What does AHU-X09 mean?
The supply fan is running above its minimum speed but the cooling load is near zero.
Why does it matter?
Fan power is cubic in speed — riding a VFD at 70% with no load wastes 3× more than necessary. This is a top-three air-side waste on overlooked AHUs.
What should you do?
Check whether the DSP setpoint is too high (fan ramps to maintain pressure with no demand), whether minimum-OA logic is forcing flow, or whether the BMS lost its trim-and-reset routine and the fan is at constant speed.
How Energy Agent prices a finding
Written by Pelorus Engineering · Brent Waluzak, P.E. (FL), President, Pelorus EngineeringLast updated