Determine supply air pressure performance KPI score

Applicable Systems

• Primary: AHU

Objective/Method/Outcome

• Objective: Determine supply air pressure performance KPI score.

• Method: Determine the performance index of a supply pressure control system using the amount of time the supply pressure is within the deadband while unit is on.

• Outcome: A performance KPI CTL is generated on a daily basis while there are no insights. However, a user can change the trigger block to “Insight – Bad Score”, and an insight will be generated if the weekly score is below 60%.

Logic

• Input the normalized supply static pressure with its correlating set point.
• With an input percent threshold of 15, deviation exceeding the threshold is scored hourly when the building has an active occupancy.
• The hourly score is then aggregated to produce a weekly KPI score.
• If desired (by changing trigger block to “Insight Trigger – Bad Score”) an insight is generated if the weekly score is below 60%

while(occ == 1)
   {
   if( |SSP - SP|  > 15% SP)
         {
         Award performance KPI score 0%
         }
   else
         {
         Award performance KPI score 100%
         }
   average performance KPI score daily
   average performance KPI score weekly
   }

Description / Method

Determine the performance index of a supply pressure control system using the amount of time the supply pressure is within the deadband while unit is on. {AHU}

Diagnosis / Recommended Action

1. Issue with control loop. Review and modify controller tuning parameters.
2. Automatic setpoint control may have been overridden. Review pressure setpoint control.
3. Input sensor(s) faulty or miscalibrated. Verify input sensor(s) operation.
4. Primary air not available. Verify Air Handling Unit operation.

Message

AHU’s Supply Static Pressure KPI score was less than 60% for the week. Review control loop tuning.

Notes

This rule will not generate an insight unless the user changes the Trigger Block to “Insight – Bad Score”.Default Constants:

• Const. – Static Pressure Deadband [%]: 15
• Const. – Acceptable Weekly Score [%]: 60

CTL generated:

• SSP Performance KPI

Rule Template Type

• Insight Type: Integrity KPI
• Trigger Type: Active High (Typically no trigger)

Default Priority

Low

Inputs

Inputs	Units	Default Value	Tags	Description
Supply Static Pressure			sensor, discharge, air, pressure	Supply static pressure system behaviour data
Supply Static Pressure Set Point			sp, discharge, air, pressure	Supply static pressure system set points
Fan Status			occupied	Building occupancy
Const. – Static Pressure Deadband	%	15		Percent threshold of pressure deviations
Const. – Acceptable Weekly Score	%	60		Lowest KPI score allowed before generating an insight

Output Calculated Trend Logs

Output CTL	Units	Description
SSP Performance KPI	%	Score representing the amount of time the supply air pressure is within deadband, as a percentage