Same wattage different ohms what is the difference?

[eddykoodoo]

Let's say you are vaping at 4.2 volt with a 1.8 ohm coil wattage would be 9.8 watts

If you vape at 3.4 volt with a much lower resistance 1.2 ohm coil the wattage stay more or less the same even a bit lower 9.62 watts.

Basically what is the difference in term of vaping experience same wattage but different ohms?

VapeCalc

 

[sonicbomb]

If the coils had the same surface area then yes. Though the lower resistance coil would probably have a marginally slower ramp up time as it would probably have a higher mass.

More watts for wider coils?

"Try to think of the power level dictating the wire guage and end resistance..
If you want to use a lot of wattage then you need a heavier gauge of wire to be able handle this power. Heavier wire, more mass (and possibly greater surface area), intrinsically lower electrical resistance.
If you want to use a far lower power level, then you need a much thinner wire with less mass, or your power level will not be sufficient to light it up. Thinner wire, higher resistance.
It's about having a coil mass to suit the chosen power level, not the other way around, with a regulated device anyway.

You could put 12 watts through a 0.25 ohm dual 24G coil, but it would barely vape and the ramp up would be measured in minutes.
Alternately you could put 70 watts through a single 6 wrap 30G 1.8 ohm coil, it would produce a hideously harsh vape and probably melt."

Also have a read through this thread, particularly the first post as it helps to explain the relationship between coil mass, surface area and heatflux.
My thoughts about sub-ohm and latest VV/VW devices...

 

[Bunnykiller]

hmmm same watts but different coils... the lower volt, lower ohm setup will draw more current, thus making the batteries run out quicker...

 

[zoiDman]

Let's say you are vaping at 4.2 volt with a 1.8 ohm coil wattage would be 9.8 watts

If you vape at 3.4 volt with a much lower resistance 1.2 ohm coil the wattage stay more or less the same even a bit lower 9.62 watts.

Basically what is the difference in term of vaping experience same wattage but different ohms?

VapeCalc

If the Wire Type and Gauge stays the Same, then the 1.2 Ohm coil should run "Hotter" @ 9.62 watts then the 1.8 Ohm coil at 9.8 Watts.

Try plugging in your Numbers into this Calculator and notice how the "Heat Flux" changes.

Coil wrapping

 

[Grimwald]

As others have said, results are more dependent on wire gauge. Thicker wire will need more power to ramp up. I prefer to conserve battery life and get immediate vapor, so I usually use 30ga wire at 1.5-1.8 ohms (6-7 wraps) and 8-10 watts. Others may want more surface area so use thicker wire, more wraps and more power.

 

[vapdivrr]

Let's say you are vaping at 4.2 volt with a 1.8 ohm coil wattage would be 9.8 watts

If you vape at 3.4 volt with a much lower resistance 1.2 ohm coil the wattage stay more or less the same even a bit lower 9.62 watts.

Basically what is the difference in term of vaping experience same wattage but different ohms?

VapeCalc

As others mentioned , there is more to it then just a simple example, but in your exact examples, with basic 28g wire let's say, the differences would not be much. A 1.8 vs a 1.2 ohm coil with the same wire gauge and same wattage would be barely detectable.

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[mcclintock]

As others mentioned , there is more to it then just a simple example, but in your exact examples, with basic 28g wire let's say, the differences would not be much. A 1.8 vs a 1.2 ohm coil with the same wire gauge and same wattage would be barely detectable.

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Actually it would be huge, good example, the 1.2 ohm coil has only 2/3rds the wire, much hotter, like 50% higher power density. Only if the device and actual power level were suitable would it matter. If the atomizer favors the larger coil and more power, either the 1.2 would burn and the 1.8 be good, or at a lower power the 1.2 would work but be weaker. If the atomizer favors the smaller coil, airflow limited, the larger 1.8 wouldn't allow much more power but it would be slower and heat the air more.

Another example is different resistance wires. If the coil is the same size in every way, and the power is the same, changing the resistance doesn't change the vape. It may be slightly less efficient, but variable voltage mods can convert power to a non-battery voltage with little loss, within reason.

 

[vapdivrr]

Actually it would be huge, good example, the 1.2 ohm coil has only 2/3rds the wire, much hotter, like 50% higher power density. Only if the device and actual power level were suitable would it matter. If the atomizer favors the larger coil and more power, either the 1.2 would burn and the 1.8 be good, or at a lower power the 1.2 would work but be weaker. If the atomizer favors the smaller coil, airflow limited, the larger 1.8 wouldn't allow much more power but it would be slower and heat the air more.

Another example is different resistance wires. If the coil is the same size in every way, and the power is the same, changing the resistance doesn't change the vape. It may be slightly less efficient, but variable voltage mods can convert power to a non-battery voltage with little loss, within reason.

No way, totally disagree... a 1.2 vs 1.8 . Yes I agree at the same power the 1.2 will be a bit faster , but still not a major difference.

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[smacuser]

Power to the coil.

 

[TheLawbird]

I think that in order to really understand, it helps to use drastic differences as
examples.
Here's my analogy.
We have two equal runners about to run for 10 seconds, they both have to exert the same amount of effort for the whole 10 seconds. Runner A is running against a minor wind, which is causing a resistance of let say .5
Runner B is is running against hurricane force winds causing a resistance of 2.5.

Even though they are putting in the exact same effort, runner A is going to get further with the exact same effort put in.

Now the distance the runners ran would be the analogy for wattage. But what we really want to know is how exhausted the runners are when they are done.
Wattage does not directly correlate to the amount of heat or light produced.
how exhausted the runners are would be amount of heat produced.
In order for runner B to achieve the same distance(watts) as A, he would have to put in much more effort(volts), since he is going running against much greater winds (ohms)
He is going to be incredibly exhausted, giving off a very burnt taste.
Runner A is not exhausted at all, even though he acheived the same distance(watts) his flavor is almost non existant.

In the situation that you presented where the resistances are fairly similar, if you refer to the anology, one runner is going to get exhausted slightly quicker than the other.
The 1.8 ohm coil should warm up slightly faster than the 1.2. But it'll also reach the burnt state sooner aswell. The closer they are in resistance, the less likely you are to notice.


Bonus battery safety analogy. The faster the runners move (amperage) the more likely they are to trip and fall, or at least develop a nasty case of shin splints. At a certain point if they exceed the max speed their body can safetly handle they are going to collapse.

 

[KenD]

hmmm same watts but different coils... the lower volt, lower ohm setup will draw more current, thus making the batteries run out quicker...

As we're talking about regulated mods, no, the current draw will be identical.

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[mcclintock]

No way, totally disagree... a 1.2 vs 1.8 are to close with 28g wire , both at the same wattage. If I had you take a vape off of each tank , I doubt you could tell me which were which, and if you did, the difference would be minute . Come on your telling me an extra couple wraps makes a major difference . Yes I agree at the same power the 1.2 will be a bit faster , but still not a major difference.

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How big a difference something makes depends on if the change crosses a threshold that matters. Small differences can be perceived as big, or not.

I actually use 28g 1.25 ohm on my RDA so adding that specific makes this a personal example. It corresponds to the latter case in my previous post, airflow limited, and indeed I would end up dialing up both those coils almost exactly the same power. In fact, I've ended up wanting slightly less with the larger coil. But going the other direction and taking that down to 28g .8 ohm would require a significant reduction of power. This is because, in my use, 1.2-1.3 is a sweet spot. That is, 1.2-1.3 of 28g Kanthal is my sweet spot. It has nothing to do with it being 1.2 ohm, it's the right amount of wire. I could get very similar results with about .75 ohm of #26 Kanthal, 2 ohms (guessing) of #30, 1 ohm of #28 Nichrome, or around .65 ohm of #28 SS.

 

[Bonskibon]

I recently had the same conundrum only with me it was the same resistance ohms with different gauge wire that was throwing me off. I have since learned that changing even a small fraction of the equation will give a whole different outcome. I still don't have my head fully wrapped around it, but I'm getting there.

 

[vapdivrr]

How big a difference something makes depends on if the change crosses a threshold that matters. Small differences can be perceived as big, or not.

I actually use 28g 1.25 ohm on my RDA so adding that specific makes this a personal example. It corresponds to the latter case in my previous post, airflow limited, and indeed I would end up dialing up both those coils almost exactly the same power. In fact, I've ended up wanting slightly less with the larger coil. But going the other direction and taking that down to 28g .8 ohm would require a significant reduction of power. This is because, in my use, 1.2-1.3 is a sweet spot. That is, 1.2-1.3 of 28g Kanthal is my sweet spot. It has nothing to do with it being 1.2 ohm, it's the right amount of wire. I could get very similar results with about .75 ohm of #26 Kanthal, 2 ohms (guessing) of #30, 1 ohm of #28 Nichrome, or around .65 ohm of #28 SS.

That is way to much technical explanation , I'm saying a simple thing, take 2 tanks, one with a 1.2 and one 1.8 and both let's say at 20 watts on 2 identical set ups, let me fire each and you vape each (maybe I would fire the 1.8 a half second sooner for you) I seriously doubt you could tell me which one is which. There is no way you could tell me any difference in flavor, or vapor production. Yes if you sat there and fired and vaped and thought about it for a long time maybe you could start to identify which is which, but it still is not a big difference. I'm not saying coil mass and all that technical stuff has no merit, because it does in a lot of different instances, but imo, in this example, most would never detect the difference. I also vape these examples, most of the time I do vape 28g in the 1.2 range, but sometimes I vape a 1.0 and sometimes a 1.6 and to me there is not much of a difference. I believe you if you say you can, I am not doubting you, but imo I don't think most could

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[CMD-Ky]

Too complex for me, I use SteamEngine and shoot for the heat flux (around 110 at 9 watts) I want and build to it.

 

[mcclintock]

That is way to much technical explanation , I'm saying a simple thing, take 2 tanks, one with a 1.2 and one 1.8 and both let's say at 20 watts on 2 identical set ups, let me fire each and you vape each (maybe I would fire the 1.8 a half second sooner for you) I seriously doubt you could tell me which one is which. There is no way you could tell me any difference in flavor, or vapor production. Yes if you sat there and fired and vaped and thought about it for a long time maybe you could start to identify which is which, but it still is not a big difference. I'm not saying coil mass and all that technical stuff has no merit, because it does in a lot of different instances, but imo, in this example, most would never detect the difference. I also vape these examples, most of the time I do vape 28g in the 1.2 range, but sometimes I vape a 1.0 and sometimes a 1.6 and to me there is not much of a difference. I believe you if you say you can, I am not doubting you, but imo I don't think most could

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I thought I got LESS technical
(except at the end going back to the original question)

In terms of heat flux, the difference is huge, if 20W is good on the 1.8 then 20W into the 1.2 would be like 30W on the 1.8 which has that much more size to it, more wraps or whatever (in a dry burn test they'd glow the same redness with the different settings, that's "heat flux" in action). You don't think you would notice if you set that 20W to 30W? Especially if 20W was the right one? I adjust down into the tenths of a watt. But I'm agreeing with you that lots of things can reduce that difference in a vape. The atomizer and its settings combined with your technique has a big influence and in some cases will override the coil choice. The only difference that remains is that one is being overridden more than the other. In other cases, the vape would be more similar if the power was set different between the 2 coils, to compensate for the size difference of the coils. One making up to 50% more vapor, in that case, would be somewhat noticable. Leaving the power the same could result in the smaller coil burning, very noticable, or the larger one underpowered with considerable ramp-up, noticable.

 

[vapdivrr]

I thought I got LESS technical
(except at the end going back to the original question)

In terms of heat flux, the difference is huge, if 20W is good on the 1.8 then 20W into the 1.2 would be like 30W on the 1.8 which has that much more size to it, more wraps or whatever (in a dry burn test they'd glow the same redness with the different settings, that's "heat flux" in action). You don't think you would notice if you set that 20W to 30W? Especially if 20W was the right one? I adjust down into the tenths of a watt. But I'm agreeing with you that lots of things can reduce that difference in a vape. The atomizer and its settings combined with your technique has a big influence and in some cases will override the coil choice. The only difference that remains is that one is being overridden more than the other. In other cases, the vape would be more similar if the power was set different between the 2 coils, to compensate for the size difference of the coils. One making up to 50% more vapor, in that case, would be somewhat noticable. Leaving the power the same could result in the smaller coil burning, very noticable, or the larger one underpowered with considerable ramp-up, noticable.

Good info my friend and honestly it's a good idea to know this info, and to the OP, the only way to really see and feel any of these changes is to experiment. It takes time but eventually you will find your sweet spot. For me personally, I vape a rotation of 6 different mods throughout the day, all with different juices , I have a couple rta's set up around .6 ohms, a couple at .9 ohms, one at 1.1 and one at 1.4 ohms. Yes the lower ohm coils are a thicker wire and I vape them all at around 23 watts. For me, they all seem pretty close in vapor and flavor.

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[Cheallaigh]

the issue is the OP is actually not using a regulated mod ( justfog q16 )... he's using sorta-mech with a constant voltage setup and some safeties according to its specs... so it is likely he will notice the difference between the two different ohms.

 

[TheLawbird]

If that is the case then OP shouldnt ever have to experience the situation that he presented. Unless he is overcharging batteries and and using them past the point that they need to be recharged.
I am not saying that his 4.2 or 3.4 Volts is over/under charging because i don't know what kind of batteries he is using

As it is though, your vaping experience is going to be dictated by how quicly your coils gets to temp, and how how hot it actually gets. Watts is absolutely not a measurement of heat, it is just a measurement of power passing through the coil. And the type and size/gauge of that coil is what determines how quickly and what temps that coil acheives at different wattages

 

[vapdivrr]

the issue is the OP is actually not using a regulated mod ( justfog q16 )... he's using sorta-mech with a constant voltage setup and some safeties according to its specs... so it is likely he will notice the difference between the two different ohms.

I would agree more if using a mech maybe, but it's been so long since using one

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