making building systems sing in harmony retrocommissioning
TRANSCRIPT
Making Building Systems Sing in Harmony
Retrocommissioning in Vermont
Daniel Tuhus-Dubrow
Cx Associates
Presented by:
Agenda
What is Retrocommissioning?
The RCx program in Vermont
RCx Process
Common RCx Findings
Case Studies
Challenges and Opportunities
Retrocommissioning is…..
Process for ensuring systems and equipment are operating per the current facility requirements
Repairing Deficiencies
Optimization of Existing Building Operation
Measures are typically low or no cost to implement
Retrocommissioning is…..
Other Potential Benefits Operations and Maintenance Occupant Thermal Comfort Improved Indoor Air quality
Retrocommissioning is NOT…..
Capital improvement projects:
However… Equipment at the end of its useful life will often be identified through the RCx process.
Lighting retrofits
Equipment replacement
Window upgrades
Reducing Greenhouse Gas Emissions
Commercial buildings consume nearly half of the building energy used in the United States (around 20% of total U.S. energy consumption and greenhouse gas emissions)
RCx Potential
Saving Money
Median whole building energy savings of 16%
Median cost of $0.25 per sf
Median payback time of 1.1 years
RCx Potential
The RCx Program in Vermont
Programs from Efficiency Vermont and BED
Qualify Develop Implement Verify
Steps in Qualifying Phase
Pre-qualify
Walkthrough by team
Findings and Recommendations
Estimate energy savings
Development Phase
Document Baselines
Refine Savings Estimates
Develop Scopes of Work
Obtain Pricing for Implementation
Implementation Phase
Pay for performance
$0.10/kWh up to $25,000
Vendors implement recommendations
RCx Process
Building Energy Benchmarking
Review Available Documentation
Utility Data Analysis
Site Visits and Field Investigations
Trend Data Analysis
Measure Development
Implementation
Benchmarking
Energy Star Portfolio Manager
DOE Building Performance Database
Benchmarking
Building Documentation
Mechanical/Electrical Drawings
Controls Drawings
TAB reports
Previous energy assessments
Utility Data Analysis
Monthly Bills
Electric Interval Data
Delivered Fuels
Utility Data Analysis
Interval Data Analysis
Opportunity to Adjust Operating Schedule?
Interval Data Analysis
Interval Data Analysis
Occupied Baseload
Cooling Balance Temp
Cooling Demand
Interval Data Analysis
0 25 50 75 100
Site Visits
Meeting with Key Stakeholders
Systems Assessment
Datalogger Deployment
Targeted Testing
Kickoff Meeting
Teamwork
Have the
right people!
Team
Commissioning Engineer
Controls Contractor
Facilities Staff
Introduce Perspectives
Brainstorm
Identify Opportunities
Evaluate Merit
Building Walkthrough
Systems Assessment
BAS Remote Monitoring
BAS Remote Monitoring
Dataloggers
Trend Data Analysis
Verify existing control sequences
Are setpoints being maintained?
Is economizer operating properly?
Are resets working as intended?
Is equipment running per schedule?
Trend Data
Analysis
Spreadsheet based charting
Universal Translator
Dedicated analytics software
Other Tools
Trend Data Analysis
Trend Data Analysis
Methods for Estimating Savings
End Use Disaggregation
Engineering Calculations Bin Calcs Hourly Spreadsheets
Regression Models
Energy Simulation
Common RCx Findings
• Scheduling
• Economizer Operation
• Simultaneous heating and cooling
• Calibrating or relocating sensors
• Return Equipment to AUTO control
• Release BAS Overrides
• VAV box minimum flow settings
• Correct VFD settings
• Optimize Control Sequences
Operating Schedules
Throttled Valves
Stuck Dampers
Equipment Overrides
Damaged Sensors
Measure Development
Document baselines
Focused PFCs and FPTs
Refine savings estimates
Develop scopes of work
Obtain pricing
Project Case Studies
Building Types Hospitals Universities K-12 Schools Office Buildings Ski Resorts Food Processing Municipal
Projects Overview
N = 28 6,000 – 200,000 sf Median = 34,800
Projects Overview
> $350,000 potential savings 0.5 – 4.5 years Median = 1.9
Hospital AHU Optimization
Measure Summary
Dehumidification setpoints unnecessarily low (40-45%)
Economizer lockout setpoints unnecessarily low
Economizer controlling to MAT setpoint rather than SAT setpoint
Implement static pressure reset
Enable supply air temperature reset
Used Guideline 36 recommendations where possible
Verify calibration of controlling sensors
Unnecessary filters with higher efficiency than required
Hospital AHU Optimization
Pre Post
Challenges
Getting to Implementation Measure Persistence
Implementation
Facility buy-in
EVT / BED involvement
Incentives help
Measure Persistence
Training is KEY
Post-Implementation BAS Monitoring
Establish continuous energy improvement program
Opportunities
LARGE MARKET POTENTIAL
ONGOING COMMISSIONING
ENERGY MANAGEMENT INFORMATION
SYSTEMS
Ongoing Cx
Thank You!
Daniel Tuhus-Dubrow
Senior Engineer
Cx Associates
Burlington, VT
802-861-2715 x21