Greenheck Melink IH3 Operations - Manual (Page 18)

It should be noted that fan energy is proportional to the square of fan speed. Thus a fan running
at 90% of maximum speed uses 81% (0.90 * 0.90) for the energy as the fan running at 100% speed. A
fan running at 50% speed uses 25% of the energy. Thus, most of the energy savings come from
trimming the high end of the fan speed profile. It is more important to shave off speed at the high end
by properly calibrating temperature span than it is to shave off speed at the low end with the minimum
speed.