I've noticed that there seems to be a disconnect between the input and output for the time and opening fraction and of a wall vent if the engineering length units are selected as something other than meters. If you want a door to open at 10 minutes, and the length is set to feet, it'll open the door at about 55 seconds with a fraction of 0.3048 in the output files. If you enter the time and fraction when the units are feet, and then change it to meters, it'll change the time/fraction as well. There's some screenshots below showing this

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