A large air handling unit (AHU) in the building had a leaking preheat valve.  As a result, the discharge air temperature from the preheat coil was over 100F, as seen in Figure 1.  Consequently, the cooling coil valve was opening to provide mechanical cooling for the final AHU discharge temperature to meet setpoint. 

This fault was not detected on site because the final discharge from the AHU was meeting setpoint due to mechanical cooling.  However, this was detected with Analytika algorithms, and Cimetrics provided specific root cause analysis to direct facilities personnel to the leaking coil valve.

Figure 1: Leaking preheat coil valve

Solution

Cimetrics worked with GHPF facilities personnel to replace the faulty equipment, paid for from their O&M budget.

Annual energy savings achieved: $55,027

Annual carbon emissions reduction: 264 metric tons