PSSRB Vivarium Monitoring Based
Retro-Commissioning
Jamie Hand
Campus Energy Manager
UCSF
7/8/2016
Adam Wheeler, P.E.
Sherrill Engineering, Inc.
Project Results
 Total costs: $510,030
 PG&E Incentive: $394,000
 Annual Utility Savings: $220,000
 Payback period: 6 months
Electricity (kWh)
Steam (therms)
Chilled Water (tons)
CHW (peak tons)
Baseline
Post-MBCx Savings
% Savings
2,760,453
1,402,251
1,358,202
49%
229,213
182,689
46,524
20%
385,765
148,654
237,111
61%
274
109
165
60%
kWh/day
2
Implementation
Period
7/8/2016
Building/Project Description
 Specialized Vivarium Building
 Constructed 2003-2005
 80,000 ft2 and 6 floors, 250,000 mice
 4 floors devoted to lab animal housing and support spaces
 Fully ventilated (Independent Supply and Exhaust) cage racks
 Continuous lab animal occupancy; 100% Outside Air ventilation
Utilities and Mechanical
 Electricity fed from cogeneration plant
 Plant Steam for HHW generation, Humidifiers and Processes
 Plant Chilled Water, adequate pressure (no pumping in bldg)
 ~ 420 Pressure independent VAV Airflow Control Valves with
Vortex shedding airflow measurement and HW reheat
 DDC controls throughout building
Typical floor plan
Baseline Development
Metering
 Steam meter
• Existing Vortex meter oversized (1000 lbs/hr min)
• Replaced with Orifice plate meter (500 lbs/hr min)
‒ In retrospect, should used smaller pipe size to get lower min
reading
 Chilled water meter
• Turbine type meter had stopped functioning
• Replaced with insertion mag-flow meter
• Electric metering by campus SCADA system
Cost Detail
 Metering purchase and install: $20k
 Cx Consultant: ~$100k
 In-house engineering: $11k
 In-house controls: $104k
 Energy Analyst: $24k
 Facilities Services: >$100k
 Motion sensor install: $28k
 Insulation: $10k
 PM: $33k
- controls contractor
- insulation contractor
 BMS data Analytics Package: $25k
Retro-Commissioning Overview
 Analyze Building Operations
• Where is Energy Being Used
• What are the current Owner’s Requirements?
 Develop Energy Conservation Measures (ECM’s)
• Analysis, Planning, Preparation
• Estimate “costs” and savings, rank, choose some, defer others
 Develop Functional Improvement Needs
• Integrate with ECM’s where feasible
 Complexity and Detail must be embraced to achieve best savings
• Central Systems may be easier, but lots of savings in Zones
Energy Conservation Measures (ECM’s)
 Consultant recommended about 30 ECMs
• Vast majority were controls logic changes
 Examples:
• Static pressure and temp reset (SA, EA, HHW) with deadband
• Eliminated bypass flow; Opened HHW reheat balance valves
• Motion Sensors & Schedules for Human occupied spaces
‒ Standby mode for unoccupied / unused spaces
• Airflow and Temperature Set Point adjustments
 Not all measures implemented due to time & effort “budget.”
Typical Small Animal Room
Small Animal Room ECM’s
Example ECM: Small Animal Rooms
 Current Use: Less racks than original design
 Result: More air than the needed
 Solution: BMS calculates flow SP based on # of racks in room
• Relies on communication between users and operators
 Actual occupancy determined by detailed audit
 Airflow changes carefully validated at cage level to assure
ventilation effectiveness
 Low ventilation issues found and corrected – Function Improvement
 Labor intensive but worth it!
Example ECM: Animal Support Rooms
 Existing condition: Procedure Rooms ventilated 24/7, but little used
 Solution: Install motion sensors to determine occupancy
 Depending on use, sensitivity, etc. the room airflow could be either;
• Turned off when unoccupied
• Turned down whenever unoccupied
• On during normal hours, reduced ACH off-hours when no
occupancy sensed (most sensitive areas)
Innovation: SA/EA Static Pressure Reset
Rank all supply air (SA)
valves by pressure
requirement (how much
they are opened), then
divide into deciles
(10 equal groups)
Adjust static pressure to keep
“second decile” average at a
set point determined to satisfy
all critical zones
Most open air valves
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Least open air valves
Many faulty
valves here
“Second Decile”
Innovation: SA/EA Static Pressure Reset
 Existing Control: fixed static pressure
 New strategy – Reset static pressure as follows:
• Pull Air Flow Control Valve (AFCV) position for all zones
• Create setpoint for average position of subset (via testing)
• Initially: lots of ‘problem’ zones w/ dampers 100% open
• Use DDC alarms to address outliers
 Controls and building engineers worked to greatly the reduce the
number of ‘problem’ zones –Functionality Improvement
Innovation: Stop “Creep” due to Hysteresis
Innovation: Stop “Creep”
 Existing: Airflow Control Valve (AFCV) plus airflow measurement
causes static pressure to “creep” up due to mechanical hysteresis
• Airflow overshoot compresses spring in AFCV
• Transient underflow opens valve, calling for more system static.
 New Strategy – Drop System Static pressure to relax springs
• Every four hours static pressure set point is dropped 10%
• System seeks optimum static pressure “from below”
• Static Pressure Set Point “Creep” Controlled
Elements Contributing to Project’s Success
 Differences between design and actual use (100% vs. 50% 24/7)
 Single user controls building, bought-in to project
 Detailed knowledge of building needs
• Commissioning agent (CxA) performed detailed new bldg Cx
• CxA had detailed knowledge of process needs & equipment
 Critical nature of building dissuaded prior optimization
• Functionality & Schedule main concern for new building
 Sophisticated in-house resources: Controls, Engineering, Maint.
 Zone-by-Zone ECM’s had to overcome skepticism about value
 Team willing to invest resources and Persevere (2.5 years)!
Recommendations for Future MBCx
 Pick a building with ‘modern’ controls down to zone level (DDC)
 Zone-by-zone analysis labor intensive but worth it. Review every
zone to determine:
• What are ventilation, pressurization, temp requirements?
• How is space used? Can we use motion sensors for setbacks?
 Create and evaluate wish-list (BMS upgrades, flow
measurement, TAB work) early in project
 Create written sequences that are detailed, even if controls
changes are being done in-house
 Pull tasks in-house where possible (save $ for implementation)
 Consider / Plan Follow-on Project to leverage knowledge gained.