Hi Mac,
What is your opinion on the difference in performance, flavor and heating properties between doing a single wire coil vs. twisted wire coil? I'm interested in your scientific insights! Advantage of one over the other?
Wanted to take a few and get back to ya fellas. As I told Matty on the Tensioned Next thread, it's time to flip this problem over on its head and look at its bottom. Were so used to looking at resistance and power as an index that we fail to consider how it's utilized. IOW, the net performance that were getting.
It is all about the temperature. But not the overall output of the wire or even the build overall. It is about effectively directing the wind's energy towards phase transition.
First inclination might be to just double up a wire spec, say 32AWG. With half the res we should see more performance. But that actually would produce a cooler vape even at half the resistance as
@TheKiwi (Thank You!) explained in some detail in the blog post
Coils: Do thicker wires ACTUALLY give you a warmer vape?
In conclusion, using thicker gauge wires DO NOT naturally lead to a warmer vape. On the contrary, there are far more cases when using a thicker gauge wires will lead to a cooler vape. THE ONLY way that thicker gauge wires can give you a warmer vape, is if you overcome the increase in heat capacity of the coil by exponentially increasing the wattage supplied to the build (e.g. lowering the resistance of the build to draw more current).
The only thing that matters I believe is
the thermal zone we create
at the interior of the wind. And a car analogy is helpful here — the contact patch. Nowhere else. It's where the rubber meets the road. Where we get
real traction. And for our purposes, the most important, the contact surface.
There's a total mis-appreciation of what that is though and consequently an overestimation which leaves us constantly short and seeking more power. And I find this really curious if you read my above analogy that it's not obvious to all, only the contact of wire to wick is meaningful here. So when I look at the numbers from a steam-engine.com for example, I find some helpful others misleading.
For example, in comparing wire for the surface area of a twisted pair and a parallel (dual coil), or round vs. twisted, there is a difference in surface area. It's not clear how the numbers are derived; but to me, the surface area of the threads is the same. S-E computes
the overall circumference of a twisted pair AS IF it were equivalent to a wire twice it's diameter, e.g. 26 and 32 AWG but this is in my estimation incorrect. The available surface area is no more than there physically is. This extrapolation suggests that twisted presents the same surface area as a comparable straight wire. It does not.
To my thinking because of the rotation of twisted the surface of one wire is presented then alternatively the surface area for two. You have an interspersed contact with the wick which effectively reduces the contact area by roughly 25%. Perhaps my logic is flawed here but I don't think I'm too far off from the mark. That said, straight wire of comparable mass must present more contact with it's more contiguous surface. Likewise flat-wire having the same advantage over round wire.
So the popular legend that twisted pair is the automatic ticket to better flavor or production (as having more surface area) seems unfounded based on the straight-up numbers (it's a matter of relevant calculation approach). And fat, wide, spread all suffer from the downside of inefficiency based on lack of contact concentration relative to essentially wind height.
However,
what if you could lay down the flatter context of the thinner gauge? Why then you'd have a parallel wind.
And why does this matter?
We vent a lot of our power on thick wire builds. That's why we must increase amps as @TheWiki explained. So there's a scale of diminishing return here for
actual vaporization which decreases as the ratio of
loop circumference increases compared to the actual contact area in mm2. The greater the contact patch relative to overall wire dimension the more potential thermal conductance. So understanding the
contact mechanics may help us make better decisions in our wire/wind choices regarding overall production and what is most conducive to either density or dispersion. That is my perspective.
Good luck all.
