Delta-T Analysis of Chilled Water System

Objective/Method/Outcome

Objective: Determines if the delta-t of the chilled water system is low for an extended amount of time while is system is running

Method: Calculates the Delta-T of Chilled Water System and groups it into CTL bins of Daily Hours

Outcome: Triggers an Integrity KPI.

Applicable System

Chilled Water System

Description

Calculate Delta-T of a system, then group into CTL Bins of Daily Hours. Generates an insight if Delta-T is low while system is running for extended period of time.

This rule is part of the CopperTree Standard rule-set.

Diagnosis

  1. Ensure temperature sensors are calibrated properly.
  2. Consider load-based control for the CHWS. System could be disabled when there is low demand.

Message

Delta-T is low while system is active.

Rule Template Type

Insight Type: Integrity KPI

Trigger Type: Active High

Default Priority

Medium

Logic

Logic Flow for determining Delta-T for Chilled Water System

Inputs

InputUnitTagsDescription
RWT°C/ °FChilled Water Return TemperatureReturn Water Temperature for Chilled Water System
Chilled Water System Status°C/°FChiller Command, Chilled Water System Enabled, Chiller StatusStatus of Chilled Water System
SWT°C/ °FChilled Water Supply TemperatureSupply Water Temperature
Bin 1 Temperature Threshold°C/ °F
Bin 2 Temperature Threshold°C/ °F
Bin 3 Temperature Threshold°C/ °F
Bin 4 Temperature Threshold°C/ °F
Threshold – Daily Hours of Insufficient LoadHr