Applicable Systems
- Primary: BLR
Objective/Method/Outcome
- Objective: Determine boiler temperature performance score
- Method: Analyze the daily performance metric based on the total time the HWST is within the deadband while the unit is on.
- Outcome: A KPI score is generated on a daily basis while a ‘Bad Score’ insight is produced if the weekly KPI score is lower than a threshold (default 60%).
Logic
- Input normalized hot water supply temperature and its corresponding temperature set points.
- With a temperature setpoint deadband constant, check if the deviation is out of acceptable range.
- If threshold is exceeded and the building is active, pass the hourly score.
- Aggregate samples into a daily and weekly score; generate the daily KPI score in a CTL.
- If weekly score exceeds acceptable weekly threshold, generate an insight. Note: the user must change the trigger block to “Insight – Bad Score”.
while(occ == 1)
{
if( |HWST - HWST SP| > Deadband Const. )
{
Award performance KPI score 0%
}
else
{
Award performance KPI score 100%
}
average performance KPI score daily
average performance KPI score weekly
}
Determine boiler temperature performance KPI score
Description / Method
Determine the performance index of a hot water supply temperature (HWST) control system using the amount of time the hot water supply temp is within the deadband (SP ± 3)while the unit is on. {BLR | heatexchanger}
Diagnosis / Recommended Action
- Issue with control loop. Review and modify controller tuning parameters.
- Heating water not available. Verify boiler plant operation.
- Automatic setpoint control has been overridden. Revert setpoint back to automatic control.
- Input sensor(s) faulty or miscalibrated. Verify input sensor(s) operation.
Message
The boiler’s hot water supply temperature KPI score is below 60% for the week. Review control loop tuning parameters.
Notes
This rule will not generate an insight unless the user changes the Trigger Block to “Insight – Bad Score”.
This rule is designed for °C inputs by default.Default Constants:
- Const. – Acceptable Weekly Score [%]: 60
- Const. – Hot Water Supply Temperature Deadband [°C]: 3
- (Recommended default deadband for Fahrenheit is 5 °F)
CTL Generated:
- HWST Performance KPI
Rule Template Type
- Insight Type: Integrity KPI
- Trigger Type: Active High
Default Priority
Low
Inputs
| Inputs | Units | Default Value | Tags | Description |
|---|---|---|---|---|
| Hot Water Supply Temperature | °C | sensor, leaving, hot, water, temp | Hot water supply temperature from boiler | |
| Hot Water Supply Temperature Setpoint | °C | sp, leaving, hot, water, temp | Hot water supply temperature set point | |
| Boiler Status | cmd|status | Building occupancy | ||
| Const. – Hot Water Supply Temperature Deadband | °C | 3 | The acceptable temperature change of the unit from setpoint | |
| Const. – Acceptable Weekly Score | % | 60 | The lowest acceptable weekly KPI score |
Output Calculated Trend Logs
| Output CTL | Units | Description |
|---|---|---|
| HWST Performance KPI | % | Score representing the amount of time the hot water supply temperature is within deadband, as a percentage |
