I have the fan set to run constantly on low. The blower motor is a GE ECM 2.3. Below is some cut & paste info regarding the high efficiency low operation cost for this motor. The motor is supposed to be amazing.
Equipment manufacturers don’t condone poor duct design, but ECM 2.3 motor technology can compensate for some applications if sized incorrectly. However, it is important to be cautious, because increased noise levels, which are uncharacteristic of these motors, may result if the design is overly restrictive.
Overall, ECM 2.3 motors draw the least amount of watts, which makes them the most efficient. On average, they will use approximately 413 watts in cooling mode and only 83 watts (less than a 100-watt light bulb) in continuous fan mode. This combination of performance, reliability, and programmable flexibility makes ECM 2.3 motors an ideal solution for high-SEER or multi-stage system designs. It also has the potential to increase overall cooling system performance by as much as one or more SEER points.
Beyond programmability and efficiency, ECM 2.3 motors offer many other advantages that enhance consumer comfort. These motors are the quietest of the three motor types because they have the ability to ramp up and down slowly, making them ideal for applications where noise is a concern.
Variable-speed motors are also the best choice for constant fan or constant filtering applications because the motor will only run at about one-third of its designed speed, using less power than a 100-watt light bulb and resulting in both noise reduction and energy savings that the consumer will appreciate. The indoor environment will also benefit from better air stratification, ensuring more consistent and precise temperatures.
In addition, ECM 2.3 motors have the ability to deliver customized airflow based on the consumer’s geographic region, making them versatile in humid, arid, or temperate climates. If dehumidification is required, variable-speed motors offer the best solution because of the wide range of speeds, and they are particularly effective when combined with two-stage compressors and a dehumidification control. http://www.achrnews.com/articles/compar ... nologies-1