I control the boil with my temperature controller, in the area I live, I set the controller to 213.5°f and this gives me a gentle rolling boil, which is my goal, per low oxygen brewing techniques. 214.5 gives me a typical light vigorous boil.
Isn't steam vapor made up of hydrogen and oxygen or does it change when water changes form?
I'm going to fabricate a exhaust system to pull that out of there for DMS issues during the boil I don't believe there are any issues needing exhaust during the match