model number of the furnace?
The motor is limited to just under the synchronous rpm - so 1200 synchronous, rated speed 1075 rpm and unlikely to ever exceed 1100 rpm.
So running the motor under-loaded doesn't increase the speed much at all.
Using a lower speed tap weakens the motor but for it to slow down below normal high speed, the load has to exceed the strength of the motor on a specific speed tap.
So if your tech wired cooling for high and heating for medium high, probably running at same rpm in heating and cooling mode - resulting in more air volume in heating mode.
Over-sized motors use more electricity and some say have a shorter lifespan too. The speed range is more limited -> normally 4 speeds and medium low could be equivalent to high speed of the old motor.
The motor is limited to just under the synchronous rpm - so 1200 synchronous, rated speed 1075 rpm and unlikely to ever exceed 1100 rpm.
So running the motor under-loaded doesn't increase the speed much at all.
Using a lower speed tap weakens the motor but for it to slow down below normal high speed, the load has to exceed the strength of the motor on a specific speed tap.
So if your tech wired cooling for high and heating for medium high, probably running at same rpm in heating and cooling mode - resulting in more air volume in heating mode.
Over-sized motors use more electricity and some say have a shorter lifespan too. The speed range is more limited -> normally 4 speeds and medium low could be equivalent to high speed of the old motor.