mike eardley, pe, leed ap, ccp director of commissioning cannondesign brian berg, jr., pe, leed ap,...
TRANSCRIPT
Mike Eardley, PE, LEED AP, CCPDirector of CommissioningCannonDesign
Brian Berg, Jr., PE, LEED AP, CSIPrincipalBerg Engineering Consultants, Ltd.
April, 2014
The Power of Retro-Commissioning
Illinois Healthy & HighPerforming Schools Symposium
•Commissioning (Cx) Definition•Cx Process•Cx Applied to Existing Buildings•Retro-Commissioning Examples•Human Factor in Buildings•Hot/Cold and Energy Concerns•Q&A
Agenda
High Performance Buildings
Characteristics• Functionality• Energy Efficiency• Indoor Environmental Quality• Comfort• Sustainability (ability to perform its function in a long term)
Building Systems Commissioning
• Buildings function as intended • Realize high system performance
• Promotes integration of systems• Document facility requirements
•Commissioning (Cx) is a comprehensive and systematic process to verify and document that new or renovated facility systems function completely as designed to meet the owner’s requirements
•Retro-Commissioning (RCx) is the commissioning of a building that has never been commissioned.
• Energy goals and low/no-cost measures often a focus
Commissioning Definition
Without Commissioning
• Placement and calibration of Sensors• Simultaneous Heating and Cooling• Incorrect function of air-side Economizer and other efficiency measures• Operating Schedule is not what is necessary, or assumed by energy model• Cycling daylighting and other systems
Energy Impacts
- Large effort in sustainable and energy efficient design- Will not be realized if design or intended use is:
misunderstoodignored
- Or if building systems are:operating incorrectlynot thoroughly tested
Purpose of Functional Testing
- Verification of an operational systemnot a trouble shooting exercise (in theory)
- Reduces adjustment and tuning during occupancy- Impacts
energycomfortmaintenancefunctionality
Types of Functional Testing
- Building Automation System- False load- Seasonal testing- Trend analysis
•Commissioning: Process applied to new construction or major building renovation
•Re-commissioning: Facility has previously been commissioned and is in need of a “tune-up”
•Retro-commissioning: Performed on facilities that have been in service and never commissioned
•Ongoing commissioning: Ongoing program of structured commissioning throughout the lifetime of a building
New and Existing Buildings
•Definition: Commissioning a building that never has been
• In practice: re-tuning systems
•Or, identify low-cost / no-cost measures to implement
• Site survey, owner interview, trending
•Drawings study, engineering calculation
Retro-Commissioning Process
• Energy measure identification
• Implementation
•Measurement & Verification
• Persistence
• SEDAC Retro-Commissioning Program
•ComEd Retro-Commissioning Program
Retro-Commissioning Process
Trending
- Functional testing before occupancy is a snapshot- Trending shows operation over time- Methods of trending
building automation systemportable data loggers
- Analyze trendsspreadsheet calculationssoftware tools
Ongoing Commissioning
- GoodCx process with
functional testing- Better
Re-Cx program- Best
Ongoing Cx- Combination of software,
engineering support, action
•Document current operation
• Identify opportunities for improvement
• Evaluate payback, consider measures
• Implement measures
• Verify measures
LEED for Existing Buildings
Typical Air Handling Unit
Typical Air Handling Unit – Components
economizervariable air
volume
hot water heating
chilled water cooling
Moving Parts
Common Problems – Air-side Economizer
- Damper is stuck / broken / non-functional- Control algorithms fighting
heating during economizermechanical cooling when free
cooling available- Outside sensor calibration or location
static pressure reset
supply air temperature reset
hot water reset
chilled water reset
demand control ventilation
zone level CO2 control
Controls
morning warm-up
occupied / unoccupied
Scheduling