Performance Monitoring for Efficiency

THOMAS ANDERSON, CCPEMILY CROSS, MASc, PEng, CEM

Burlington, Vermontcx‐associates.com

tom@cx‐associates.comtom@cx associates.comemily@cx‐associates.com

Efficiency Vermont is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to AIA/CES for AIA b C tifi t f C l ti f b th AIA b dAIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request.

This program is registered with AIA/CES for continuing professionalThis program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using,material of construction or any method or manner of handling, using, distributing, or dealing in any material or product.

Questions related to specific materials methods and services will beQuestions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

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Learning Objectives

Understand why performance monitoring is necessary

Learn how to apply real time performance monitoring economically and

effectively

Know which basic performance metrics to include on every project Know which basic performance metrics to include on every project

Understand the best approaches to long term performance data archiving

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Course EvaluationsIn order to maintain high‐quality learning experiences, please access the 

evaluation for this course by logging into CES Discovery and clicking on h C E l i li k h l f id f hthe Course Evaluation link on the left side of the page.

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Performance MonitoringPerformance Monitoring

• Part of the ongoing commissioning process forPart of the ongoing commissioning process for buildings and building systems

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What is Commissioning?What is Commissioning?

• Comprehensive QA process for buildings andComprehensive QA process for buildings and building systems

Soup to Nuts– Design Review– Equipment and Instrumentation Validation– Functional Performance Testing– Continuous Commissioning

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What is Commissioning?What is Commissioning?

• Comprehensive QA process for buildings andComprehensive QA process for buildings and building systems

Soup to Nuts– Design Review– Equipment and Instrumentation Validation– Functional Performance Testing– Continuous Commissioning

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What is Commissioning?What is Commissioning?

• Comprehensive QA process for buildings andComprehensive QA process for buildings and building systems

Soup to Nuts– Design Review– Equipment and Instrumentation Validation– Functional Performance Testing– Continuous Commissioning

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What is Commissioning?What is Commissioning?

• Comprehensive QA process for buildings andComprehensive QA process for buildings and building systems

Soup to Nuts– Design Review– Equipment and Instrumentation Validation– Functional Performance Testing– Performance Monitoring

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Case Study: BIA CxCase Study: BIA CxBurlington International Airport

Chiller Plant Upgrade AHU/Boiler Upgrade

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Case Study: BIA CxCase Study: BIA Cx

Burlington International AirportBurlington International Airport

Chiller Plant Upgradepg

Frictionless (Magnetic Bearing) Centrifugal ChillerTwo Fan Induced Draft Cross flow Cooling TowerBTU Meters with Insertion Turbine Flow Meters

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Case Study: BIA CxCase Study: BIA Cx

Burlington International AirportBurlington International Airport

HVAC Upgrade

R ft /VAV (2)Rooftop/VAVs (2)Condensing Boilers (2)Existing DuctworkExisting Ductwork

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Design ReviewDesign ReviewChiller Plant

• The control diagram at this time lacks the capability for facility operators monitor how much power the pumps and the chiller 

t th t d hillconsume…we suggest that pump and chiller KW values be imported into the DDC control system and displayed on the DDCsystem and displayed on the DDC graphics…display of chiller kW, tonnage, and a kW per Ton performance metrics.kW per Ton performance metrics.

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Design ReviewDesign ReviewChiller Plant

• The piping diagram calls for glass “stick” typeThe piping diagram calls for glass  stick  type piping thermometers.  These stick type piping thermometers are very difficult to read in thethermometers are very difficult to read in the field.  We suggest the use of round dial type piping thermometers. These are far easier topiping thermometers.  These are far easier to read in the field and will benefit facility operating staff.operating staff.

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Design ReviewDesign ReviewHVAC Systems

• Cross connects Cold/Hot duct cross connection: The new VAV boxes are shown connected to either the existing hot or cold duct mains…To mitigate main duct pressure losses, could the separate hot and cold d i b d li i fl ?duct mains be cross connected to equalize air flow?

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Equipment Checkout: LeaksEquipment Checkout: Leaks• Air Leaks:  loss of conditioned air

wasted fan energy– Existing ducts: seams joints corners not sealedExisting ducts: seams, joints, corners, not sealed

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Equipment Checkout: LeaksEquipment Checkout: Leaks• Air Leaks: loss of conditioned air

wasted fan energy– New equipment: damaged closure mechanisms and gaskets, as installed

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Equipment Checkout: LeaksEquipment Checkout: Leaks

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Equipment Checkout: Pressure DropEquipment Checkout: Pressure Drop • VAV box air inlet• 4 inch round duct runout installed• 6 inch round duct runout specified• 6 inch round duct runout specified• 4 to 5 times inlet static pressure drop

C0 = 19 C0 = 89

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specified installed

Equipment Checkout: Pressure DropEquipment Checkout: Pressure Drop 

• Piping strainer inaccessible• Piping strainer inaccessible

Roof

Top of

Strainer

Top of duct

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Equipment Checkout: RetrofitEquipment Checkout: Retrofit• Known Issue

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Equipment Checkout: RetrofitEquipment Checkout: Retrofit• Opportunities for Communication

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Equipment Checkout: Per Drawings?Equipment Checkout: Per Drawings?

• Cogged vs Standard fan V‐belts• Cogged vs. Standard fan V‐belts

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Equipment Checkout: Per Drawings?Equipment Checkout: Per Drawings?

• Counterflow pipingp p g

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Equipment Checkout: Air QualityEquipment Checkout: Air Quality• Standing water not permitted per ASHRAE 62.1• CHW pipe insulation remained to be installed, no drain

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Instrumentation: Gauges and SensorsInstrumentation: Gauges and Sensors

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Instrumentation: Gauges and SensorsInstrumentation: Gauges and Sensors• Pete’s plugs for validation of piping sensors and gauges• Round vs Stick thermometers are easier to read• Round vs. Stick thermometers are easier to read

specified installed

• Calibrate/compare against NIST certified test instruments• Location of thermostats and control system sensors

Avoid interference from direct sun or equipment exhaust– Avoid interference from direct sun or equipment exhaust

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Instrumentation: DDC Program ValidationInstrumentation: DDC Program Validation

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Instrumentation: DDC Program ValidationInstrumentation: DDC Program Validation

• Sensor scaling errors• Sensor scaling errors– 0 to 5 V or 0 to 10 V?Chill t l d di l d f d t b– Chiller percent load displayed found to be one third of actual per BTU meters

Ph i l h k• Physical checks– Outside air dampers found in a position other than commanded by the DDC system

– Too much outside air being brought in (expensive)

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Functional Performance Testing: ChillerFunctional Performance Testing: Chiller

• Chilled water pump rate of flow change• Chilled water pump rate of flow change found to be too rapid

• Minimum chiller flow was not maintained

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Functional Performance Testing: HVACFunctional Performance Testing: HVAC

• Software programmed with an• Software programmed with an economizer mode lockout when the 

td i t t d b loutdoor air temperature drops below 40F.

• Outside Air Control: configured for damper position rather than flow.damper position rather than flow.

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Functional Performance Testing: ControlsFunctional Performance Testing: ControlsChiller MER exhaust fan stays on after alarm clears

MER temperature > 80FMER temperature > 80FRefrigerant leak detection

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Up Next: Performance MonitoringUp Next: Performance Monitoring

Thomas Anderson@ itom@cx‐associates.com802.861.2715 x11

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Why Performance Monitoring?Why Performance Monitoring?

• How many miles per gallon is my building getting?

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Building Energy TrackingBuilding Energy Tracking

• How does my building compare to peer• How does my building compare to peer building?

• Am I using what is expected?• Has anything changed?Has anything changed?• Am I improving over time?

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System Energy TrackingSystem Energy Tracking

• Are systems behaving as they should?• How efficient are my systems?• Today’s performance vs 3 years ago?Today s performance vs. 3 years ago?

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System Energy TrackingSystem Energy Tracking

• Building energy efficiency depreciates 2% to 3% a year

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System Energy TrackingSystem Energy Tracking

Expectations for building operators:• Manage systems efficiently• But we do not provide efficiency ut we do not provide efficiencyfeedback in our designs

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Energy ManagementEnergy Management

You cannot manage… 

What you cannot measure…What you cannot measure

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What To MeasureWhat To Measure

•Building Service•Building Service‐ Electrical‐ Fuel

•Central Plants‐ HeatingCooling‐ Cooling

‐ Refrigeration

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Other Sub GroupsOther Sub Groups

•Key Lighting Circuits•Key Lighting Circuits‐ Exterior Lighting‐ Key Lighting Zones

•Computer Roomsp•Central Air Handlers•Central Pumps

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Devices

BTU MetersBTU Meters• Liquids:

‐ Heating Hot Water‐ Chilled WaterChilled Water‐ Domestic Hot Water

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Turbine Meters

•Closed Loop Fluids• Fairly Clean Water

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Turbine Meters

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Ultrasonic Meters

•Clamp‐on•Clamp‐on•Non‐Invasive•Good for Retrofits•Clean or Unclean Liquids•Clean or Unclean Liquids

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Ultrasonic

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Electromagnetic Meter

• Critical water flow applications• Critical water flow applications• Open loop• “Dirty Water”

‐ Gray WaterGray Water‐ Sea Water

d‐ Process Liquids

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Electromagnetic Meter 

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Power Monitoring

• Key Electrical Sub‐circuits• Key Electrical Sub‐circuits‐ Exterior Lighting / Interior Lighting

• Key large equipment‐ ChillersChillers‐ Large Compressors, etc…

P i El t i l S i P ibl• Primary Electrical Service – Possibly 

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Power Monitoring

•Measure True kW•Also:

‐ VoltageVoltage‐ Power Factor

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Power Monitoring

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VFD Power Loss

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VFD Power Loss IO

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VFD Power Loss – Network Interface

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Performance Metrics

Building Annual Energy:Building Annual Energy:• kBTU/Square Foot/Year

• EUI: Energy Use Index• “Miles per Gallon” for Buildings

• For Electrical and Fuels• Also: kWH/Square Foot/Year• Also: kWH/Square Foot/Year

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Unit Conversion

• Electrical:• Electrical:‐ kWH/YR x 3.41 kBTU/kWH

• Fossil Fuel:‐ Fuel Units/YR x BTU Per Unit/ 1,000Fuel Units/YR x TU Per Unit/ ,000

• Units Delivered to Building (not source  Energ )Energy)

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Information Presentation

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Cooling Plant

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Cooling Plant

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Typical Pump

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Cx of Performance Monitoring

Commissioning:Commissioning:• BTU Meters: Water• Upstream/Downstream straight piping• T&B Accuracy Verification• T&B Accuracy Verification

‐ vs. Balance Valve‐ vs. Pump Curve‐ vs. Equipment Pressure Dropq p p

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BTU Meters: Water

• Temperature• Temperature‐ +/‐ 0.1°F Accuracy Goal‐ Insertion Temperature Probe‐ ≈ with +/‐ 0.1°F Accuracy ‐ ≈ RTD Type: Not ThermisterMust Have Insertion Test Ports!‐ Must Have Insertion Test Ports!

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Power Meters

•Goal: +/‐ 0 1 kW (True kW)•Goal: +/‐ 0.1 kW (True kW)•3 Phase: Sum of 3 legs•Precision field meter required

‐ +/‐ $2 000 meter cost+/ $2,000 meter cost

• Stable operation required

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VFD Based Power

• +/‐ 0.1 kW Accuracy Goal• Compare VFD Display with building BMS• Check for 0 0 KW when off• Check for 0.0 KW when off 

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Data Acquisition

•Capture Related Data•Capture Related Data•Outside Air Temperature (All)•Cooling Plants

‐ OA EnthalpyOA Enthalpy‐ CHWS Temperature

d‐ Condenser Water Temperature‐ To Chiller

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Correlate Related Data

• Heating: BTUH vs Average Hourly OA TempHeating: BTUH vs. Average Hourly OA Temp• Fans: kW/kCFM/HR vs. Average Hourly OA TempTemp

• Cooling Plant‐ kW/Ton vs. Average Hourly Enthalpy‐ kW/Ton vs. Average Hourly Condenser Temp

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Data Management

Central PlantsCentral Plants• Data Frequency: Every Minute• Then 15 Minute Average• Then Hourly Average• Then Daily Average, etc...

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Data Management

• Too Much Data to Store• Too Much Data to Store•Develop Average Data

‐ For Permanent Storage

•Dump detailed data after +/‐ 90Dump detailed data after +/ 90 days or so

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Further Resources

“The Building Performance TrackingThe Building Performance Tracking Handbook,” California Commissioning C ll b tiCollaborative – cacx.org 

ASHRAE Guideline 22‐2008 –“Instrumentation for Monitoring CentralInstrumentation for Monitoring Central Chilled‐Water Plant Efficiency”

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Further Resources

CBECS – Commercial Building EnergyCBECS – Commercial Building Energy Consumption Survey

Benchmarking Building Energy PerformanceBenchmarking Building Energy Performance Oak Ridge National Laboratory –

eber ed ornleber.ed.ornl 

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Questions?

Thomas Anderson Emily CrossThomas Andersontom@cx‐associates.com

802 861 2715 11

Emily Crossemily@cx‐associates.com

802 861 2715 14802.861.2715 x11 802.861.2715 x14Visit our blog at: http://buildingenergy.cx‐associates.com/

110 Main Street110 Main StreetStudio 1BBurlington, VT  05401

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802.861.2715