The fact that Randell Mills is using "nascent hydrogen" in mix with argon strengthens my suspicion that it's overunity device analogous to Papp's engine rather than dense hydrogen and/or even hydrino device. Maybe the hydrogen/water vapour isn't really necessary in it at all and we get Chernetski plasma device. Both nascent, i.e. atomic hydrogen, both argon have spherically symmetric orbitals, prone to negentropic forbidden electron transitions due to absence of gauss radiation condition.
If You 'll omit Hydrino as posible source of energy, where from You take enrgy exces?
Papp's engine does not exclude hydrino I think.