EEM Motor vs ECM Motor for Goodman

[Polibio]

Hi everyone,
Can anyone explain to me the difference between the two? Goodman offers them in some of their air handler models: AEPF is a V/S with ECM motor, while the ASPF is multispeed w/ EEM motor. When paired to the SSZ140361A*, the ARI performance is exactly the same: ARI#3068848, and ARI#3068856.
The EMM motor is supposed to be “energy efficient”. In what way, though? Price difference is significant.

Thank you.

[BaldLoonie]

The EEM is must be GE's X13 motor. It uses about the same electricity as a variable speed motor but without other benefits so is less money to buy. It works like a standard motor meaning any restriction in the ducts means lowered airflow. The variable speed motors can sense duct changes and adjust their speed to try to maintain the desired airflow. The X13 like a standard motor can't do that so as a filter gets dirty, for example, airflow goes down. Not sure how Goodman does it but in 1 brand we use, the X13 will go to 1/2 speed for constant fan, like a variable speed motor does.

The X13 is a nice stepup from a standard motor saving energy without the higher initial cost of VS. If budget allows, the VS is still most desirable.

[beenthere]

What he said.