There has been talk about what compounds can be created when eliquid is vaporized at high temperature. Dr. F's next study should produce some data and analysis to help clear the air. There is a common misconception that higher wattage means hotter coil temperature. This is simply not the case. It is a multivariant phenomenon. There are six main variables which are also dependent on other variables.
1) Power delivered to the coil which depends on the voltage drop across the coil and current through the coil (replace either voltage drop or current with resistance of the coil if you please, it's just harder to measure the coil resistance when current is flowing)
2) Mass of the coil which is dependent upon the material density, length, and gauge.
3) Evapoative cooling dependent on so many things but mainly surface area in contact with the wick, the current (ml/s not A) of the eliquid through the wick, the composition of the eliquid (pg/vg ratio), and the current of air flow over the coil.
4) Convection into and inside of the atomizer mainly dependent on draw pressure & velocity, air hole diameter & shape, and chamber size & shape.
5) Specific Heat of the coil material.
6) Fire time. How long the coil is passing current.
If we assume A1 Kanthal, 2 is simplified and 5 is eliminated as a variable. In my personal experience, I've found it way easier to over heat the coil on an iClear at 7W than a rebuildable dripper at 60W. Low mass, small surface area, slow wicking, low airflow current, and very small chamber all contributed to a higher coil temperature at significantly lower power.
Any geeks out there want to help me try to model this beast? We'd be entering nonlinear, nonseperable, differential equation land.
1) Power delivered to the coil which depends on the voltage drop across the coil and current through the coil (replace either voltage drop or current with resistance of the coil if you please, it's just harder to measure the coil resistance when current is flowing)
2) Mass of the coil which is dependent upon the material density, length, and gauge.
3) Evapoative cooling dependent on so many things but mainly surface area in contact with the wick, the current (ml/s not A) of the eliquid through the wick, the composition of the eliquid (pg/vg ratio), and the current of air flow over the coil.
4) Convection into and inside of the atomizer mainly dependent on draw pressure & velocity, air hole diameter & shape, and chamber size & shape.
5) Specific Heat of the coil material.
6) Fire time. How long the coil is passing current.
If we assume A1 Kanthal, 2 is simplified and 5 is eliminated as a variable. In my personal experience, I've found it way easier to over heat the coil on an iClear at 7W than a rebuildable dripper at 60W. Low mass, small surface area, slow wicking, low airflow current, and very small chamber all contributed to a higher coil temperature at significantly lower power.
Any geeks out there want to help me try to model this beast? We'd be entering nonlinear, nonseperable, differential equation land.
