How Does Temp Control work?

Authored by Jessie Cyr-

So, just about every regulated mod on the market now has a number of “Temp control” functions, but what exactly is that? Temp control is the mod adjusting power to the coil so that it meets, but doesn’t exceed a given set temperature. Temp control requires specific types of wire; stainless steel, nickel, or titanium wire are the most common, though some mods also have “TCR” or “TFR” modes or options for additional wire types like tungsten or on YiHi chipsets the “SX-Pure” mode. Kanthal wire, which is the most common type of wire used in pre-built coil heads unfortunately is incompatible with temperature control. It is worth noting that many temperature control wire types are not recommended for use with the more familiar wattage mode, as they can give off toxic fumes above typical TC temperatures.

So how does the mod do this? Well, when the mod provides power to the coil it heats up, and for many wire types this will create a change in the coil’s resistance. How much it changes is different from metal to metal, which is why the mods have so many different modes/options. To accomplish an accurate temperature control experience the mod often requires that the user “lock in” a cold resistance reading. Since the change is a known percentage of the original or cold resistance, the mod will read the resistance several times per second to make sure that the temperature has not been exceeded.

When this is done right, the mod will reduce the amount of power (often displayed as “watts” on the mod screen) as the resistance change indicates the desired temperature is close to being reached. Once the coils have reached the user defined maximum temperature, the device should be limiting how much power is sent to the coils to maintain the temperature without exceeding it. In doing so the mod will do two things: Prevent dry hits, and keep the temperature at a level that can be easily inhaled by the user. This can, with accurate temp control, make for an extremely satisfying experience.

On that note, perhaps we should address different wire types. There are several different wire types that are suitable for vaping. We have FeCrAl (Iron, Chromium, and Aluminum) alloy wire, commonly known by the branded name Kanthal. This wire is very easy to work with, durable, has a reasonable resistance for building coils, and is fairly inexpensive. This has been the standard wire type in coil building for quite a while. It is very reasonable to assume that if a premade coil doesn’t specify the type of wire used, that it is kanthal. We have Ni80 or “Nichrome” wire, which is a Nickel and Chromium alloy.

This is also not suitable for temp control but has a lower resistance than kanthal, and heats up quickly. It is an excellent wire for mechanical mods and for regulated mods where users want to minimize ramp up time. We do also have three common wires that work very well in temp control, Ni200  which is classified as “commercially pure” nickel wire. Ni200 is one of two older temp control wires, and is known to work reliably in temp control, but is fairly difficult to work with and is notably dangerous in wattage mode as it will give off toxic fumes at higher temperatures. Titanium (Ti) wire is as well a reliable temp control wire with a higher inherent resistance than Ni200 and is generally easier to work with as well. It is worth noting that titanium can also give off toxic gasses and has the potential to ignite if heated in wattage mode.

Currently the most popular wire for temp control use is Stainless steel, specifically 316L grade steel, which is composed of nickel, chromium, and molybdenum among other incidental components. 316L steel is medical grade and frequently used in food preparation applications, it is safe to use in both wattage and in temperature control applications. If your mod and atomizer support 316L temp control I, for one, would highly recommend it be used over TC specific wires. As I mentioned, there are many other wire types that will work in temp control on various mods but none of which are as broadly available or compatible with as many devices as the three discussed here.

At the end of the day, many vapers are perfectly content to use their devices in standard wattage mode, and there’s nothing wrong with that! However, if you are curious about the benefits of working with temp control wire, many atomizers have premade coils made of one or more of these metals, and if you’re building your own coils, there is very little harm or cost associated with buying some stainless steel wire to give it a shot.