|Kwinten Koëter Venture-Agent, Netherlands—Utrecht aka Quentin Coldwater|
I basically factor in a roughly one-minute time lapse after each fight: coming down from the adrenaline rush (it is a scary situation, after all), cleaning weapons/armour, and using wands to restore HP (maybe more on high level, but then durations go up as well).
If they're not looting the room/enemies, I'd give them two fights, maybe three if the fights are very close after each other. Remember, in the fiction they also have to travel and discuss tactics, that also takes more time than you'd think. And in-game, there's still things like room descriptions and stuff that take time to process.
Looting a room would also be one or two minutes, depending on how much they find and how many magical items they need to identify. If they find a logbook with a specific handout, the adventure presumes they magically find that one interesting page, but in the fiction it might take anywhere between ten and thirty minutes, depending on how much information they need to sift through. Maybe even more.