Chiller Efficiency is low

Objective/ Method/Outcome

Objective: Determines if the Chiller Efficiency is low.

Method: Compares the chiller’s entering and leaving temperatures and flowrate to determine if Chiller is working efficiently.

Outcome: This rule triggers an insight.

Description

Reference: ASHRAE90.1-6.8.1

Chiller COP is calculated and an insight will be generated if it’s lower than threshold

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

Default Priority

Medium

Diagnosis

1. Please check is chilled water supply temperature or condenser water supply temperature is in normal range.
2. Check if chiller is out of maintenance.
3. Review and update chiller sequencing, if required.

Message

Chiller Efficiency is low.

Rule Template

Insight Type: Energy

Trigger Type: Active High

Notes

1. Only one “Flowrate”, [LPS] or [GPM] is needed.

2. Expected values for “Pump Status” inputs are “0” or “1”.

3. Expected values for “Chiller Status” inputs are “0” or “1”.

4. Expected values for “Pump Speed” inputs are “100” if they are constant speed pumps or not available.

5. The input(s) that is(are) not used should be set to “0”.

Default Values:

Const. – Daily Threshold of Faulty Chiller COP Operation [hrs]:2

Const. – Acceptable COP Threshold: 5

Const. – Weeks of Operation: 26

Const. – Energy Rate [$/kWh]: 0.1