, stored upright and tilted during use (both of which most vapers tend to do without any forethought), and you have an excellent performing tank.
- Great wicking
- Long-lasting coils
- Good flavour and vapour
- No spitback
- Not widely used at all
- Flavour and vapour better from other designs
- Flooding issues if the tank is left on its side
Other Coil Types: Alien Coils, Twisted Coils, Fused Claptons, Tiger Coils and More
The customer service agent from the introduction searching in vain for a “dual-triple horizontal-vertical kryptonite coil” isn’t as silly as it might seem when you learn about the staggering and frankly baffling variety of coils that vapers build for themselves.
From twisted coils – two strands twisted together before making a coil – to fused Claptons – basically a Clapton but with multiple cores “fused” together – and tiger coils – a twisted coil but with one of the strands being ribbon kanthal – it’s hard to keep on top of every option out there. But the key factor with most of these coil designs is that they tend to focus on increasing surface area through increasingly-complex designs.
Of course, the variety of coil types covered in this section makes it difficult to give a distinct set of pros and cons to each one, but broadly speaking they do share some benefits and downsides:
- Generally excellent vapour production and flavour
- Some designs reduce ramp-up time while still offering greater surface area
- Usually low in resistance
- Usually challenging to build
- Not widely available
- Tend to need higher power settings to work well
- Only fit in RDAs with large post holes
There is more information about specific coil designs mentioned in this section in this Vaping360 post.
Choosing a Coil Design/Style
This section I have found difficult to write, as there are so many variables between different atomisers and tanks.
This includes airflow, chimney diameter, the placement of the coil in comparison to the chimney, and so on.
Whereas a variable power mod is much the same as the next (quality and power aside, and for simplicity’s sake in this article…). You turn it up, you turn it down, and that’s about it.
In a nutshell, all coil styles can produce both really good flavour and vapour production, dependant on the above factors, and the subjective views of the user. My only advice here is to try as many as you can, and see which you prefer.
The best advice when it comes to choosing the type of coil that’s right for you is to think about what’s most important to you. Do you want huge clouds? Go for Clapton coils or one of the many more exotic builds around, or at very least mesh/Plexus, parallel or dual coils. Do you care more about longevity? Then mesh/Plexus, Revvo and ceramic have definite advantages over the competition. Do you want something you can get great performance out of without needing huge wattages or having to deal with long ramp-up times? A basic vertical coil is probably ideal.
Again, the best thing to do is consider the benefits of each and what matters to you, but crucially to try as many as you can and then make your decision based on your experience. Finding the perfect vape for you is always more of a journey than a nail you’ll hit on the head on your first swing.
Wicking and Juice Holes
Wicking material can differ between cotton (organic, and unbleached), silica and mesh, but in stock coils the most widely used is cotton.
Cotton is a very good all rounder in regards to:
- vapour production
- the amount of liquid it can hold
- ease of use
Silica is used in more ‘old fashioned’ tanks (such as our H2 model) and previous CE incarnations, and is sometimes used by vaping enthusiasts as a preference.
Mesh (actual mesh, not like the modern coil material) is almost exclusively used in ‘Genesis’ tanks (so called after the original bottom tank/top coil design), and occasionally in RDAs.
If building coils yourself, it is important to get the amount of wick just right.
The general rule of thumb with wick passed through the coil, is to have a slight pull as you adjust the cotton back and forth, but no substantial resistance. The wick should make good contact with the coil when it’s dry but not be packed so tightly there is no room for movement.
This leaves room for it to be soaked with liquid (expanding as it does so), without becoming so tight that the liquid cannot flow at a decent rate.
As a general rule, the higher the resistance, the less wattage you need for your tank to perform.
The lower resistance the more power you need, and the more vapour it will produce, though there are exceptions.
Higher resistance coils, generally in the 1-2 ohm region, are primarily used for mouth to lung style vaping. These are best run (again this is a general rule, devices and coils vary in performance) within the 7-20 W range.
These types of coils tend to heat slightly slower, are better suited to higher nicotine levels than sub ohm coils, and are best for those seeking more of a smoking like experience.
Sub ohm coils, those below 1 ohm of resistance, are more suited to those who prefer a full on vape, an instant rush of masses of vapour.
The lower the resistance, the faster it vapourises liquid, due to a combination of surface area and the speed at which it heats, and the more powerful and safe a battery you will need.
Please note that there are risks when you start coil building and modding. We take no responsibility for any issues that arise should you start coil building.
This section should be taken purely as an introduction, and there are links to more detailed guides for those interested.
Coil Building Safety
Before embarking upon building your own coils there is one major thing to remember!
Check the resistance of any coil before firing it, using either a dedicated ohm meter, or a regulated device that will show your resistance.
There are two reasons for doing this.
- Ensuring that the resistance is within your devices limits.
- Ensuring that the coil doesn’t short, which can lead to serious battery failure and injury.
I once killed an £80 device by forgetting this golden rule, and I wasn’t even building a fresh coil, but simply re-wicking an old one.
If it wasn’t for the fact my batteries were easily and quickly removable, it could have been much worse!
Building your coils
When building your own coils, it is important to consider exactly what type of vape you desire, and to tailor your build to suit.
Using a coil building app or website (such as the one at Steam Engine) can help greatly in choosing the correct wire and gauge.
The space you have to work with, and the number of coils you are able/wish to use, can help determine what wire is best.
If you prefer a 0.5 Ohm build and have both a restricted decked single coil device, and a dual coil larger deck, then a different type of build is required for each. A dual coil build halves the resistance. So to achieve the same result, you would need to double the resistance in each individual coil of the pair.
A smaller single coil using kanthal wire @0.5 Ohms would need 6/5 wraps of 26awg (AWG = American Wire Gauge) kanthal. Using the same gauge wire you would need double the wraps for a dual coil, making the coils possibly too wide.
A larger dual coil using kanthal wire @0.5 Ohms would perhaps have 9/8 wraps of the higher resistance 28awg. The larger area should then produce more vapour, yet the larger mass of metal may slow ramp up time. In this example, it shouldn’t make a very noticeable difference.
As a rule of thumb, spaced coils (where the loops do not touch) are better for temp control vaping, due to there being no risk of hot spots, and micro coils (where each wrap sits flush to the next) is preferred in wattage mode.
As mentioned, this was an introduction to coil building. If you are interested in going further, here are a few resources to get you started!
Getting Started Building Your First Coil: God of Steam posted a good guide to building a spaced coil (the style used in temp mode).
Kayfun 3.1 Microcoil and Cotton Guide: ECF member Romelee posted this guide to building on a Kayfun, a rebuildable tank that has a similar deck to many, with this guide being more for coils used in wattage mode.
Subtank Mini Nickel Build: Finally, check out a great video showing how to rebuild the Subtank Mini for temp control, posted by Vaping Pauly.