2017 NEHES Fall Conference Technical Breakout Session: Deep Chiller Plant Optimization

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1 2017 NEHES Fall Conference Technical Breakout Session: Deep Chiller Plant Optimization Presented by: Steve Keppler, Senior Director Critical Systems Design Build Practice CLEAResult

2 Deep Optimization Standard Optimization Chiller Plant Optimization Progression Annualized System* kw/ton Starting State: Traditional Plant Design-Standard Control Equipment Upgrade: High Efficiency Prime Movers Control Optimization: Host BMS or Web Overlay Deep Optimization Tipping Point Economization: Integrated Waterside Economization and SOO Pumping System Optimization-Terminal Systems RCx-SOOs * chiller(s), tower(s), pumps all in kw

3 Triggers/Opportunities to Begin Plant Optimization Plant approaching capacity or redundancy limits/challenges Planning significant load increases Plant major equipment end of life Operational/maintenance problems where replacement is CapEx planned Distributed, multiple, noninterconnected plant capacity and adding a wing or new building Facilities/Functional Plant capacity is localized with chillers and towers headered together At least one chiller has a VFD Plant has an in-operable WES HX Operating multiple loops at varying supply temperatures Stable and reliable plant operations challenged by control or automation system problems or limitations Copyright 2013 CLEAResult. All rights reserved. 3

4 Triggers/Opportunities to Begin Plant Optimization Corporate Published sustainability and/or corporate responsibility goals and objectives/plans Upcoming mergers or JCOH re-accreditation (reliability) Downward pressure to maintain revenue by managed care rule profit erosion (via operations cost reductions) Focus and need to improve patient care ratings to maximize managed care potential capture (care giver and system investments needed) Patient and community perception Copyright 2013 CLEAResult. All rights reserved. 4

5 Standard Optimization Strategies Plant Chiller Replacements High efficiency Integrated VFDs Load match deployment Tower replacements High efficiency VFDs Low approach temps Pumping EE motors VFDs Controls Technology refresh Cloud overlay Peripheral expansion Flow-Temps-Energy Deep Trending Host or Cloud Sequence Optimization Incumbent system SOO redesign Operating temperature and flow tuning Staging strategies Copyright 2013 CLEAResult. All rights reserved. 5

6 Deep Optimization Strategies & Timings Free Cooling System Design Changes 1. Plant level free cooling Waterside economization Air cooled chiller economization 2. Terminal level free cooling RCx of firm wear- dampers Plant configuration changes Chiller headering Tower headering Waterside economizer Pumping system redesigns Primary > Primary/Secondary Primary/Secondary > Variable Primary Incumbent system SOO redesign Copyright 2013 CLEAResult. All rights reserved. 6

7 7 Air-Cooled Chiller Economization Strategies Add WSE to Air Cooled CW loop HX and small tower with series design Add-on evaporative cooling enhancement systems to existing air cooled chillers Replace EOL air cooled chillers with new air cooled chillers with integrated refrigerant economizers Replace EOL air cooled chillers with new air cooled chillers with integrated water economizers

8 Water Side Economizer: Traditional Parallel Design Cooling Tower Water-cooled Chiller Load Heat Exchanger (HX) Provides good energy savings based on allowable water supply temperature Provides free cooling when cooling tower can supply up to F Transitioning between chiller and heat exchanger is problematic No partial free cooling (No sharing of load between HX and Chiller) Reduced hours of economization hours (when WB is less than 50 F)

9 Water Side Economizer: Integrated Series Design (IWSE)* *ASHRAE WSE Standard Cooling Tower Heat Exchanger (HX) Water-cooled Chiller Load HX Bypass Heat exchanger and chiller share the load Provides partial economization in shoulder WB hours Reduces chiller operation and eliminates switch over complications Increased economization hours = Significantly increased energy savings SSO redesign critical success factor RG Loop IWSE design patent pending

10 Denver Seattle Albuquerque Hillsboro San Jose Salt Lake City Boston Los Angeles Las Vegas Sacramento Chicago Newark Phoenix Washington Riverside Kansas City Oklahoma City Dallas Austin San Antonio Houston % of time IWSE Engineered Performance 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Time in Cooling Mode The performance of a traditional parallel WSE HX design is the free cooling only % of operating time. Mech. Cooling FG Partial LoopCooling Free Cooling RG Loop IWSE design patent pending

11 1 North East Energy Consumption Example (1000 ton load) Chilled Water Setpoint 45 F CLEAResult Proposed Chiller Plant - Annual Energy Performance Cooling Mode WB Range ( F) Op.Hrs/Yr Chiller Plant (Avg. kw/ton) Chiller Load (Ton-hrs) Chiller Plant (Avg. kw) Consumption (kwh) ByPass > 54 F 2, ,110, ,146,873 Pre-cooling 40 F > and <= 54 F 2, ,387, ,535 Free <= 40 F 4, ,263, ,037 Total: 8, ,760, ,518,445 Chilled Water Setpoint 55 F CLEAResult Proposed Chiller Plant - Annual Energy Performance Cooling Mode WB Range ( F) Op.Hrs/Yr Chiller Plant (Avg. kw/ton) Chiller Load (Ton-hrs) Chiller Plant (Avg. kw) Consumption (kwh) ByPass > 64 F , ,951 Pre-cooling 50 F > and <= 64 F 2, ,898, ,632 Free <= 50 F 5, ,811, ,552 Total: 8, ,760, ,649,135

12 12 Case Study: SE Regional Hospital Chiller Plant Electrical Demand (kw) 1 Msf, 3 building, 750 bed, 4000 ton/2100 bhp central plant, 76 AHUs Baseline Performance Post Performance $450,000 annual savings 5.5 mwh - 161,000 therms 1.3 kw/ton >> 0.5 kw/ton 60% cooling plant annualized performance improvement Outdoor Wetbulb Temperature ( F) SCOPE New 1500 ton chiller/1500 IWSE New 1500 ton low approach tower CV to VF flow pumping CV to VF AHU retrofit Plant and AHU control SOO redesign AHU RCx Lighting and radiant heating retrofit

13 CHILLER PLANT (KW/TON) 13 Case Study: NE 600 Ton Load Data Center CLEAResult R-G Loop Chiller Plant Performance-Waltham, MA SCOPE Remove 4 EOL AC Chillers Replace 3 new AC +1 chillers New 750 ton chiller/iwes CIB New low approach tower VF pumping and plant SOO redesign Existing Performance (kw/ton) Full CRAH SOO redesign Outdoor Wet Bulb Temperature ( F)

14 Plant Load (Tons or KW) Efficiency (kw/ton) 14 Case Study: 600 Ton Load NE Data Center IWES Plant Plant Load and Efficiency Average of PLANT TONS Average of TOTAL KW Average of KW/TON

15 Chiller Plant Performance (kw/ton) 15 Case Study: Silicon Valley Data Lab Projects 5 buildings on concurrent schedule Baseline Outdoor Wetbulb ( F) Post-M&V Performance Baseline Performance Full Cooling Predicted Performance Partial Free Cooling SCOPE IWSE integration to existing 3 chiller, 1000 ton plant and existing towers Primary/secondary to variable primary pumping retrofit Full plant, tower, IWSE, pumping control SOO redesign Controls software upgrade.

16 16 Silicon Valley Data Center Projects Performance RESULTS: $1.1M annual savings $1.2M utility incentive 10.5MkWh annual reduction 3 year simple payback.45 kw/ton annualized 41% cooling reduction Bldg. A IWSE-Pumping Retrofit-Controls Upgrade Bldg. B Bldg. C Bldg. D Bldg. E

17 Questions & Discussion Some case study examples presented were hot tap implemented, with little or no system shutdown required for implementation, accomplished with team approach, detailed planning, and our favorite helper technology, the line stop. watch?v=aypacknnz6q) Steve Keppler CLEAResult Senior Director Critical Systems Design Build Practice c(301)