In the beginning, there was voltage mode, and it was good. Put a certain amount of battery voltage directly into a certain resistance, and e-liquid-soaked coils get hot, producing vapor: it was simple and easy, and we could do it in modified flashlight tubes. (Hence our word “mod” today!) Eventually, the desire to control both vapor output and flavor profile brought us to methods of controlling first voltage, and then wattage, to choose the amount of heat going into those coils. But as vapers got more sophisticated, and mod control chipsets became more widespread, we searched for a way to more directly control (or, more accurately, limit) the temperature of those coils, and thus temperature control (TC) was born.
What is Temperature Control?
So many people think that temperature control is just another gimmick, just another way to sell a new device, but nothing could be further from the truth. In reality, most of the equipment being sold today already has temperature control functionality, so generally, there’s nothing new to buy, unless you’re using the very smallest and simplest cig-a-likes and self-contained devices. While some devices are better at temp control, the functionality is out there and widely available and affordable.
The benefits of temperature control are simple but wide-ranging. The biggest benefit is of predictability, of consistency: by allowing the coils to only reach a specific temperature, every hit, from the first to the last, has the same heat, and the same flavor. No more guessing at wattages, no more adjusting for different coils: the device itself does all the hard work, so you only need to know what temperature you want to vape a given liquid at.
Because the other major benefit of temp control is flavor. When you can predict and control the level of heat, you can tune that flavor for the e-liquid you’re vaping, and get the same flavor every time. Or, alternately, you can actually change the flavor profile of an e-liquid by vaping it at a different temperature. Different flavor notes “wake up” at different temperatures. For instance, Reverb’s Dark Cabaret is a dark chocolate, blueberry, almond blend. At 450°F, the almond and the chocolate predominate, and at 500°F the blueberry comes out a little more. And all using the same coil!
TCR and TFR: A Tale of Two Methods
There are a couple of different ways to govern temperature control. Most of today’s devices use Temperature Coefficient of Resistance (TCR) to control temperature, as you see in the iStick Pico and iStick Pico Resin, and the amazing Geekvape Aegis mod. See, as wire heats up, its resistance changes, and the boards in these devices use that resistance to predict what the current temperature of the coil is. Different materials respond differently to heat, though, so each type of coil - stainless steel, nickel, titanium - will have a different resistance value for each type of wire, which the board comes pre-programmed with, and which the user must choose. Some boards even allow you to enter a custom TCR, so if you are using a coil material for which you have the coefficient, you can enter it yourself.
The other method is the one primarily used by Evolv and their DNA boards, such as those found in the SMY SDNA75 mod, and that’s Temperature Factors of Resistance (TFR). Whereas the TCR method assumes the response between resistance and temperature is linear, in reality, that response follows a curve. TFR is more accurate, because its mathematical model for the response of the coil to temperature more closely follows the real behavior of that material.
Both methods are wonderful ways of getting temperature control on your device; TFR is more accurate, absolutely, but TCR devices still give you that same consistent flavor and heat, every time.
Coil Architecture: Building the Perfect Beast
Depending on whether you’re using wattage mode or temperature-control mode, your coils will need to be built slightly differently. While tightly-spaced (or “contact”) coils in wattage mode produce maximum vapor production, this works best with materials like Kanthal, in which the temperature change doesn’t produce a great deal of resistance change - indeed, this is why Kanthal doesn’t make an appropriate material for temperature control!
But coils heat up from the center outward, so if your coils are touching, a temperature control mod will respond to the center resistance before the rest of the coil has heated up, depriving you of the vapor production of the outside of those coils. So while you can build coils that are tightly-spaced, you don’t want those coils to be in contact with each other.
This behavior of metal also means that the beautiful and vapor-intense Clapton and Alien Framed Staple coils you see on Instagram, and from our own Ninja Coils, won’t work with temperature control, but the wonderful thing about temp control is that it doesn’t need these intricacies to make consistent, predictable, wonderful flavor.
Materials Science...and You!
Every type of material has its own characteristics. The first TC boards were all TCR boards and, since the curve is fairly gentle, more linear, for nickel (Ni200) wire, they used Ni200. Many of the early adopters complained of a “flavor” to the Ni200, and it is an extremely soft material, so it wasn’t as easy to work with as the old stand-by, Kanthal.
When the next generation of TC boards arrived, with their changeable materials, many people went to titanium and stainless steel. Both of these materials are a little easier to work with. Titanium has the additional advantage of having a little steeper curve than stainless steel, so the temperature is usually more accurate. Stainless steel has the advantage of versatility: it can be used in wattage or TC modes.
At the end of the day, just like your choice in e-liquid, your choice of material is your own. Taste is subjective! The best way to decide which material is best for you is to study and experiment!
So What’s the Downside?
Temp control is powerful, but that power requires some knowledge and education. There’s a lot to learn, about resistance and temperature and coil-winding, but in its way, that’s no more different than learning Ohm’s Law for wattage builds: control requires knowledge. Once you’ve got it down, though, there’s no other method that produces the same quality, consistency and clarity of flavor, such a level of control over exactly what the flavor profile YOU want out of your vape. It takes a little research, sure, but it’s absolutely worth it!
Higher Education: How Can You Learn More?
Contact us! Mister-E-Liquid has a dedicated and knowledgeable support staff who are absolute wizzes at this stuff. You can call us during business hours at 855-647-8373, or email us any time at CustomerService@mister-e-liquid.com. Feel free to ask for Russ by name! He’s our resident temp control nerd, and on the rare occasion he doesn’t already know the answer to your question, he’s not only happy but excited to help you find the answer! He’s got the knowledge and the contacts to help you learn more about the wonderful world of temperature control.