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Energy Efficient OperationsLaura Millberg, MPCA
(adapted from a presentation by Garrett MosimanCenter for Sustainable Building Research
College of Design, University of Minnesota)
What is the Goal of Energy-Efficient Operation?
To ensure that each significant energy-consuming device uses only as much energy as necessary to perform
its intended function!
(Does not result in personal discomfort or complaints)
Problems Achieving this Goal
• Easy to use more energy than necessary• Wasted energy goes undetected:No discomfort for occupantsNo complaints to building operatorsRoutine preventive maintenance does not find it
• Little accountability to detect wasted energy• No established methodology• Checking everything is not practical
Solution: Detection can be Easy & Inexpensive
If the detection tasks:target the largest vulnerabilitiesuse available performance datafocus on determining if wasted energy is occurringrequire minimal skills to identifyare performed as seldom as possible
What are the Largest Vulnerabilities?
Chart courtesy of Center for Energy and Environment based on recommissioning studies.
Is wasted energy occurring? (example: excessive air handler runtime)
Solution:B3 Energy Efficient Operations “Manual”• Online tool• Creates customized,
easy-to-use protocols Lighting timer control
schedules AHU timer control
schedules AHU air temperatures
• Useful for facilities management and building operations staff
B3 Energy Efficient Operations “Manual” tab:
Negotiate Shortest Possible Schedules
(Schedule of Operations is largest vulnerability)
Step 1: Review Area Served by AHU
Step 2: Contact Negotiation Participants and Ask Key Questions• What is acceptable range of temperature and humidity?• What time in the morning should conditions be in that range?• How long does it take for AHU to achieve these conditions each
day of the week? Each season?• What is latest possible morning start time each day of week?• At what time in the afternoon/evening can it go out of range?• How long after shutdown do conditions go out of range?• Are operating hours extended for custodial activities & can
these hours be reduced/eliminated?
Step 3: Record changes to the schedule
B3 Energy Efficient Operations “Manual” tab:
Verify Schedules in The Timer
Scroll Down to name of timer control Click the "+" next to the name.
Use the fields in the popup window to modify the schedule.
Steps 1-3: Log in to timer control; compare schedule in timer to current schedule; change timer schedule if they do not match
B3 Energy Efficient Operations “Manual” tab:
Verify Timer Operations
Step 1: Review verification processStep 2: Consult schedule to find time when AHU should be offStep 3: Perform AHU check
Verify Timer Operations
"On" Event
Su Mo Tu Th Fr SaWe
Malfunction indicated--fan energy use at night
Verify Timer Operations (cont.)
To confirm that AHU2 is off, stand next to the unit and verify:1) -Fan VFD controls read zero2) -No fan noise can be detected3) -The cabinet of the AHU is not vibrating
If these three checks verify the unit is off, then assume the "off" control command was executed correctly.
Verify Timer Operations (cont.)
• Find "Supply Fan 1A and 1B Command." Verify the command is "off.“
• Find "Supply Fan 1A and 1B Flow." Verify the flow is below 50 cfm.
• Find "Discharge Air Pressure." Verify it is below .05 in wc.
If these criteria are not allmet, initiate corrective action.
B3 Energy Efficient Operations “Manual”
Web application is online, welcoming pilot buildings:
8 system checks supported, more on the wayAutomated email alerts when tasks are dueAutomated reporting to facilities manager when
malfunctions are discovered
If you have a building you’d like to pilot, contact:Metro area: Katie Hosch, [email protected] MN: Garrett Mosiman, [email protected]
