Lalit Agarwal

Director Utility & Energy Management

University of Nebraska - Lincoln

Show of hands

• Energy & Utilities track graduates or current attendees

• You have “Energy” or “Utilities” in your core job description

• You pay utility bills or manage utility budgets

First Law of Thermodynamics: You can’t win

• Conservation of Energy

Energy In = Energy Out

• You can convert energy from one form to another but not create or destroy it (short of nuclear reactions)

Second Law of Thermodynamics: You can’t break even

• Every energy-conversion process involves losses – you never get all that you pay for

• “efficiency” is the % you didn’t lose

Examples:

• Boilers (stack losses, steam distribution losses)

• Chillers (mechanical losses to move “coolness”)

• Electricity (losses in distribution, transformers)

Energy use in typical house

Energy Inputs• Electricity• Natural Gas or

Heating OIl• Wood• Renewables

Energy Uses• Lights• Cooling• Heating• Hot Water• Appliances

How to conserve energy at home?

• Flip Chart Exercise

How to conserve energy at home?

• Turn off all the inputs and the consumption will become zero

• Reduce the outputs

• Turn it off when you are not using it

• Programmable Thermostats (NEST)

• Insulate attic and walls, and seal air leaks

• Use natural ventilation when weather is mild

• Use more efficient consumption devices• LED lighting• High-efficiency appliances

Energy use on typical campus

Energy Inputs• Electricity• Natural Gas• Heating Oil• Solid Fuels (coal,

wood)• Renewables

Energy Uses• Lights• Cooling• Heating• Hot Water• Appliances

Plant: steam, CHW, hot water

Same principle…..

• The principle is same….. with some additional considerations• Equipment class (commercial vs residential)• Humidity control• Increased comfort expectation• More complex building spaces and controls• Research spaces with special temperature, humidity,

ventilation and filtration requirements• SCALE

ASHRAE Climate Zone Map

Financing ECOs

• Institutional budgets• Utility budgets• Maintenance budgets• Sinking funds

• “Green Funds”• Establish nest egg, then use energy savings to replenish the

fund for sustainable energy savings program

• Energy Service Contractors (ESCOs)• 3rd party finance and installation (no up-front cost)• you share a portion of the savings with the ESCO

• Utility Company rebates

Lighting

• Lighting upgrades• LED lights are most efficient current technology• Maintenance savings as well as energy savings

• Exterior lights• Control with photocells (not timers)

High-efficiency and Variable Speed Motors• High efficiency Motors

• Almost always a good ECO for medium and large motors • Replace old motors rather than rewinding

• Variable speed• Match fan and pump speed to the actual need• Reset fan speeds based on feedback from end-use devices• Functions as a “soft start” to extend motor life (but old motors

may not be able to handle voltage changes)

Coil/Valve Maintenance

• Keep both air-side and water-side clean

• Clean strainers regularly

• Replace filters regularly

• Repair leaks

Building Insulation & Sealing

• Roof and wall insulation

• Energy efficient windows

• Insulation is hard to justify on energy savings alone (eg: insulate when reroofing anyway)

• Operate fans to keep building pressure just slightly positive relative to outside

• Beware of exhaust fans running when there is no AHU bringing fresh air into the building

Mechanical Insulation

• Unlike building insulation, insulating pipes and ducts is always a good idea• If it’s hot enough to burn you• If it’s cold enough to condense moisture

• Inspect Mechanical rooms for missing and damaged insulation yearly

Space Scheduling

• Turn off classroom and office AHUs when possible overnight and on weekends

• Try to confine after-hours classes to a few buildings or systems, and turn other AHUs off

• Adjust schedules for after-hour event requests

Occupancy Sensor

• Scheduled rooms are actually unoccupied a lot of the time

• Float room temperature in 2° deadband

• Reduce minimum ventilation

• Payback 3-5 years

Smart Thermostats (aka: DDC)

• Commercial HVAC systems often heat and cool at the same time (hopefully in different rooms)

• At UNL, we centrally adjust thermostat “deadband” configurations rather than changing setpoints

• With pneumatic or line-voltage thermostats, give occupants setpoint guidelines

Humidity Control

• Humidification is expensive• Minimize static electricity• Meet research and regulatory requirements

• Dehumidification is expensive• Prevent condensation and mold growth

Use Building Automation System (BAS) to optimize HVAC systems• Air Handler resets

• Supply air temperature• Only hot enough to satisfy room needing the most heat• Only cold enough to satisfy room needing the most cooling

• Supply air at pressure only high enough to satisfy VAV boxes or valves needing the most flow

Simultaneous Heating & Cooling

• Single biggest opportunity in most HVAC systems• Don’t use cooling coil when outdoor air is sufficiently cool• Don’t use preheat coil when outdoor air is not cold• Don’t use reheat coil when high humidity is not a concern• Don’t use constant-volume operation when not needed• Don’t overcool supply air (requires more reheat at rooms)

• Often hidden as valves leaking through – the coils are heating or cooling unnecessarily but coil valves indicate that they are closed

Maximize cooling coil delta-T

•ΔT (temperature change) is the amount of cooling you get from each gallon of CHW• Desirable ΔT is usually 10-14 degrees• Sometimes, it gets down to 2-3 degrees• This means you have to pump more water for the same cooling

• Replace 3-way valves with 2-way valves

• Pressure-independent valves maintain desired ΔT

• Don’t exceed coil flow design capabilities

Lab Operation Energy Savings

• Fume Hoods constantly exhaust air from lab experiments• Keep fume hood sashes closed except when loading • Don’t store chemicals in fume hoods• Put hood control in “standby mode” when possible• Don’t mute alarms – get malfunctions repaired

• Lab rooms constantly exhaust air to…• Maintain air pressure relative to surrounding rooms & corridors• Maintain minimum air changes per hour

• Put lab in “standby mode” when possible• Reduce air changes• allow temperature deadband

• Partner with Environmental Health & Safety!

Demand Control

• Electric Utilities often use a 2-part Billing Rate• How much electricity you use over a month - energy• How fast you use it at the peak time - demand• Demand cost can be up to half the total electric bill

• Demand savings isn’t really energy conservation, but it reduces your electric bill

• Control demand by not operating everything at full speed all at once, especially on hot afternoons

Thermal Energy Storage

• Make cold water or ice at off-peak hours

• Distribute as CHW during peak periods

• Doesn’t conserve energy, but reduces demand cost

Train Occupants in Good Habits

• Adjust thermostats appropriately

• Dress appropriately for the weather and building conditions

• Turn off unneeded lights, computers and office equipment

• Turn off unneeded exhaust fans

• Use window drapes/blinds appropriately• Winter – open in direct sunlight and otherwise closed• Summer – closed in direct sunlight and open (instead of electric lights)

when shaded

• Close the stupid fumehood sashes!!!

Energy Audits

• Level 1 – “walk-through” inspection• Low cost, ½-day or 1 day on-site survey• Recommend low- and no-cost opportunities• Identify capital opportunities for further analysis

• Level 2 – Energy survey and analysis• More detailed, involves measurements and monitoring• Preliminary cost-benefit analyses

• Level 3 – Detailed engineering analysis

• Audit is just a plan – It saves nothing by itself

Energy Mindset: “AND”

Systems

ProjectsProcesses

Energy Savings

Occupant Satisfaction

Operations Savings

Approach Outcome

Integration Drives Energy and Operational Savings

• Semi-annual Fan, Pump, and Motor PMs

• Average frequency reduced from 6 to 10.5 months

• 30% operational savings versus calendar-based PMs

Integration Drives Energy and Operational Savings

• 55% reduction in labor hours

• 50% fewer filters

• Reduced energy consumption

• Reduced environmental impact

• Improved Indoor Air Quality (IAQ)

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Filter Replacement Labor Hours

Hamilton Hall Chemistry LabFilter Savings

• Energy Savings: $8,700/year

• Labor Savings: $2,200/year

• Material Savings: $2,900/year

$0

$5,000

$10,000

$15,000

$20,000

$25,000

$30,000

$35,000

$40,000

Filter Savings

Energy Labor Material

Hamilton Hall Chemistry LabFilter Savings

• Energy Savings: $8,700/year

• Labor Savings: $2,200/year

• Material Savings: $2,900/year

$0

$5,000

$10,000

$15,000

$20,000

$25,000

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Filter Savings

Energy Labor Material

Time

Cost

None

Static Alarm

Performance

Performance Degradation and Cost Savings

Reduce Energy Consumption

Avoid catastrophic breakdowns

Resolve issues before occupant awareness

Degradation Curve Periodic Recommissioning

Periodic Recommissioning (RCx)

Continuous Commissioning with FDD

Time

Cost

None

Static Alarm

FDD

Air Handler Unit (30,000 CFM) Monetizing Fault Savings

Heating Energy Cost /year:

2,130 $/year

30,300 $/year

4,880 $/year

25,420 $/year 84%

Fault Detection versus Alarm Management

Degradation Curve

Ross Van Brunt Visitors CenterEnergy Savings

• Energy Use Index (EUI) decreased by 15.4%

• Identified additional energy conservation projects

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Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

kBtu

/sf/s

lidin

g 12

mon

ths

RVB - Energy Use Index

2014-2015 2015-2016

International Quilt MuseumEnergy Savings

• Original Building• 37,851 GSF• 9,249 MMBtu/year

• With Addition• 51,551 GSF (36% increase)• 6,519 MMBtu/year (30%

reduction)

• Energy Use Index (EUI) decreased by 48%

RCx Savings• 16% reduction in annual energy costs

Recommissioned Buildings BaselineCost

ActualCost

AvoidedCost

PercentSaved

ANDN - Andersen Hall $26,470 $26,957 -$487 -2%

ANSC - Animal Science Complex $312,359 $306,899 $5,460 2%

AVH - Avery Hall $83,390 $87,742 -$4,351 -5%

ENTO - Entomology Hall $35,944 $35,589 $355 1%

FMS - Facilities Mgmt Shops $59,802 $57,945 $1,857 3%

HARH - Hardin Hall $84,461 $80,338 $4,123 5%

KCR - Kiesselbach Crop Research $16,390 $12,771 $3,619 22%

KEIM - Keim Hall $71,877 $76,143 -$4,266 -6%

QH - Quilt House $279,333 $147,156 $132,177 47%

RVB - Ross Media Arts Center $98,068 $75,934 $22,134 23%

SHEL - Sheldon Art Museum $49,575 $35,153 $14,423 29%

Total to-date $1,117,670 $942,627 $175,043 16%

FDD Implementation and Fault Response

• Align BAS assets and integrate with ICONICS software

• Develop fault prioritization algorithms• Cost• Criticality

• Control Center triage• Identify root cause using BAS• Resolve issues remotely if possible• Dispatch field technician when necessary

Example Fault Response

If not repaired, thisfault wastes $220/yr

Room Setpoint

Room Temperature

VAV feedback (500 cfm)

VAV command

RHT cmd & feedback

normalcooling

VAVfails

constant, full cooling with reheat

Response: Control Center creates work order for zone technician to replace VAV actuator

C3PR: Marriage of Systems and Processes

VerifyRestore to ReliabilityDiagnosisDetailed

HandoffRemote Analysis

Customer Contact or

Fault Detection

Campus Event Management System (EMS) Integration

• Integrate reservation data from campus room-scheduling system to automatically adjust AHU schedules

• Match AHU operation with academic needs

• Reduce AHU run hours

• Eliminate manual updating of AHU schedules

Smart CHW Coil Valves

• Replace CHW control valves with smart valves• Programmed to maintain a minimum ΔT

• Extract maximum cooling energy from each gallon of CHW

• Reduce pumping energy from central utility plant

• Reduce campus peak electrical demand

Fumehood/Lab Initiative

• Focus on training lab users for proper operation – this combines safety and energy conservation• Proper sash operation, standby, and lab occupancy switch

• Single consistent message

• Provide data to EH&S for evaluation and action related to hood and lab operations

ASHRAE 36 StandardHigh Performance Sequences of Operation for HVAC Systems

• Recommended best practices for • Central HVAC system control• HVAC terminal unit room control• Automatic resets to minimize energy use• Fault-detection rules

• Most concepts are already implemented in UNL BAS

Energy Mindset: “AND”

Systems

ProjectsProcesses

Energy Savings

Occupant Satisfaction

Operations Savings

Approach Outcome

What makes our program possible?

Energy Savings

UTL Plant

BAT

EMAG

Maint.

BSA

FPC

Vision

Innovation

Investment

People

Collaboration

Questions?