028 Integrated Chiller Optimization
GPG FINDINGS
028
SEPTEMBER 2016
CONTROL OPTIMIZATION SYSTEM FOR CHILLER PLANTS
OPPORTUNITY What is the impact of improved chiller operations on GSA?
80% OF GSA FLOOR SPACE IS IN LARGE BUILDINGS The majority of which is cooled by chillers1
TECHNOLOGY How does the Control Optimization System for Chiller Plants work?
OPTIMIZES SYSTEM PRESSURE AND TEMPERATURE DIFFERENCE (DELTA T) MANAGES CHILLER LIFT AND FLOW BY MONITORING AND CONTROLLING FIVE INTERDEPENDENT SYSTEMS Cooling Towers (CT), Chillers (CH), Condenser Pumps (CTP), Chilled Water Pumps (CHP), and Air Handler Units (AHU)
AHU CT-1
CT-2
CT-3 AHU
CTP
CTP
CTP AHU
CH-1
CH-2
CHP
CH-3
CHP
CHP
Warm water Cool water
M&V Where did Measurement and Verification occur?
PACIFIC NORTHWEST NATIONAL LABORATORY assessed the control optimization system for chiller plants at the Frank M. Johnson Jr. Federal Building and U.S. Courthouse in Montgomery, Alabama
RESULTS How did the Control Optimization System perform in M&V?
35
5
BETTER
+/- 10% uncertainty
At avg. cost of $0.11/kWh3
FOR PLANT OPERATIONS2
%
COOLING SAVINGS due to estimated baseline1
YR PAYBACK
VISIBILITY & CONTROL
Increased Efficiency, Especially at Part Loads 5.0
5.0
4.5
4.5
4.5
4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5
Chiller 3 Average Efficiency (kW/ton)
5.0 Chiller 2 Average Efficiency (kW/ton)
Chiller 1 Average Efficiency (kW/ton)
Performance averaged 0.64 kW/ton after control optimization
4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5
0.0 200 400 600 800 1000 Total Secondary Tonnage
4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5
0.0 0
Before After
0.0 0
200 400 600 800 1000 Total Secondary Tonnage
0
200 400 600 800 1000 Total Secondary Tonnage
DEPLOYMENT Where does M&V recommend deploying the Control Optimization System?
CENTRIFUGAL CHILLERS WITH LOADS > 3 MILLION TON-HRS/YR Also consider for incorporation into new all-variable-speed chiller plants, where both installation costs and energy savings may be lower.
Optimization of Variable Speed Chiller Plants: Frank M. Johnson Jr. Federal Building and U.S. Courthouse, Montgomery, Alabama, JC Hail, DD Hatley, RM Underhill (PNNL), August 2016, p.13 2 Ibid, p.7 3 Ibid, p.38 4 Ibid, p.7 1
The Green Proving Ground program leverages GSA’s real estate portfolio to test innovative building technologies and provide recommendations on their deployment. www.gsa.gov/gpg
028
SEPTEMBER 2016
CONTROL OPTIMIZATION SYSTEM FOR CHILLER PLANTS
OPPORTUNITY What is the impact of improved chiller operations on GSA?
80% OF GSA FLOOR SPACE IS IN LARGE BUILDINGS The majority of which is cooled by chillers1
TECHNOLOGY How does the Control Optimization System for Chiller Plants work?
OPTIMIZES SYSTEM PRESSURE AND TEMPERATURE DIFFERENCE (DELTA T) MANAGES CHILLER LIFT AND FLOW BY MONITORING AND CONTROLLING FIVE INTERDEPENDENT SYSTEMS Cooling Towers (CT), Chillers (CH), Condenser Pumps (CTP), Chilled Water Pumps (CHP), and Air Handler Units (AHU)
AHU CT-1
CT-2
CT-3 AHU
CTP
CTP
CTP AHU
CH-1
CH-2
CHP
CH-3
CHP
CHP
Warm water Cool water
M&V Where did Measurement and Verification occur?
PACIFIC NORTHWEST NATIONAL LABORATORY assessed the control optimization system for chiller plants at the Frank M. Johnson Jr. Federal Building and U.S. Courthouse in Montgomery, Alabama
RESULTS How did the Control Optimization System perform in M&V?
35
5
BETTER
+/- 10% uncertainty
At avg. cost of $0.11/kWh3
FOR PLANT OPERATIONS2
%
COOLING SAVINGS due to estimated baseline1
YR PAYBACK
VISIBILITY & CONTROL
Increased Efficiency, Especially at Part Loads 5.0
5.0
4.5
4.5
4.5
4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5
Chiller 3 Average Efficiency (kW/ton)
5.0 Chiller 2 Average Efficiency (kW/ton)
Chiller 1 Average Efficiency (kW/ton)
Performance averaged 0.64 kW/ton after control optimization
4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5
0.0 200 400 600 800 1000 Total Secondary Tonnage
4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5
0.0 0
Before After
0.0 0
200 400 600 800 1000 Total Secondary Tonnage
0
200 400 600 800 1000 Total Secondary Tonnage
DEPLOYMENT Where does M&V recommend deploying the Control Optimization System?
CENTRIFUGAL CHILLERS WITH LOADS > 3 MILLION TON-HRS/YR Also consider for incorporation into new all-variable-speed chiller plants, where both installation costs and energy savings may be lower.
Optimization of Variable Speed Chiller Plants: Frank M. Johnson Jr. Federal Building and U.S. Courthouse, Montgomery, Alabama, JC Hail, DD Hatley, RM Underhill (PNNL), August 2016, p.13 2 Ibid, p.7 3 Ibid, p.38 4 Ibid, p.7 1
The Green Proving Ground program leverages GSA’s real estate portfolio to test innovative building technologies and provide recommendations on their deployment. www.gsa.gov/gpg
