On residential applications I am still on the learning curve in regard to variable speed blowers, but my understanding is that static pressure most often determines ECM motor speed. The electronic equipment monitors the torque and speed of the motor, which is affected by the static pressure of the equipment and ductwork.
Originally posted by bornriding
Thanks for very good explanation. Further questions please as I have never had to deal with ecm motors.
What factor determines the speed of the motor - what factors involved?
Also are the ecm motors variable over the entire range ( from 0 to full speed ) or are they more like a two or three speed motor?
And yes, I was concerned about the coil freezing if the blower speed got too low, if the refrigeration wasn't reduced.
[Edited by bornriding on 02-11-2005 at 05:27 PM]