Minty Love - Single vs Dual Coil

Single vs Dual Coil

"One coil can often do the trick nicely, but how about duals?

Just one word - WOW!"

Rebuildable tanks are available with either a single or dual-coil build deck & most (but not all) dual coil RTAs are suitable for use with either one or two coils.

A single coil setup can be slightly simpler to set up with only one coil/wick, and possible the most efficient option for juice consumption overall, especially when the wick-resident juice is taken into account. Nevertheless, it's impossible to deny the advantages of a good dual coil setup, which can really take things to the next level. So assuming we have the choice - what factors might influence our decision?

Reasons For Choosing a Dual Coil Rather Than A Single Coil Setup

Increased Wattage/Potency Two coils provides a much greater safe max Wattage capability and (if used), far greater safe single-toke potency when compared to an otherwise identical single-coil setup. As explained in the tank buyer's glossary, many users find a single coil to be perfectly adequate in DTL "sub ohm" tanks. It's important to note that much greater Wattages and a higher toke rate will be needed to achieve the extra potency (see below)
Vapour Smoothness When properly using the additional Wattage/Potency of a dual coil setup, many will find the vapour to be unexpectedly & deceptively smooth. Although initially a pleasant surprise, such vapour can often pack an unforeseen & staggering punch, catching even experienced trippers off-guard. Therefore, caution is very strongly advised when using larger dual coil setups.

A fairly modest dual setup but still shows a much higher working Wattage range of dual vs single 26x2+36 5 turn 3mm. Note that a single coil of this type would smaller than ideal for myself, but a 6 turn version would be good

Wider Wire & Coil Choice For single coil setups, maximising coil heating surface area is often a top consideration, with choices often restricted by the build deck's terminal gap, & coil diameter limits. However, on a dual-coil deck, options can be far wider. For a dual coil DTL installation, I'd suggest starting with two coils with 5 or (if really looking for extra potency) 6 turns of 26x2+36, inner Ø 3mm. However, I've had excellent results from dual finer MTL claptons like 30x2+38. Feel free to experiment around, and suggest staying within the max wattage guidelines given by Wirebuddy - Note that wirebuddy gives max Wattage per coil so simply double up for two.
Wider working Wattage Range
Greater Juice Strength Versatility Dual coil operation opens up many more options for using weaker juice strengths, because a lot more potency can be achieved from weaker mixes than would otherwise be the case with a single coil setup.
My own usual de-facto starting mix for single coil DTL setups is approx 1:4 60PG/40VG (see Juice Buddy). This juice can also be brilliant in dual coil setups, although many find that weaker juices (e.g. a 1:5 or 1:6) can also work well depending on the coils/Wattage used. However, there's often so much Wattage headroom and excess of punch, the exact juice strength becomes less important.
Juice Consumption Unless the extra wattage/punch endowed by the dual coil setup is used, then it'll generally be more juice-efficient to use a single coil setup. Coils require a certain minimum Wattage to generate vapour at the optimum temperature/concentration for efficiency, so for most users it's generally preferable to have the Wattage dissipated by just one coil rather than split across two
Toke Rate As well as a higher Wattage setting, dual coils appear to require a stronger toke than single coil setups to obtain optimum performance. Insufficient toke rate when upgrading from single to a dual-coil setup is a common mistake, which inevitably brings disappointing and sometimes unpleasant results.