Hi All
Thought it would be good to have a dedicated thread for temp control Q & A for newbies (and veterans alike to help us noobs)
I've recently got into building my own coils one of the things I've noticed is how easy it is to get a dry or burnt hit especially when you put in some of those bigger coil builds. Now I know some will say that's a wicking issue or try turning down the wattage.... whilst that is true, in a lot of cases these chunky heaps of coiled madness just can't cool down quick enough!
so I started looking into temp control as a means to maintain the flavour...draw for long periods of time...chain vape like a madman...avoid cremating my cotton...and not mash up my coil that I spent bloody ages building!
What I've learnt so far
There are 4 main things to remember for temp control
1) All metals change resistance when heated, but it's those metals that change more that are the best suited for temp control, and its for this reason most temp control mods have Nickel, Titanium, and Stainless Steel as a default ...imagine a hose pipe fully open, now pinch it (resistence in our case), it's harder for the water (current in our case) to get through... that's exactly what's going on here as the metal is heated.
You will start with a new coil build at say 0.3ohm at room temperature and when heated it goes up to 0.5ohm ...the resistance goes up (some metals change far more than others) this effect is known as Temperature Coefficient of Resistance (TCR*) It's the average amount the resistance changes for every 1 degree Celsius heated
(*note there is a proper temperature curve some devices can utilise which is different to the average linear line that is TCR but for ease of explaination I'll stick to TCR)
note 2, Kanthal is usually out of the question for temp control on most mods as its resistance changes so little when heated
Edit: Hohm wrecker G2 claims to support this metal type thanks
@PhantomOp
2) The type of Metal you choose for your coil changes the correct TCR you use on your mod (I believe I've read somewhere you also need to factor in your own mods internal resistance although on most regulated devices I would assume the chip accounts for this?)
I'll post a follow up after this of all the metals common TCRs
3) Temperature - this is what you want your mod to max out at and stay at when it gets there ...meeting all of those things I listed above (avoid cremating cotton etc)... now it's important to note your mod isnt actually detecting the temperature, it's carrying out calculations 1000's times a second based on reading the starting ohm resistance and the resistance while heating this is why TCR is important..(it's also really important you have a good connection on your deck for your coils as well, dodgy ohm readings to start with are bad news, health and safety first people)
Example:
- A coil is at 0.10Ω at room temperature (20°C / 68°F)
- You vape and the chip sees its resistance is now 0.22Ω
- So it knows its resistance rose by 0.12Ω
- Then it calculates using the TCR you pre set of 0.006 (NI200) thats a resistance rise of 0.12Ω equals a temperature rise of 200°C (392° F)
- And therefore the coil temperature is now 220°C (428°F)
- (0.22Ω - 0.10Ω) / (0.006 * 0.1Ω) = 200°C (392°F)
- + 20°C (68°F) [starting temp] = 220°C (428°F) [coil temp]
4) Wattage - This is serving to only get you to the temperature you set earlier because your mod will maintain temperature when it's peaked (that's why you see that temp message on your mod) it's pulsing here to maintain temp rather than keeping going in power mode, it's not turning off like a lot of people think ....
So set this based on how quickly you want to reach your max temp, if like me your not fussed on the pulsing bit set it lower, if you want it at max level immediately raise it there is no right or wrong
No doubt there are things I've forgotten or don't yet know so Q&A time guys
I'd like to take my hat off to Steve
@Wingsfan0310 for helping me complete this picture
Edit: found a really useful article which has a very thourough explanation of all the elements affecting TC well worth a read
https://www.ecigssa.co.za/guide-to-fine-tuning-temp-control-vaping.t18206/