I know it all depends on your model of burner, weather, etc... But what is your average boil off rate for a 60 minute boil? Brewers with propane burners answer ONLY please. I am about to brew my first propane burner batch and am trying to get a good idea. The burner I got (for free) is a no name, smaller looking model...
You have already won half the boil-off battle by realizing it's a volume per time unit and not a percentage per time unit. I voted 1.25, as my average calculated long ago was 1.24.
About 1.75 , best guess. Never actually measured accurately, but this has been pretty true of my last couple.
About 1 gallon (7% of my preboil volume) per hour, when my preboil volume is in the 13.5 - 14 gallon range.