Wire gauge versus power.

[Mike H.]

I typically build 1.7 1.8ohm coils using 30g kanthal in my standard evod tanks....On my new mvp 20w ive found i like around 8 to 9 watts with them..They're usually a micro coil with 8 wraps on a 1.8mm i.d.

So now i wanted to see what a much lower ohm coil did for me and come up with a 1.3 ohm as registered on the mvp ohm meter function....I still only found needing .5 more for a total of 9.0 watts max to give me the vape i had with 1.8 ohm...Maybe its just me but shouldnt it be much higher for a 1.3 ohm?...if max is 20w for a 1.0 ohm coil why is my vape so low on the wattage scale at 1.3ohm ?...Is it the small gauge wire im using?

Im still so far from using 20 watts on my mvp and so close to its limit....with 5 wraps it registers 1.0 ohm which is what innokin advertises as max ohms for 20watts...Ive seen some reports of .8 ohm being used and it still fire...i havent tried the 1.0 ohm as of yet but im tempted just to see how much higher i would need to go to get my personal sweet spot again...I just wouldnt understand needing only 10 maybe 11 watts and max out the ohm capabilities of the device.

Do i have something mixed up here or not understanding something correctly?

Thanks in advance for any help.

 

[BoomStick]

If you keep the wire gauge the same, to reduce resistance you have to use less wire. That means less power is required to make the coil reach the same temperature. It also means less wire in contact with wick/juice which means less atomization occurs.
It's not all about power, it's also about what your applying the power to. Coil geometry and the amount of metal being heated need to be considered along with chamber size, airflow capacity, personal performance preferences, etc. Focusing on voltage and resistance only ignores a great many factors that affect the performance of an atty/mod combo.
5 wraps of 30g wire is not providing much coil surface area. You'll get better performance using more wire (more wraps). If you really want to take it to the next level, buy a proper rba. If you're already building and wicking coils and you have a 20watt mod, get a nice single coil rba and see what you're missing. A kayfun and a 20w mod are a great combo.

 

[nightshard]

The larger the surface area, the better the performance, but on the other hand the bigger the mass, the longer the coil retains head and the longer it takes for it to heat up (while higher power diminishes this negative effect).

 

[Mike H.]

Thanks all...so its not that you need more power to fire a lower ohm but more so to have more wraps with a larger gauge wire for surface area, then needing the added power to fire it with..Think i understand it now.

 

[Mommay]

Look at the info on www.steam-engine.com. You can see how much voltage and wattage is required for whatever ohm you choose. Also, you can look on another tab for your mods median resistance and what the sweet spot is (the resistance that will give you the most range to make manual adjustments, etc). Other tabs for other info.

From Steam-Engine:
A 1.8 coil pulls 1.9 amps and/or needs 6.81 watts
where a 1.0 coil will pull 3.5 amps and/or needs almost twice the power at 12.25 watts

The electrical stuff still confuses me. I'm easily confused (LOL), but I use this calculator often.

 

[Mike H.]

Thats where i was confused...i was thinking because any gauge coil was built to a 1.0 as opposed to a 1.8 ohm that i would need alot more power but didnt find that with my difference between 1.8 and 1.3 ohm comparison with 30g wire

Im understanding it now as, to build a better coil i need more surface area which i would get with a higer gauge wire as i would need more wraps to acheive the same ohm rating...so if im 1.8 ohm with 9 wraps on 30 g i may need 11 or 12 wraps with 28g to get the same ohm reading but needing more power to fire it quickly...and get better performance in general.

 

[nightshard]

Thanks all...so its not that you need more power to fire a lower ohm but more so to have more wraps with a larger gauge wire for surface area, then needing the added power to fire it with..Think i understand it now.

In the past, people that used mechs and wanted more power aimed for lower resistance, since in that case lower resistance directly translates into more power.
With a high powered regulated mod, the resistance is no longer a major factor and with some mods aiming too low or too high can even prevent the mod from reaching it's max settings.
Aiming at an optimal coil in terms of surface and mass according to the power supplied, is what matters.

 

[BoomStick]

Look at the info on www.steam-engine.com. You can see how much voltage and wattage is required for whatever ohm you choose. Also, you can look on another tab for your mods median resistance and what the sweet spot is (the resistance that will give you the most range to make manual adjustments, etc). Other tabs for other info.

From Steam-Engine:
A 1.8 coil pulls 1.9 amps and/or needs 6.81 watts
where a 1.0 coil will pull 3.5 amps and/or needs almost twice the power at 12.25 watts

The electrical stuff still confuses me. I'm easily confused (LOL), but I use this calculator often.

This is another example of ignoring important factors. A single 32g coil measuring 1ohm and quad 20g coils measuring 1ohm have completely different power requirements to reach the same temperature.

 

[Mike H.]

In the past, people that used mechs and wanted more power aimed for lower resistance, since in that case lower resistance directly translates into more power.
With a high powered regulated mod, the resistance is no longer a major factor and with some mods aiming too low or too high can even prevent the mod from reaching it's max settings.
Aiming at an optimal coil in terms of surface and mass according to the power supplied, is what matters.

I cant see trying anything thicker than the 30g wire for my evods and protanks as i think juice would seep through the insulators...so a new tank is on the list...maybe a kayfun v4 clone and a nice 1.2ohm 28g micro coil...off to work ..back later tonight...thanks again everyone

 

[BoomStick]

Building a kayfun is the same as anything else you're gonna run with a variable device. The diameter and length of the coil along with what temp it reaches is more important than what it's resistance measurement is. The goal is to have a certain amount of contact area between heating element and juice as well as making the heating element reach a certain temperature. After finding just the right coil geometry for my kayfun (diameter and wraps) that provided the performance I want, it happened to turn out to be a 2.1ohm coil. Since I have a variable device I can apply whatever watts I want to that coil. (Within my mod's limits of course.) If my preferred coil geometry had turned out to be 1.5ohms instead, who the hell cares? Don't worry about building to a target resistance. Build to a target coil size and apply the power necessary to make it reach the temp you want.

 

[Mommay]

This is another example of ignoring important factors. A single 32g coil measuring 1ohm and quad 20g coils measuring 1ohm have completely different power requirements to reach the same temperature.

Yea, but the OP was talking about an Evod clearo on a 20 watt device- -- nothing ignored--

 

[BoomStick]

Ok. A single 32g coil and a single 20g coil, both with the same resistance, reach completely different temperatures with the same power applied. What I said still stands. There are important factors still being ignored.

 

[BoomStick]

From Steam-Engine:
A 1.8 coil pulls 1.9 amps and/or needs 6.81 watts
where a 1.0 coil will pull 3.5 amps and/or needs almost twice the power at 12.25 watts

My 2.1ohm coil needs 17watts to achieve the performance I want. How many amps any ohm coil pulls depends on how much voltage is applied. Your statements don't make any sense.

 

[Mike H.]

My 2.1ohm coil needs 17watts to achieve the performance I want. How many amps any ohm coil pulls depends on how much voltage is applied. Your statements don't make any sense.

Safe to assume you use a really heavy gauge wire for the coil?

I just tried a 30g 11 wrap and got 2.3 ohms and found i needed to turn power up more to get the same performance i got with 9 wraps for 1.8 ohm...but im getting better flavor it seems..dont really see a difference in vapor production as i just learned the wider coil can restrict some air flow in a small kanger head like i have.

 

[BoomStick]

28g, 7/64", 9 wrap

 

[BoomStick]

Yep. You add more wire and you need more power to reach the same temp.

There is way more space beside your coil/wick than there is in the little hole in the positive pin. The pin is limiting the air flow, not the coil/wick. Also, if you look at your pic and imagine using more or less wraps, how much is it really gonna change the area of the open area to the sides of the coil/wick? Almost none. Doing the coil and wick like you are, number of wraps has almost no effect on air flow.