Just wondering if anyone has replaced their conventional furnace /
HVAC fan motor (PSC, single phase, etc) with one of the new ECM motors
to realize a reduction in your electricity bill.

Does anyone know what the "over-the-counter" cost is of these motors?

Also, do ECM motors generate electrical or RF noise that is either
radiated by the motor or fed back into the household wiring, thereby
messing up AM radio reception?