Do SS coils require more power than Kanthal coils?

[UncLeJunkLe]

I never used anything but Kanthal and Nichrome wire to build my coils.

All things being 100% equal (wire gauge, coil type, coil diameter, ohms, etc) do SS coils require more power to run to get the same vapor as the exact same coil/resistance made from Kanthal or Nichrome wire?

 

[Punk In Drublic]

All things cannot be equal, it’s impossible. For the same gauge and amount of wraps, SS316L will always be lower in resistance, have a higher Specific Heat Capacity and higher mass. The physics behind the later 2 dictate that SS316L will require more power to heat the coil to the same temperature within the same duration as Kanthal. That said, depending on the dimensions of the coil, the difference maybe subtle and unnoticeable.

 

[UncLeJunkLe]

All things cannot be equal, it’s impossible. For the same gauge and amount of wraps, SS316L will always be lower in resistance, have a higher Specific Heat Capacity and higher mass. The physics behind the later 2 dictate that SS316L will require more power to heat the coil to the same temperature within the same duration as Kanthal. That said, depending on the dimensions of the coil, the difference maybe subtle and unnoticeable.

Right, I thought that would be obvious. What I meant was, all things being equal that can be equal to get to the same resistance and coil type/diameter, etc. Things that would be equal...

• Wire Gauge
• Coil type
• Coil's inner diameter
• Leg length
  
• Resistance of the coil

I understand that more wraps would be needed with SS to get to the same resistance, but all other things being equal.

Seems I have to run an SS coil at almost 2x the wattage to get the same vapor/experience as Kanthal/Nichrome. Wondering if this is normal or not.

 

[Punk In Drublic]

Right, I thought that would be obvious. What I meant was, all things being equal that can be equal to get to the same resistance and coil type/diameter, etc. Things that would be equal...

• Wire Gauge
• Coil type
• Coil's inner diameter
• Leg length
  
• Resistance of the coil

I understand that more wraps would be needed with SS to get to the same resistance, but all other things being equal.

Seems I have to run an SS coil at almost 2x the wattage to get the same vapor/experience as Kanthal/Nichrome. Wondering if this is normal or not.

Wire gauge, coil type, inner diameter and leg length can all be the same. I referred to that as dimensions. Resistance can not be the same if we were to match the former criteria.

For the same dimension wire, SS316L is lower in resistance, higher Specific Heat Capacity and higher mass than Kanthal. If we were to match resistance, SS316L would be significantly higher in mass and will require a significant amount of power to heat to the same temperature within the same duration.

If we were to match mass, the higher Specific Heat Capacity of SS316L would still require more power to reach the same temperature within the same duration.

 

[Punk In Drublic]

Also note that SS316L has a vastly higher TCR (temperature coefficient of resistance) than Kanthal. As it heats, its resistance rises. With a fixed voltage source, this means the output in power will diminish in accordance with the rise in resistance. A 0.2 ohm coil with a 4 volt source could begin at 80 watts, but as resistance increases with heat, could end up being a 0.35 ohm coil which would yield a 45 watt output.

With a regulated device, the device has to adjust the voltage in order to maintain your prescribed wattage. Any latency in this adjustment could also affect how quickly the coil heats.

 

[ChelsB]

Also note that SS316L has a vastly higher TCR (temperature coefficient of resistance) than Kanthal. As it heats, its resistance rises. With a fixed voltage source, this means the output in power will diminish in accordance with the rise in resistance. A 0.2 ohm coil with a 4 volt source could begin at 80 watts, but as resistance increases with heat, could end up being a 0.35 ohm coil which would yield a 45 watt output.

With a regulated device, the device has to adjust the voltage in order to maintain your prescribed wattage. Any latency in this adjustment could also affect how quickly the coil heats.

Great explanation!

 

[DaveP]

Good article on wire types, uses, and how they relate in resistance and temperature coefficience.

https://www.gearbest.com/blog/how-t...-vs-stainless-steel-vs-nichrome-vape-wire-776

 

[dripster]

If the metal type is different, logically it follows that the various properties of the metal type will also be different (e.g., resistance, specific heat capacity, density i.e. mass divided by volume, and heat transfer rate). But for reasons that should be equally obvious, to be able to examine these differences everything else that isn't the metal type nor is among its properties must be kept the same, i.e., the thickness of the wire, the total length of the wire that also includes the length of the legs, the number of wraps, and the diameter of the coil all need to be identical. Changing the thickness and/or length etc. to compensate for any difference that occurs as a direct result from changing the metal type would technically be called cheating. Anyone who disagrees with this trivial fact can not be helped (pun intended).

That said, Kanthal A1 requires more power than SS 316L if you want the rampup speed of the coil to be identical. But if you are talking about the specific part of vapor production that occurs after the rampup is finished, i.e. when surface temperature is kept invariable, then no, the metal type has no impact on the amount of power required for that, due to the First Law Of Thermodynamics.