Objective/Method/Outcome
Objective: Determines if cold deck temperature control is at fault for more than the acceptable time.
Method: Compares the recorded cold deck temperature to the sum of setpoint and temperature threshold to determine if the recorded temperature is under the acceptable range and if it is, the 5 minutes score is calculated by multiplying the temperature error and the hours of fault. This is used to estimate the cost of fault per day, and project the potential savings.
Outcome: Triggers an insight when the insight is less than the acceptable threshold and the control error severity found and the potential saving from fixing this error found.
Description
Determine the error severity of a cold deck temperature control system in degree*hours.
This rule is part of the CopperTree Standard rule-set.
Calculate the severity metric based on the absolute difference between the cold deck temperature (CDT) and the CDT setpoint deadband during scheduled hours.
Default Priority
Low
Diagnosis
- Issue with control loop. Review and modify controller tuning parameters.
- Automatic setpoint control has been overridden. Revert setpoint back to automatic control.
- Heating water not available. Verify boiler plant operation.
- Input sensor(s) faulty or mis calibrated. Verify input sensor(s) operation.
- Primary air not available. Verify Air Handling Unit operation.
Message
Cold deck temperature has deviated from setpoint at a higher severity than specified.
Rule Template
Insight Type: Integrity KPI
Trigger Type: Active High
Logic
Inputs
| Input | Unit | Tags | Description |
|---|---|---|---|
| Cold Deck Temperature | ° | Cold Deck – DAT | The recorded cold deck temperature |
| Cold Deck Temperature Setpoint | ° | Cold Deck – DAT Setpoint | The setpoint of the cold deck temperature |
| Status | Discharge Air Fan Status, Discharge Air Fan Command | The status of the DAF | |
| Const. – Temperature Threshold | ° | The minimum temperature that can trigger an insight | |
| Const. – Acceptable Weekly Threshold | °*hr | The weekly threshold of acceptable hours of fault | |
| Cost per Degree*Hour | $ | The cost per hour of fault | |
| Days of operation annually | The estimated yearly days of operation |
Notes
Default Thresholds:
- Temperature Deadband: 1.5°
- Acceptable Weekly Degree*Hours: 40
