I've never quite figured out the steam blasts in Volenfell. A Reddit thread
https://www.reddit.com/r/elderscrollsonline/comments/9851m4/noob_here_how_do_you_avoid_volenfells_steam_blast/ seems to say that flipping the lever in front reduces them, after a delay, without specifying what the delay is or whether it's all/just some of the blasts in the corridor. Does anybody have more accurate information or anecdata?
Also, does flipping the lever in back turn them off in all cases, so that you're not troubled when you run back out, or is there an interaction with the setting of the front lever?
Thanks!