RTA dual coil question.

[crimsonsoda]

I tried my friend's orchid today. All I can say is ''wow''! I currently build single coils on my Squape and my Kayfun. My friend told me that I would not be able to fire the orchid at 1.2 Ohms on my Lavatube or my Istick, only on my Hana DNA 30 clone. Just out of curiosity, why? All my devices fired the Aerotank with the Kanger dual coils at 1.2 Ohms... I understand that the amp limit on those two devices is the limiting factor, but why the Kangertech dual coils fired then?

 

[Double Helix]

I'm unfamiliar with the lavatube, but with some specs I pulled off Google the highest voltage you'd be able to fire it at would be 3.6 volts with that build. The device does support all the way down to 3 volts. It's not that the device won't fire it but the fact that 3.6 volts is a low setting that is undesirable for most. With that said I wouldn't be pushing a device right at it's amp limit.

As for why that build wouldn't work with the iStick, I have no idea why he said that. It fits well within it's specs.

I don't really see a problem though. Just build a coil with a higher resistance if your device doesn't support it.

 

[crimsonsoda]

Thanks. I will order an Orchid and give it a try then.

 

[PapaSloth]

You can fit dual coils on your Kayfun as well. It's a little tight, but quite manageable. I do this myself. Here's a picture to get you started (not my build, but the same thing I do):

 

[Smann245]

I doubt your friend used the same super thin wire that a pre built coil head in a clearomizer uses. Stating only the ohms is pointless. 1.5 ohms of 34g is not even close to the same thing as 1.5 ohms of 22g wire. Heating more metal requires more power even if the resistance is the same. A dual coil rebuildable can be used with a 20w device, but you won't be coming anywhere near the atomizers potential.

 

[VHRB2014]

You can fit dual coils on your Kayfun as well. It's a little tight, but quite manageable. I do this myself. Here's a picture to get you started (not my build, but the same thing I do):

I did`nt have any love for my KF until I did a double barrel, then WOW, super vapor and flavor.
Than my wife tasted it, and I moved on to a Fogger, LOL.

 

[PapaSloth]

Heating more metal requires more power even if the resistance is the same.

Not exactly true. It just takes longer for more metal to reach the limit temperature, and longer for it to cool off when the power is cut. The actual Wattage is the same, so the total amount of heat produced per unit time, on average, is the same.

 

[Smann245]

Not exactly true. It just takes longer for more metal to reach the limit temperature, and longer for it to cool off when the power is cut. The actual Wattage is the same, so the total amount of heat produced per unit time, on average, is the same.

Bologna. One thermal unit of heat applied to a cup of water and one thermal unit of heat applied to a gallon of water cause the cup of water and the gallon of water to end up being different temperatures.

 

[PapaSloth]

Bologna. One thermal unit of heat applied to a cup of water and one thermal unit of heat applied to a gallon of water cause the cup of water and the gallon of water to end up being different temperatures.

You're right, I was wrong. The larger coil will spread the power over a larger surface area of juice, but at a lower temperature. You should get less vapor per unit area, but over a larger number of unit areas. The total vapor production should be comparable.

Edit: On second thought, I might not have been wrong. Both the small coil and large coil are going to be limited by the vaporization temperature of the juice and will level out at the same temperature. From that point on, the excess power will be converted to vapor. I still think roughly the same amount of vapor will be produced though, just less vapor per unit area but a larger number of unit areas for the large coil.

 

[dchemist]

Bologna. One thermal unit of heat applied to a cup of water and one thermal unit of heat applied to a gallon of water cause the cup of water and the gallon of water to end up being different temperatures.

Only in the same time frame. With time excluded the same amount of heat energy applied to a cup versus a gallon of water will eventually lead to the cup and the gallon being the same temperature (assuming you can somehow keep the steam from escaping and also not adding any heat back to the water). Once the heat energy is removed, both will dissipate the heat back to the environment until they both reach equilibrium. In this case the cup, with less mass, will reach equilibrium faster than the gallon.

 

[edyle]

Not exactly true. It just takes longer for more metal to reach the limit temperature, and longer for it to cool off when the power is cut. The actual Wattage is the same, so the total amount of heat produced per unit time, on average, is the same.

The same voltage applied to the same ohms will produce the same watts, correct;
however with thicker wire of the same ohms there is more surface area for the heat to dissipate.
Hence the thicker wire doesn't get to the same temperature.
Just imagine a real big coil made with obnoxiously thick wire (like car battery size wire) coming out at standard 2 ohms; it doesn't matter how long you put 4 volts on it, it won't even get warm. Probably be a foot long too.

 

[PapaSloth]

Only in the same time frame. With time excluded the same amount of heat energy applied to a cup versus a gallon of water will eventually lead to the cup and the gallon being the same temperature (assuming you can somehow keep the steam from escaping and also not adding any heat back to the water). Once the heat energy is removed, both will dissipate the heat back to the environment until they both reach equilibrium. In this case the cup, with less mass, will reach equilibrium faster than the gallon.

Good point, I edited my response

 

[sketchness]

SO while this thread is drifting sideways..... Make sure you buy 30 or 32 gauge kanthal to build on your orchid with the istick. It will heat up much faster and the vape will be more dense. It will still work with the lower gauges if you reach the minimum resistance limit but it will heat very slowly and lack vapor production. 30&32 are much easier to work with if you torch them first, then wrap your coils. and it would probably be best to use 32 gauge.

 

[dchemist]

Good point, I edited my response

You were correct strictly speaking in joules (amount of energy required to raise 1 g of water by 1 degree C) however!

 

[PapaSloth]

The same voltage applied to the same ohms will produce the same watts, correct;
however with thicker wire of the same ohms there is more surface area for the heat to dissipate.
Hence the thicker wire doesn't get to the same temperature.
Just imagine a real big coil made with obnoxiously thick wire (like car battery size wire) coming out at standard 2 ohms; it doesn't matter how long you put 4 volts on it, it won't even get warm. Probably be a foot long too.

This is not correct. Imagine a sauce pan and a big pot of water both on a gas stove with burners set to high. Both pots will eventually reach 212F and the water will start boiling. It will take less time for the sauce pan to reach 212F than the pot, but both will get there eventually. Here's the interesting part: both will stay right there around 212F until all the water is boiled off. They will even release roughly the same amount of steam, because the steam produced is a function of the amount of power the burner is delivering to the pot or pan (ignore for the sake of argument that the saucepan has a smaller diameter than the pot, and some of the heat from the gas burner goes off to the side).

That's what's happening to your coils when they're wicked and the wicks are wet with juice. They reach the vaporization temperature of the juice, but don't go any higher until all the juice is burned off (which should never happen. Dry hits suck).

 

[PapaSloth]

SO while this thread is drifting sideways..... Make sure you buy 30 or 32 gauge kanthal to build on your orchid with the istick. It will heat up much faster and the vape will be more dense. It will still work with the lower gauges if you reach the minimum resistance limit but it will heat very slowly and lack vapor production. 30&32 are much easier to work with if you torch them first, then wrap your coils. and it would probably be best to use 32 gauge.

Just as a point of interest - I'm running dual coils with 4 wraps each on a 1/8" diameter coil, made of 4 strands of twisted 30 gauge Kanthal on my Big Buddhas. That's the equivalent resistance and thickness of 24 gauge wire. Net for the build is 0.3 Ohms. It's a LOT of wire. It takes about 4 seconds for the vapor to start coming, but when it gets there, it produces A LOT of cloud. So, it's not entirely correct to say it lacks vapor production. It does heat somewhat slowly (you might consider it very slowly, it doesn't bother me particularly).

 

[sketchness]

Just as a point of interest - I'm running dual coils with 4 wraps each on a 1/8" diameter coil, made of 4 strands of twisted 30 gauge Kanthal on my Big Buddhas. That's the equivalent resistance and thickness of 24 gauge wire. Net for the build is 0.3 Ohms. It's a LOT of wire. It takes about 4 seconds for the vapor to start coming, but when it gets there, it produces A LOT of cloud. So, it's not entirely correct to say it lacks vapor production. It does heat somewhat slowly (you might consider it very slowly, it doesn't bother me particularly).

I understand what you are saying. But for the purposes of the question the OP posed this information is irrelevant. The fact that twisted 30 gauge Nichrome coils hit like a beast on my sigelei won't be of much help.

 

[PapaSloth]

I understand what you are saying. But for the purposes of the question the OP posed this information is irrelevant. The fact that twisted 30 gauge Nichrome coils hit like a beast on my sigelei won't be of much help.

Yeah, I'm using a mech mod, so 4.2V on a fresh battery. It works great.