Right, then the atomizer would not be operating ... which is why I specified "operational" condition. It is relevant since that is the purpose of atomizers. The pre-operational condition (or sub-operational condition) can differ between coils, which would manifest as responsiveness.
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Right, then the atomizer would not be operating ... which is why I specified "operational" condition. It is relevant since that is the purpose of atomizers. The pre-operational condition (or sub-operational condition) can differ between coils, which would manifest as responsiveness.
So what would be the secret that would make a 2 ohm 28g thick long coil vape the same as a 2ohm 36g short thin coil at the same 10 watts?
Here is some magic.....err...I mean science/math.
To put some numbers around this, you can look at relative Watt Densities.
"Watt Density is the wattage of an element per unit of surface heated area and indicates the potential to transmit heat."
For a 2 ohm coil
32g requires a 1.74 inch length of Kanthal A1
28g requires a 4.34 inch length of Kanthal A1
The formula for Watt Density is: Total Wattage/(Wire diameter x Heated length x 3.14)
32g has a diameter of .00795 inches
28g has a diameter of .0126 inches
Calculations:
32g
10 watts of power = Watt density of 230 w/sq in
20 watts of power = Watt density of 460 w/sq in
28g
10 watts of power = Watt density of 58 w/sq in
20 watts of power = Watt density of 116 w/sq in
So while this tells us that 28g wire will run cooler, the only way to really compare the impact is to have the same type of set up. (Atty, wick material and size, juice, coil configuration and airflow.)
For example the surface area of micro-coil of 28g wire will get hotter than a standard 28g wire in a genny set up with spaced out inter coil distances. This is due to effectively reducing the surface area of the wire that will transmit heat energy. If the coil is pinched together tight so that coils touch each other you can eliminate almost 50% of the available surface area.
What is interesting is that even with a micro coil of 28g, it will still run cooler than 32g.
I don't think given our materials and limited parameters that you can make 32g (or 36g) wire perform like 28g or vice-versa.
To put some numbers around this, you can look at relative Watt Densities.
"Watt Density is the wattage of an element per unit of surface heated area and indicates the potential to transmit heat."
For a 2 ohm coil
32g requires a 1.74 inch length of Kanthal A1
28g requires a 4.34 inch length of Kanthal A1
The formula for Watt Density is: Total Wattage/(Wire diameter x Heated length x 3.14)
32g has a diameter of .00795 inches
28g has a diameter of .0126 inches
Calculations:
32g
10 watts of power = Watt density of 230 w/sq in
20 watts of power = Watt density of 460 w/sq in
28g
10 watts of power = Watt density of 58 w/sq in
20 watts of power = Watt density of 116 w/sq in
So while this tells us that 28g wire will run cooler, the only way to really compare the impact is to have the same type of set up. (Atty, wick material and size, juice, coil configuration and airflow.)
For example the surface area of micro-coil of 28g wire will get hotter than a standard 28g wire in a genny set up with spaced out inter coil distances. This is due to effectively reducing the surface area of the wire that will transmit heat energy. If the coil is pinched together tight so that coils touch each other you can eliminate almost 50% of the available surface area.
What is interesting is that even with a micro coil of 28g, it will still run cooler than 32g.
I don't think given our materials and limited parameters that you can make 32g (or 36g) wire perform like 28g or vice-versa.
Thermal coupling takes place at all the theoretical juice contact points on the coil, at equal wattage it is impossible for all the theoretical points on 28g 2ohm coil to be as hot as the theoretical points on a 2ohm 36g coil....
Choking the air feed maybe, stacking the coils ("micro"coils), maybe choking the juice supply. IMO the question is more how to get a 36g coil to keep up with 10w.
If both coils can reach the boiling point of the juice, then they will both be the same temperature.
The point of this thread is about how watts do not matter, it is the temp of the wire on the coil. So you just answered the point. To get a 2ohm 28g coil to get to vapor temp takes more watts than to get a 32 g 2ohm. So those who say that the same watts with different ohms gives the same results are fooling themselves. As far as both having the same temp that is false, this is not the water boiling in a bag trick, the coil with more power can get much hotter and even burn and flash flame the juice. Really this is about thermodynamics and not about choking the juice supply or stacking coils. It has nothing to do with whether a 36 g 2 ohm will withstand 10 watts. When VWs came out they were advertised that no matter what atty or ohms you put on them, if your sweet spot was 8 watts, they would all vape the same and this thread was a way to disprove that myth.
Here are the #s.
http://www.e-cigarette-forum.com/fo...all-about-wire-temp-read-23.html#post10573667
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As discussed previously... The temperature may be the same but the amount of heat being transferred to the wick & juice is very different.
For a given voltage / resistance combination, the thinner wire will produce more heat than thicker wire.
For a given voltage / resistance combination, the thinner wire will produce more heat than thicker wire.
Honestly I don't care if it is or isn't... It's the actual, physical, temperature is irrelevant. Even if the measured temperature remains the same, it doesn't mean that the amount of heat energy being imparted into the system remains constant. It's the heat energy that vaporizes juice not temperature... Temperature is simply a measurement of heat energy (that, depending on the environment, doesn't necessarily reflect the true amount of energy being generated).
Going round and round about "temperature" is just squabbling over semantics.
Jas90, you got me confused.....At a given voltage/resistance combination how can a thinner wire produce more heat? Wattage is wattage.
The intent of the thread was as BJ43 stated, to highlight an incorrect use of communicating how we vape. While 8 watts is 8 watts, it really is meaningless unless you know the context in which the power is being used. The differentiating factor I used was wire temp, not the heat in the system. Putting 8 watts into a system on either 28g or 32g is the same on a macro level. But the dynamic is occurring at the micro level. Its the heat at the wire level, where the juice is being vaporized. If you had unlimited juice supply going to coil, then there wouldnt be a big difference in wire temp. But since our wicks wick, typically through capillary action, there is an effect that occur when juice is vaporized.
Without getting all into the science, what can happen more often with thinner wire than thicker wire is a "dry-out" effect. Essentially vapor displaces juice in the wick. This is a more focused effect with thinner wire. Effectively juice can not get back to the heat source, to cool the wire. When pushed beyond a threshold capability, the wick can not recover and wire temp will rise. The distributed heat over greater surface is one of the reasons why 28g vapes so much better than 32g.
So maintenance of the right wire temperature, (what ever that may be...) is the core variable to target.
Wattage is wattage... But thinner wire requires fewer watts to achieve a given temperature than thicker wire, for any given resistance. That's "coils 101" stuff...
I agree with the first part... The second is a bit off... Temperature is a measure of the heat in the system. But... As was pointed out earlier, there's is good evidence that the temperature of a wet coil won't actually exceed the boiling temperature of the liquid, while it's wet...
My point is, who gives a crap weather or not the "temperature" of a wet coil is capped? You may not be able raise the "temperature" but you can certainly continue to add energy.
Actually there is a huge difference. A 2 ohm coil wrapped with 28 awg wire has a great deal more thermal mass and much greater current carrying ability than a 2 ohm coil wrapped with 32 awg wire.
By "current carrying ability" I'm referring to a wires ability to carry current w/o getting hot. This is the same reason teeny tiny SMD resistors have lower wattage ratings than larger resistors, for a given resistance. Same reason housing codes specify certain wire gauges when wiring a house. You can use thicker wire than the code specifies without a problem. If you uses thinner wire than the code allows, you'll be yanking it out...
The reason it dries out faster is because the wire gets hotter...
Kind of my point... I really don't care if you call it "temperature" or "energy". The net effect is the same regardless of the terminology.
No they're not. You saying that without knowing how the person achieved the resistance is the one who is fooling himself.
Around the proper operating temperature of the atomizer, it absolutely is the water boiling in a bag trick. Below or above that are sub- or super-operating conditions, in other words, the atomizer is not functioning properly. Those conditions are not valid proof of a point in the context of this discussion.
Again the function of the atomizer is to change the phase of the liquid.
The reason it gets hotter is because it enters super-operational conditions, but that is not related to the heat density in the wire per se. It's likely more a fluid dynamic issue related to the size of the wire and its position on the wick. That is why stacked coils handle more power than spaced.
If you can keep the coil wet, it won't get hotter.
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Again with the f-ing semantics... The coil's temperature may not increase but that doesn't mean that there's a cap being put on the amount of heat being generated.
Same thing with boiling water in a pan... The temperature of the bottom of the pan may not exceed the boiling temp of the water, but I can sure as shti make the boil faster and more violently by turning the knob on my stove up to 9.
Same thing with boiling water in a pan... The temperature of the bottom of the pan may not exceed the boiling temp of the water, but I can sure as shti make the boil faster and more violently by turning the knob on my stove up to 9.
Come on people!!! This is a bunch of semantics and over reaching...read between the lines and the whole thread.
I'm pretty sure I know what BJ meant and its not how drg implied it.
IMHO Jasl is basically saying what this thread is all about.
Am I missing something?
Here is my basic understand of this thread....There are so many variables in today's attys (espicially rebuildables) that you can not simply rely on the same wattage to give you the same performance from one setup to another.
Did I miss the point of this thread?
I'm pretty sure I know what BJ meant and its not how drg implied it.
IMHO Jasl is basically saying what this thread is all about.
Am I missing something?
Here is my basic understand of this thread....There are so many variables in today's attys (espicially rebuildables) that you can not simply rely on the same wattage to give you the same performance from one setup to another.
Did I miss the point of this thread?
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You are thinking inside the box with two different coils wrapped around a same wick. A silica wick behaves differently than a stainless mesh wick which behaves differently than a stainless rope wick which behaves differently than no wick and just juice which behaves differently than a wire heating a high efficiency heat sink wetted with juice which is very different than . . . . It is not only very possible but very simple to make 2 differnt atomizing assemblies that will meet your stated criteria. It's no more than getting the heat into the juice.
I think you pretty much nailed it... Except for the "so many variables" part...
If you limit the topic to the coil portion of the atomizer only, I don't think there's that many variables...
Wire gauge is pretty much it... Or at least 90% of it.
Talking a bout watts would make sense if we were all using the same wire gauge in our attys. At least in theory, applying 10 watts to a 1.5 ohm coil wrapped w 32 awg wire should be similar to 10 watts applied to a 2.5 ohm coil wrapped with 32 awg wire. So... If two people are using the exact same wire, they can talk in watts to make comparisons.
The point of this thread (at least what I take away from it...) is the fact that comparing watts is pointless if one person is using 36 awg wire and the other is using 28 awg wire. The wattage requirements between the two wires is so drastically different that comparing wattages is completely irrelevant.
A person using and off the shelf carto would gag at the thought of vaping at 15 watts. The heat would be unreal. Another person using an RBA coiled with 28 awg wire, on the other hand, would likely find 15 watts a little on the cool side.
It's really pretty simple IMO. All were really doing is making VERY simple resistors.
The problems start when people try to make it more complex than it really is. There is no mystical Kung-fu art of coil wrapping.
For any given "fixed" power source and a given coil resistance... The thinner the wire, the hotter it will get and the faster it will get hot. That said, the thicker the wire, the more turns of you'll be able to put on while maintaining the same resistance.
If there's any art to it at all, it's finding the wire gauge / resistance combo that works with your PV to give you the vape experience that you enjoy most.
Just my 2 cents...
I think where it ended up (at least in my mind) is that wire temp can be a good indicator of wicking efficiency. How much wattage before burnt taste will likewise give a good indicator of the same and burnt taste is another way of saying hot wire. A lot of the discussion back and forth (which is pretty darn good) relates to why that is so. It's important understanding the why because that's the most fundamental basic of making an atomizer (hopefully a better atomizer). All we're really doing is boiling liquid but ideally at a quench front where a small amount of liquid flash boils. If the coils gets much hotter than the boiling point of the juice due to insufficient quenching (inadequate wicking for the coil), the juice will taste burnt. That's about it so far.
Other things to think about start with the wick reservoir and thermal coupling. If the coupling really sucks, even a wet wick will taste burnt so can ignore wicking if the even tiny reservoir of juice already in the wick can't get atomized without tasting burnt. Next is air flow which also cools the atomizer. I don't think we got that far yet. Where we got is complicated enough lol.
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@jasl - I would agree, if you only limit it to the coil. But IMO the coil is the easy part. Wick/liquid delivery has been the most inconsistent variable for me. I swear I could wrap the "same" coil on the "same" wick 10 times and likely there would be a slight variance across the 10 wicks. Maybe I'm just not consistent enough.
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