HVAC Retro-commissioning Sustainable Savings with a Three-Prong Approach using Itron EEM Suite Brian Roberts & N. Amar Amarnani County of Los Angeles - ISD 1
Overview Process of HVAC retro-commissioning equest energy model to create baselines and estimate savings Tactical use of Itron/EEMIS for optimized HVAC operations A three-prong approach for sustainable savings equipment monitoring through EEM Suite utility bill analysis by means of Utility Accountant and system-level benchmarks using UCE+ module to help the HVAC systems running in optimized state. 2
What is RCx? New building systems should be commissioned systems should be checked to ensure they are operating per design Commissioning is often specified but rarely completed (budget overruns, schedule pressure) Restoring equipment to original design/operating conditions RCx (repairs and enhancements) Continually monitoring buildings to ensure systems are operating per design conditions Continuous Commissioning 3
Retrocommissioning (RCx) Partnership & Project Funding Funded by California Public Utilities Commission Partnership members Southern California Edison Southern California Gas County of Los Angeles 11 Facilities (1.6 million GSF) retro-commissioned Additional 3 Facilities (1.6 million GSF) funded by CAO Facilities maintained and operated by Internal Services Dept, County of Los Angeles 4
RCx Project - Defined Goals Optimize operations of Heating, Ventilation and Air Conditioning (HVAC) systems in the County buildings Identify optimization and energy efficiency measures Improve thermal comfort, ventilation and indoor air quality in the County buildings Develop tool for sustainable reduction of electricity and natural gas Provide operations staff will comprehensive facility information, update methods to efficiently operate, maintain and monitor HVAC systems 5
Defined Project Tasks Whole building energy benchmarking Diagnostic measurements Prefunctional testing of individual components Minor HVAC system repairs Building automation improvements Functional Performance Testing of HVAC systems Install new optimization energy efficiency measures Modeled energy savings projections System level benchmarks Retro-commissioning reports & schematics Training manual 6
Adapted RCx Process 7
County Buildings EUI Pre-RCx % of buildings w/ lower EUI 8 9 6 10 3,4 5 11 2 160 1 140 Natural Gas EUI Electricity EUI 127 139 Cal-Arch Chart EUI (kbtu/sf) 120 100 80 60 40 20 56 22 67 29 35 38 103 39 64 105 50 76 26 55 50 102 62 42 65 60 108 39 69 89 44 46 61 79 59 17 43 0 CM CH SM CH BH CH ML CH EM CH EL CH WH CH DN CH BL CH PL HQ SF CH 1 2 3 4 5 6 7 8 9 10 11 8
RCx+EEMIS+M&O=Optimized HVAC Optimized HVAC Building Operations HVAC RCx Project Funding Contract w/rcx Provider Optimize buildings Maintenance & Operations Continue optimized operations EEMIS Automation System-level Benchmarks Monitoring M&O Support 9
Public Library Headquarters equest Model Savings 10
HVAC RCx Measures Tested and calibrated all existing controls Improved Chiller Sequencing Installed customized Purge Cycles Optimized Economizer Controls Improved Boiler Combustion Efficiency Installed Boiler Hot Water Reset Controls Installed Discharge Air Reset Controls Improved VAV Static Pressure Controls Performed Diagnostic Air and Hydronic Testing Selective air balancing and terminal box repairs 11
Energy Efficiency Measure Projected Savings EEM Savings per GSF Optimized Schedule, Economizer and Discharge Air Reset (interactive) kwh per GSF 10.00 5.00 0.00 Dow Whitt EasL Bev ElMo Bellfl LibH San Mali Com DAT_kWh 0.52 0.09 0.08 0.03 0.12 0.04 0.69 0.03 0.58 0.16 Econ_KWh 0.89 0.58 0.15 0.06 0.58 0.46 0.17 0.02 0.39 0.10 OptiSch kwh 5.32 4.46 4.43 3.97 2.98 2.44 1.90 1.60 0.29 0.15 Facility OptiSch_kWh Econ_KWh DAT_kWh 12
RCx Cost & Utility Savings per GSF RCx Cost & Savings Indices $2.00 $2.00 $1.80 $1.80 $1.60 $1.60 $1.40 $1.40 $1.20 $1.20 $1.00 $1.00 $0.80 $0.80 $0.60 $0.60 $0.40 $0.40 $0.20 $0.20 $- DOWNEY CH PUBLIC LIBRARY HQ BELLFLOWER CH BEVERLY HILLS SANTA MONICA CH CH COMPTON CH MALIBU ADM/CH WHITTIER CH EAST LOS ANGELES CH EL MONTE CH - Rio Hondo SAN FERNANDO CH $- $ per GSF Savings rcx+impcost $ElecSav $GasSav Avg_rCxImpCost Avg_$Savings 13
RCx Utility Bill Saving First Year RCx $ Savings $500,000 $450,000 $400,000 $350,000 $300,000 $250,000 $200,000 $150,000 $_saved (therm) $_saved (kwh) $100,000 $50,000 $- $(50,000) Library HQ Bellflower Beverly Hills Compton Downey East LA Rio Hondo Malibu CC Santa Monica San Fern Whittier Total Figure 21: Post-RCx operational savings ($). 14
RCx kwh Savings Against Baseline RCx kwh Savings 2,500,000 2,000,000 1,500,000 1,000,000 500,000 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2006 kwh 3yr avg 02-04 Figure 22: Post-RCx electric energy (kwh) savings. 15
RCx Therm Savings Against Baseline RCx Therm Savings 80000 70000 60000 50000 40000 30000 20000 10000 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2006 Therms-3 yr avg 02-04 Figure 23: Post-RCx gas energy (therms) savings. 16
Post-RCx kwh EUI Post-RCx-EUI (kwh/gsf/yr) 25.0 20.0 15.0 EUI (kwh) 10.0 5.0 0.0-5.0 Library HQ Downey CH BeverlyHi llsch EastLAC H WhittierC H MalibuC C ElMonte CH Bellflowe rch SanFern andoch SantaMo nicach Avg_meas_EUI_Sav 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 kwh_eui_bill_sav 6.0 4.6 5.0 0.9 1.9 2.2 2.9 3.7 1.0-0.7-0.2 PostRCx_Meas_kWh_EUI 17.0 15.4 14.0 18.1 16.1 13.8 12.1 9.3 12.0 11.7 10.2 PreRCx-kWh_EUI 23 20 19 19 18 16 15 13 13 11 10 Compton CH Figure 24: Post-RCx EUI (kwh). 17
The EEMIS Network is a Collection of Discrete Systems 18
L A County EEMIS Network Figure 4: County of Los Angeles Enterprise Energy Management Information System (EEMIS) configuration. 19
RCx Sustainability Process Figure 3: Three-prong approach for persistence of RCx savings. 20
Verification of Fan Operation Figure 5: Weekly Fan Operation 21
Verify Chiller Schedule Saturday operation Figure 11: Chiller Operating Schedule. 22
Chiller OSAT Lock-out Chiller delayed start after OSAT 60 F Figure 12: Chiller lock-out temperature verification. 23
HWP OSAT Lock-out HWP dropping off at 70 OSAT Figure 15: Hot water pump OSA lock-out. 24
HWST Reset OSAT peak and Hot Water Supply Temp valley Figure 14: Verification of HWST reset based on OSAT 25
Verify Cold Deck Reset Figure 8: Supply air vs. return air temperature. 26
Hot Deck Reset OSAT peak and Hot Deck temp valley Figure 10: Hot deck temperature vs. outside supply air temperature. 27
Whole Building Energy, Demand Demand monitoring of whole building utility Weekday Weekends Night kwh Performance - Cumulative Monthly Annually 28
Utility Main Figure 16: Building Demand (kw). 29
System-level Benchmarking EEMIS UCE+ Figure 20: RCx persistence process utilizing Universal Calculation Engine Plus (UCE+). 30
equest Output Bin Data 31
System Level Benchmark Chiller kw Vs. OAT 32
Cooling (Tons) 800.00 700.00 600.00 500.00 400.00 300.00 200.00 100.00 equest Model Tonnage MTC Cooling vs OSAT y=0.0157x 3-3.7977x 2 +315.38x- 8647.4 R 2 =0.8524 0.00 60 70 80 90 100 110 Outside Air Temperature 33
equest Model for Gas MTC Post RCx Cummulative Natural Gas Consumption Natural Gas Consumption (Therms) 60,000 50,000 40,000 30,000 20,000 10,000 0 y = 85.868x 3-1888.8x 2 + 15405x - 7293.4 R 2 = 0.9832 1 2 3 4 5 6 7 8 9 10 11 12 Month of the Year (1-12) 34
Optimized equest Output 35
equest vs Actual - kwh 36
Heating (Therms) Traffic Courts Heating Profile MTCHeating vs OSAT y=-0.0025x 3 +0.4056x 2-22.742x+463.03 70 R 2 =0.7658 60 50 40 30 20 10 0 30 35 40 45 50 55 60 65 70 Outside Air Temperature 37
Recap: HVAC Retro-commissioning and EEMIS Monitoring HVAC Retro-commissioning Investigate and resolve operational deficiencies Install and test Energy Efficiency Measures Develop system-level benchmarks Three-prong approach to sustain RCx savings Facility monitoring Utility bill analysis with whole building benchmarks System-level benchmarks to detect deviations 38
Partnership Credits Southern California Edison Michael Lo, Program Manager Southern California Gas Co. Paulo Morais, Project Manager County of Los Angeles Internal Services Dept. Howard Choy, Division Manager, ISD, Los Angeles County Nora Hernandez, Section Manager, ISD, Los Angeles County 39
Contact Information Brian Roberts County of Los Angeles Internal Services Department T: 323-267-3010, E: broberts@isd.lacounty.gov N. Amar Amarnani County of Los Angeles Internal Services Department T: 323-267-2441, E: namarnani@isd.lacounty.gov 40