Watts do not matter. Its all about wire temp. Read on

[gdeal]

Yes that’s right.

Watts as means for communicating a best vape, or preferred vape only matters if the same product, with same consistent reproducible criteria is compared. Some commercial products have semi-adequate quality control that permit, to a limited extent, such comparisons. juice type, juice viscosity and a host of other factors such as tank pressure, airflow etc can affect these comparisons as well.

While we have all these factors, for modders and those that use genny type attys there is desire to understand and reproduce one person’s set-up and compare to our own results independent of hardware.

There is a growing trend to look toward watts as a way to further refine our ability to explain how to set-up a certain configuration on a mod or atty. I can’t tell you how many post I have read that one person has a sweet spot at 8 watts or another that likes to vape at an “unbelievable” 20 watts. This is a good direction but does not get to the heart of the matter.

What I believe is important to understand is how much power is being applied to our coils and the temperature at the wire level. And more specifically how much power (and how temperature) is being delivered over the length of a coil and the wick.

Let me explain further with an example.

A 5 wrap 32g coil and an 11 wrap 28g coil can provide about ~8.5 watts when we apply 4.1v to the 32g and 3.8v to the 28g.
While 28g requires a bit more amps to drive the same watt level, the amp requirement of 28g can be up to 2x of the 32g to achieve the same wire temperature.

Yes, a 28g wire will be cooler at the same power levels (watt) compared to a 32g wire. (even more so with wick material and juice heat sink.)
So while we are not able to reasonable measure wire temperature with current technology we can advance our discussion, using empirical data to refine our thinking.

Let’s compare a 28g coil on a genny vs a 32g coil on a genny.

I am using a “Chud”. A $15 buck chinese mystery metal apparatus that has a wick hole of ~2.5mm. I am using #500 SS mesh so we eliminate wicking issues.

Using the same wick for both set ups I created a 28g 11 wrap coil for 1.7 ohm and a 32g 5 wrap coil for 2.0 ohm both have the same interwire distance (coil pitch).

The 28g produces 8.5 watts at 3.8v and 10.4 watts at 4.2v
The 32g produces 8.4 watts at 4.1v and 10.4 watts at 4.5v

So while we can match watts on each coil with volts. The 28g coil covers more than 2x the wick surface than a 32g coil.

If we look at power distributed over the wire:
The 28g coil has 90mm wire length and 32g coil is 41mm

So for 28g we have:
.09 watts per mm at 8.4 watts total power output, and
.12 watts per mm at 10.4 watts watts total power output

For 32g the coil:
.20 watts per mm at 8.5 watts total power output
.25 watts per mm at 10.4 watts total power output

Right now, technology does not allow us to feasible determine real life live wire temp. But, from my subjective experience, I get more vapor, more consistent taste from the 28g coil at the same wattage but lower wire temperature. I can even say that at 14 watts (I am using a Provari so I am limited) that the 28g coil producing .15 watts per mm is more robust than 8.5 watts on a 32g coil at .20 watts per mm and the .25 watt per mm at a total of 10 watts.

I believe the reason for this is the thermal zone created around the wire to create vaporization. With 28g you are applying less power per mm but over a larger coiled area. With 32g you need to apply greater power to increase the thermal zone to force more vaporization. However, temperature is not distributed evenly over the thermal zone with the example 32g and 28g coils. Temperature diminishes along its radial projection. So while you are gaining a larger vaporization zone around the wire by increasing power, the variance in temperature is greater. The more you up power on the 32g the larger the gradient and the more likelihood you will burn the juice closer to your coil. If you have a higher gradient of temperature ranges you will have a more vapor, but it will be a mix of “burnt” taste and just right taste. With 28g vs 32g you can achieve a similar wire temp, but given our atty parameter restrictions, you can achieve a tighter more consistent temperature zone with a larger/longer 28g coil.

So what about those gonzo vaporers who are tricked out at 20 watts? For example, let say they are using 28g with 6 wrap coil for 1.0 ohm resistance. First, they have to have a power source to be able to deliver 4.5 amps. So how are they doing from a power on wire perspective? Based upon coil calcs for this example, their coiled wire is about 49mm. So they are putting .4 watts per mm on the wire. That twice almost twice the power of the 32g wire! How are they not burning their juice? Well thicker wire requires more amps to reach the same operating temperature.

While I only have a source for Nicrome wire temps. (Resistance Wire.Com | Nickel Chrome, Nickel Copper, and Iron Chrome Aluminum Alloys from Stock), I assume that a similar coefficient exist for Kanthal. I assume to some extent the same principle applies. For Nichrome it is ~2x. So if the same principle exists for Kanthal, they are really using the 32g equivalent of .2 watts per mm on the wire. Probable less of a mix of “burnt” taste and just right taste than 32g, because their vaporization zone will be more dense, produce vapor quicker and their “power-on” time will be less.

Now that a majority of readers have their eyes glazing over…the short of my take-aways are:

• More coil on wick = better
• More consistent/lower coil temp = better
• 28g coil for coil/watt for watt better than 32g

These are just rambling musings while I wait in the aftermath of Sandy for my power to come back on. Thank god I have a portable generator to keep my batteries charged. If this post is incoherent, blame the ethanol that did not make it into my ejuice for dilution/throat hit.

I am sure that the “veterans” on this forum can explain this better (and more concisely) and even point out the short comings of my logic.

I guess the inquiry here is that perhaps there is a technical solution that is beyond my education and experience and how do we build this into our devices.

 

[BJ43]

Thanks gdeal. Very well explained.....

 

[Dan Patrick]

Yeah I understand that. I really need some 28. But will 26 be all the rage tomorrow? I have 32, 30 and 400 mesh. Now I need 500 mesh and 28. Is this the be all end all or is ceramic and 100g kanthal next! What a hobby!

 

[mwa102464]

gdeal,

This is well kown about the wire, but good post, if you go to Kanthal.com you can get those specs on the Kanthal wire you dont have, they also have a handbook that goes over much of this. It's also why they use different guage wire in LR,SR,HV Attys much of the time, but yes the 28AWG Kanthal is very good. I've made coils with even lower AWG Kanthal that have looked like a heavy duty spring trying to get better juice flavors but the problem is you run out of room, they look like heating elements more than a Atty coil too like the one below =

This coil was made from 24AWG Kanthal and man does it produce some serious flavor,, but finding things to use it in is limited because of how many coils I needed ( I think that one was 13 coils when finished ) vs how much room I have to play with. I would love to see a Genesis Atty made with more room between the mesh wick and center pole, as well as a longer center pole with more head room to explore more of my coils I have made and tested out. It's probably only a matter of time before a modder makes a Genesis unit with more room like we need to make these coils, anyways I tend to fully agree about the wire, good post,,, but Watts are still a good source combined with great electronics which seem to keep improving too, we still need the power sources to drive the wire, but the wire does matter and making up these super coils as I call them, they work, but how far is far enough to create a great vape ? and we then get to a danger zone with Amp draw and how much the Batts can handle, then we have people making coils that dont know what there doing, we need to be careful here with this in my opinion, but it's a good thread to discuss coils and wire for sure. Good post.

 

[Lance_Wallen]

I think 28awg is going to be the butter zone just ebcause of limitations in electronics. The form factor of the genesis needs to evolve though to accomodate this gauge as it's difficult to get a sufficient coil in existing form factors. Wicking distance will be a factor too, even with 500mesh an extremely long coil and an aggressive vaper is going to run into wicking 'height' issues. I finally got my set up working, to me... the oxidization and shorting issues are a big concern because of the reliability of creating a coil that doesn't short on SS wicking material.

 

[WillyB]

The popular Cisco coils quickly come to mind.

Same ohms, which one is the Cisco?


What is a watt?

The watt (abbreviated W) is the International System of Units' (SI) standard unit of power (energy per unit time), the equivalent of one joule per second. The watt is used to specify the rate at which electrical energy is dissipated, or the rate at which electromagnetic energy is radiated, absorbed, or dissipated.

A question from some physics forum.

How much heat does 10 watts equal in terms of temperature?

Answer:

It doesn't tell you much without knowing where those 10 joules per second are going. Heat is related to temperature by the calorimetric equation

Q = mCT

where Q is the heat exchanged, m is the mass, C is the specific heat constant of the substance and T is the temperature change. So depending on what you're heating with that 10W, you will end up with different temperature changes (e.g. it's easier to heat 1 gallon of air than 1 gallon of water).

From the early says of the Darwin craze the whole notion that we vape 'watts' stuck in my crow.

I think 28awg is going to be the butter zone just ebcause of limitations in electronics. The form factor of the genesis needs to evolve though to accomodate this gauge as it's difficult to get a sufficient coil in existing form factors. Wicking distance will be a factor too, even with 500mesh an extremely long coil and an aggressive vaper is going to run into wicking 'height' issues.

You sure? Have you noticed how many of the new breed Genesis vapers produce those clouds?



The 'drinking a beer' technique.

 

[martinc]

gdeal,

This is well kown about the wire, but good post, if you go to Kanthal.com you can get those specs on the Kanthal wire you dont have, they also have a handbook that goes over much of this. It's also why they use different guage wire in LR,SR,HV Attys much of the time, but yes the 28AWG Kanthal is very good. I've made coils with even lower AWG Kanthal that have looked like a heavy duty spring trying to get better juice flavors but the problem is you run out of room, they look like heating elements more than a Atty coil too like the one below =

This coil was made from 24AWG Kanthal and man does it produce some serious flavor,, but finding things to use it in is limited because of how many coils I needed ( I think that one was 13 coils when finished ) vs how much room I have to play with. I would love to see a Genesis Atty made with more room between the mesh wick and center pole, as well as a longer center pole with more head room to explore more of my coils I have made and tested out. It's probably only a matter of time before a modder makes a Genesis unit with more room like we need to make these coils, anyways I tend to fully agree about the wire, good post,,, but Watts are still a good source combined with great electronics which seem to keep improving too, we still need the power sources to drive the wire, but the wire does matter and making up these super coils as I call them, they work, but how far is far enough to create a great vape ? and we then get to a danger zone with Amp draw and how much the Batts can handle, then we have people making coils that dont know what there doing, we need to be careful here with this in my opinion, but it's a good thread to discuss coils and wire for sure. Good post.

Easy,find the biggest genesis you can lay hands on,wrap a Uwick ...then you will have all the area required for a 15 windings coil if you so desire.

 

[Lance_Wallen]

Willy:

That doesn't negate my wicking height issue I'm talking about the vertical wicking capability of the mesh is going to be a limiting factor to increasing coil length, etc. I can use 325 mesh rolled loose and tip it to get juice for a 1 second pull.

The catch here is that in a genesis if you have an 'open' hole or loose wick and you lay your device on it's side you can leak or flood, so the move has been to plug holes, use tight wicks, etc. At which point capilary action is what you're after, not gravity. The video you linked is gravity in action and that's perfectly fine and acceptable. I'd rather not have to tip if I can get away with it because I don't want to 'think' about vapin. I just want to do it. Which means when I pick up my device, if theres juice in it I want to be able to take a toot and not be surprised with a dry hit cause I didn't tilt it right or I left it standing vertical on my desk.

 

[Lance_Wallen]

also, I think dual wick, single coil is the future

 

[zengargoyle]

... Which means when I pick up my device, if theres juice in it I want to be able to take a toot and not be surprised with a dry hit cause I didn't tilt it right or I left it standing vertical on my desk.

Micro pumps! maybe piezoelectric or just rare earth magnet + electromagnetic coil on a membrane that pumps juice up a tiny tube at a tuneable rate. We do have power y'know.

Anyway, nice thread. Glad I'm not crazy, I've been thinking for a couple of weeks now after getting a Phoenix RBA and wrapping coils for it and Vivi Nova and T2 heads that longer coils of fatter wires would make things better. If you go the other way you end up with pumping 8W into a laser point and all I can see is a flash of hot air with little vapor. Going the other way there must be some point where the power is spread just right to produce the most vapor.

 

[mwa102464]

Been there done it Martinc, I came to the conclusion that to much wire is just as bad as not enough at a certain point, there is a happy medium to my findings in regards to wire and making coils for the standard Genesis Atty's we currently see on the market. The problem I run into is wicking with 12-15 coils in the heavier gauge wire, it came to a point I basically had to lay the coil in a puddle of liquid to get the proper vape. Now if someone came out with something more in the lines of those fog machines but a mini fogger that we used to vape, well then we may have something there, but these little tanks with a 2mm -4mm mesh wick just wasn't cutting it, I have laid my coils horizontal in a lot of liquid and had some very good results with my bigger super coils, but vertical they just cant keep up with wicking. Now if someone would want to make a tank that held a super coil horizontal, and it laid in the top part of the liquid in a holding tank, we would surely have something here in my opinion, I feel it would have to be a tank inside of a tank with the outer tank allowing liquid to come into where the coil was and the liquid pooled up into a pool and the coil sat there at the top part of the pool. Or, if using a vertical coil the same thing kind of, the wick coming straight up and sitting inside of a small surround filled with liquid that got filled up either by taking a draw or from an outer tank filling the inner where the big coil/mesh sits would be even better, so the bigger wire coil/mesh sat inside of a housing that was filled with liquid in order to wick enough mesh for a massive coil. I have some pretty good current designs and would enjoy getting with a new machinist to make a couple of Beta systems. Maybe someone will see this and do just that

I made a suggestion in another thread a ways back, for the modders to make an SS tube that screwed down over the mesh wick, this would work I feel with one of these bigger coils especially, that tube that covered the mesh wick could fill with liquid when holding your Genesis unit horizontal and house enough liquid in and around the mesh for these bigger coils to work/wick properly.

 

[Lance_Wallen]

ooh, lazer vaporizer.... no more heating coil, just a lazer that zaps the juice.

 

[Lance_Wallen]

*snip*
Now if someone would want to make a tank that held a super coil horizontal, and it laid in the top part of the liquid in a holding tank, we would surely have something here in my opinion, I feel it would have to be a tank inside of a tank with the outer tank allowing liquid to come into where the coil was and the liquid pooled up into a pool and the coil sat there at the top part of the pool. Or, if using a vertical coil the same thing kind of, the wick coming straight up and sitting inside of a small surround filled with liquid that got filled up either by taking a draw or from an outer tank filling the inner where the big coil/mesh sits would be even better, so the bigger wire coil/mesh sat inside of a housing that was filled with liquid in order to wick enough mesh for a massive coil. I have some pretty good current designs and would enjoy getting with a new machinist to make a couple of Beta systems. Maybe someone will see this and do just that

instead of one fat super wick, why not multiple wicks with a single coil that goes around each in a figure 8 or a triskele pattern? You'll get more surface area that way. It's part of one of my test designs I've sketched but not had the time to try and create. Basically a genny but with 2 3mm wicks real close to each other and a single strand of wire wrapped in a figure 8 around the two wicks.

 

[mwa102464]

Multiple wicks are already out, not needed in my opinion if you can use one bigger coil, you also need more room to use the lower AWG wire Lance, more coils and smaller wont work like I'm discussing, we need more room for the lower AWG Kanthal wire to support enough ohms = 12-15 coils worth of room

 

[BJ43]

also, I think dual wick, single coil is the future

Nave been using dual wicks on my cheap lines with figure 8 wrap for a long time, here is one on a Gtank.

 

[gdeal]

if you go to Kanthal.com you can get those specs on the Kanthal wire you dont have, they also have a handbook that goes over much of this

.

MWA...Thanks for the response. I read quite a bit over at Kanthal.com and reviewed the handbook. I also tried a broader internet search. I could not find data/table that provided the amp/temperature relationship for kanthal wire. If you or anyone else can point me in the right direction for a source, it would be appreciated.

.... we still need the power sources to drive the wire, but the wire does matter and making up these super coils as I call them, they work,

I have seen your super coils, they were one of the reasons why I initially started trying to get my head around this issue.

but how far is far enough to create a great vape

Ugh..I thought you would have that answer...

 

[asdaq]

BJ, how is it performing? I saw something along those lines on UKvapers, but the air inlet wasn't worked out so well. I was thinking of something like that but with the wick holes close to each other that the wicks are still straight and with just enough room between for the figure 8 intersections. A single inlet as per single wick setups, directed low at the center of the whole construction to harvest the lovely vapor. So, you think it's worth the fuss?

 

[mwa102464]

The Cobra's are built stock to accept dual wicks or run a single, I run two of them but it can be more hassle then its worth at times, and running one 28AWG seems to be more worth while to me.

 

[slin]

Learning everyday, today is no different. Thank you for the lesson, keep my interest in vaping going. This community is getting better and better.

 

[asdaq]

I've seen quite a few multi-hole arrangements, but not yet with ~1mm spacing between holes. They could be close enough to trap liquid between them from surface tension and proximity.