Objective/ Method/Outcome
Objective: Determines if the exhaust air Energy Recovery Wheel is being effectively utilized during the cooling season.
Method: Compares the Exhaust Air Temperature, Outdoor Air Temperature, and Supply Air Temperature to the Energy Recovery Wheel status. If the Energy Recovery Wheel is inactive while conditions are suitable for cooler exhaust air to lower the temperature of warmer outdoor air, the hours of faulty operation are calculated. Avoidable Cost and Potential Savings are calculated based on the Electricity Rate.
Description
Reference: ASHRAE90.1-6.5.6.1
This rule is applicable for exhaust air heat recovery. In cooling season, cooler exhaust air can be used to reduce hot outdoor air temperature before it’s exhausted outside.
This rule is part of the CopperTree Standard rule-set. (Aliased Celsius)
Default Priority
Medium
Diagnosis
1. Related sensor(s) error
2. Review control sequence
Message
Energy recovery is not fully utilized in cooling season.
Rule Template
Insight Type: Energy
Trigger Type: Active High
Notes
1. Expected values for “SF Status” inputs are “0” or “1”.
2. Expected values for “Supply Fan Speed” inputs are “100” if they are constant speed fans.
Default Thresholds:
Threshold – Weekly Hours of Faulty Operation: 14
Heat Recovery Activate Delta-T Threshold [*C]: 2
AHU Rated CFM: 10000
Electricity Rate($/kWh): 0.1 Weeks of Operation: 26
