I am an apprentice doing installs and I recently installed a Lennox G40 gas furnace with air conditioning at my mothers house. I am trying to figure out how to bump up the fan speed. On the board, there is sort of a dip switch that reads 60 80 120 160. Is that the CFM switch for fan speed or is that the defrost timer for a heat pump? Install manual is not that helpfull. Want to get advise first before I mess with it so I dont fry something on the bored. Any info would be helpfull.