The Stone House Group Tel 610.868.9600 Fax 610.868.2272 www.stonehousegroup.net Retro-Commissioning: 1 Getting the most from your buildings Dan Brown PE, CCP, CEM, LEED-AP THE STONE HOUSE GROUP
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Retro-Commissioning:
1
Getting the most from your buildings
Dan Brown
PE, CCP, CEM, LEED-AP THE STONE HOUSE GROUP
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
2
• Founded in 1999 on three pillars of
facilities management: operations, technical services and finance
• Dedicated to strengthening the mission and unique needs of our clients
• Focus on facilities
and technical services
progressed to include
sustainability consulting
Company Profile
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Retro-Commissioning
• What is retro-commissioning?
• Why is it done?
• How is it done?
• When is it a good idea?
3
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
What is Commissioning?
• Building commissioning (new construction)
• Retro-commissioning
• Recommissioning
• Continuous commissioning
4
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
New Building Commissioning
• Commissioning: – A systematic process to ensure the design,
installation and operation of systems meet the owner’s project requirements
• Key elements: – Design review
– Installation inspections
– Functional testing
5
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
New Building Commissioning
• Timeline – Ideally begins early in design phase
– Should cover occupancy and warranty period
• Scope – Minimum of energy-consuming MEP systems
– Can include fire protection, communications, envelope, security or other systems
6
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
7
Commissioning provides continuity, bridging the gaps between different phases of construction from OPR through occupancy
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
New Building Commissioning
• Process commissioning: – CxA develops installation checklists &
functional forms
– Contractor fills out forms and performs tests
• Technical commissioning: – CxA develops installation checklists &
functional forms
– CxA inspects installation and performs functional performance testing
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The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
New Building Commissioning
• Equipment startup is not commissioning – Startup:
• Does the chiller run?
– Commissioning • Should the chiller be running? • How do I maintain the chiller so it keeps running? • At what load should the chiller be running? • Is this the best chiller to use? • Is the chiller running efficiently? • Is the chiller having the desired effect on integrated
systems and space conditions? 9
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
10 Installation does not always meet the design intent
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Retro-Commissioning
• California Commissioning Collaborative: – Retrocommissioning is a process that seeks
to improve how building equipment and systems function together … Retro-commissioning improves a building's operations and maintenance (O&M) procedures to enhance overall building performance.
11
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Cx vs RCx: Approach
• Retro-Commissioning: – Uses technical approach
– Focuses on energy, comfort issues
– Mostly control improvements
– Compares current operation to current and future facility needs
– Fast payback items
12
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
13
Frequency of Implemented Measures in RCx Projects
Average Simple Payback (Years) by Type
Data Source: Mills, E., 2009. “Building Commissioning: A Golden Opportunity for Reducing Energy Costs and Greenhouse Gas Emissions”
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Cx vs RCx: Resources
• New building commissioning:
Owner’s Rep, Engineer, General Contractor, Subcontractors
Drawings, submittals, as-builts, O&Ms, RFIs, ASIs, OPR, BOD 14
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Cx vs RCx
• Retro-commissioning resources:
Limited or no engineer, GC or contractor availability
Whatever documents are available
Facility staff and occupants 15
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Why Retro-Commission?
• High operating cost – Building energy cost
– Maintenance & service calls
– Equipment life cycle
• Optimized runtime
• Ladder of reactive, preventive, predictive maintenance
16
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Why Retro-Commission?
• Comfort control – Space temperature too hot or cold
– “Stuffy” air; poor ventilation
– Drafts or pressurization issues
– Poor controllability
– Moisture or mold potential
• Code requirement – Sector (eg hospitals)
– Local code 17
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Why Retro-Commission?
• Changes to space use
• Adjustments to building systems
• Improve sustainability
• Marketing edge and improved image
• Building was never commissioned
• Over 5 years since recommissioning
• Increase building value 18
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Why RCx: Energy Cost
• O&M Best Practice Guide: – 5%-30% energy reduction
– Simple payback typically less than 2 years, often less than 0.5 years
• DOE – Typical energy cost over $2/GSF
– Typical RCx savings of 10-20%
– RCx median cost of $.30 per GSF (2009)
– Typical payback slightly over 1 year 19
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Why RCx: Energy Cost
• Lawrence Berkeley National Lab (‘04): – 5%-15% electricity
reduction
– 1%-23% gas
reduction
– 0.2 to 2.1 years
simple payback
20
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Why RCx: Comfort & Air Quality
• Rocky Mountain Institute: – Offices salaries are 72 times energy costs,
92% of the life-cycle cost of a building
– 1% increase in productivity (production rate, quality, or absenteeism) can provide savings to a facility exceeding its entire energy bill
• Lawrence Berkeley National Lab: – $23-56 bn. health care savings potential
– $20-160 bn. in worker performance 21
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Why: Asset Value
• Energy reporting: – Cities (eg Washington DC, Philadelphia, NYC,
Boston) and states (California, Washington) now requiring energy reporting
• Lower operating costs translates to: – Higher lease/occupancy rates
– Higher asset value
22
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Retro-Commissioning Process
• Planning
• Investigation
• Implementation
• Hand-off
23
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Process: Planning Phase
• Select a building
• Define objectives – Testing & tuning system operation
– Energy investments
– O&M strategies
– Procurement
– Training & documentation
– Air quality—noise, CO2, mold/moisture 24
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Process: Planning Phase
• Select a commissioning provider – Referrals, bid posts, trade organization
websites
– History of RCx, energy
– Match expertise to goals
– RFP/RFQ must define minimum qualifications and requirements as well as building information.
25
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Process: Planning Phase
• Building walkthrough – Review by CxA and Owner
– Determine areas of focus
• Develop RCx plan – Building information
– Roles and responsibilities
– Systems to be tested
– Deliverables
– Project timeline and hand-off 26
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Process: Investigation Phase
• Kick-off Meeting – Owner, facility staff, CxA, contractors
– Establish roles
• Review documentation – Drawings, as-builts, O&Ms, submittals,
utility bills, interval data, PM plan, operating requirements (temp, humidity, ventilation)
27
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Process: Investigation Phase
• Review current conditions – Energy use, control systems, operating
procedures
– Current issues, future plans
• Test building systems – Functional test forms
– Sequences of operation
– Building trend data, seasonal testing
– Non-ATC systems: Balancing, lighting
• Review technology – Eg Lighting, BAS, CO2 sensors, VFDs
28
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Process: Investigation Phase
• Document findings – Issue, recommendation, contractor
– Energy recommendations
– Provide priority or cost estimates
– Qualitative effects
• Plan for implementation – Review findings with RCx team
29
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Process: Implementation Phase
• Turn-key method – CxA manages implementation
• CxA-assisted – CxA assists, Owner manages contractors
• Owner-led – Owner manages implementation
• In-house expertise, time are largest factors in selection 30
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Process: Implementation Phase
• Implementation plan – Developed by CxA
– Issues to be rectified, acceptance criteria
• Implementation report – Testing of system adjustments
– Final status recorded
31
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Process: Hand-Off
• Persistence strategies – Training avoids:
• Equipment in hand, 24/7 schedules
• Overridden OA damper, temperature setpoint
• Valves closed
– Adjustable points & authority levels
– Ongoing technical support
– Policies and documentation
– Trending and alarming
32
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Process: Hand-Off
• Close-out meeting – Next steps
– Remaining issues
– Provide documentation
• Final report
• Control sequences
• Equipment inventory and as-builts
• O&Ms
33
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Process: Hand-Off
• Final report – Findings & implementation
– Control sequences & documentation
– Future commissioning recommendations
– Further energy/investment opportunities
34
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Process: Next Steps
• Energy performance tracking – Indicator of persistence
– Tool for future building investments, selection
• Re-Cx and continuous commissioning – Recommission approx. every 5 years, varies by:
• Complexity
• Detail of continuous commissioning
• Energy cost and consumption
• Changes to space use, building systems 35
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
36
Process: Sample Issues
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
37
RH of 11.7% while raining.
Uncalibrated RH sensor
can cause improper
economizer control. OA
temperature often used for
equipment enabling.
Code-required
exhaust air damper
not installed.
Exhaust fan
command remains at
minimum because of
unachievable space
pressure setpoint. Space pressure
erroneous due to
improper
placement of
sensor terminals.
Economizer (free
cooling) available,
desirable, but OA
damper remains at
minimum.
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
38
Unit programmed to cool
to the heating setpoint.
Cooling setpoint found to
be dummy point.
General graphical
issues with damper
and energy recovery
wheel display.
False loading at fully-
closed hot water
valve.
Chilled water PID
loop does not allow
effective response;
overheated air
results.
Lack of exhaust flow
disables possibility
of utilizing energy
recovery
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
39
Use occupancy sensor to
relax setpoints when
space is not in use.
CO2 sensor can
optimize fresh air
intake to reduce
energy consumption.
Fan cycling or speed
control can by employed
depending on
circumstances.
Currently on/off.
Optimized
start/stop,
unoccupied pre-
cooling or other
measures can be
used.
Improve
notifications so
faulty conditions
don’t persist.
Optimize control
with variable-speed
wheel control.
Process: Sample Opportunities
Separate actuators
allow optimized
damper control.
Dual-setpoint control
method can lead to
hunting and competition.
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
40
Process: Sample Opportunities
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Making the Most of RCx
• Best payback if buildings have: – Never been commissioning
Likely more opportunities for optimization
– Newer HVAC systems
Longer lifespan to accumulate savings
– DDC control
Allows control improvements at low cost
– High energy intensity
Greater savings for same cost
See Portfolio Manager or benchmarking tools
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The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Making the Most of RCx
• Best payback if buildings have: – Large HVAC systems
Use more energy
– Critical systems
High energy users, can have qualitative benefits
– Large square footage
Economy of scale
– Comfort or air quality issues
Can be a symptom of inadequate controls
Qualitative and productivity benefits
42
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Making the Most of RCx
• Best payback if buildings have: – Utility incentives
Increase the ROI
– Documentation
Assists in determining intent
• CxA can assist in determining best candidates for RCx.
43
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Making the Most of RCx: Incentives
• Delmarva – Up to $.13/GSF or $26,000
– Further incentives for continuous commissioning
• PEPCO – Up to $.11/GSF or $22,000
– Further incentives for continuous commissioning
44
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Making the Most of RCx: Incentives
• SMECO – Efficient equipment incentives
• FirstEnergy – Efficient equipment incentives
• Baltimore Gas & Electric – Up to $15,000
• Terms vary by utility; CxA can help facilitate incentive payments 45
The Stone House Group
Tel 610.868.9600 Fax 610.868.2272
www.stonehousegroup.net
Questions?
46
Dan Brown
PE, CCP, CEM, LEED-AP THE STONE HOUSE GROUP