HVAC CONTROL

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ASHRAE National Capitol Chapter - PES Wednesday, Nov 7, 2011

Central Plant Optimization

Dave Klee, LEED AP

Director, Optimized Building Solutions Johnson Controls, Inc.

http://www.johnsoncontrols.com/cpo

where we are,

where we could be,

how we can get there.

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The Case for Central Plant Optimization

HVAC provides the largest energy savings opportunity

The Case for Central Plant Optimization

Within the HVAC system, Chiller plants provide the greatest energy savings opportunity. Within the chiller plant, the chiller provides the greatest opportunity.

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To maximize efficiency, plants must be designed and operated holistically

Pumps & Motors

Variable Speed Drives

Efficient and capable components can get you only so far. We must optimize at a system level.

Cooling Towers Chillers

Automation & Optimization

Meet the load with minimum power How optimization works

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7 REDUCE: Chiller Energy Pump Energy System Energy Steam Energy Water Use Intelligent algorithms are

required to optimally vary:

Chilled water temps flow Condenser water temps flow simultaneously without hunting

Meet the load with minimum power Simultaneously, without hunting

Measuring plant efficiency How do plants measure up?

Average annual plant efficiency in kW/ton for chilled water plants includes total power consumption from chillers, all pumps and tower fans

Legacy Chiller Plants Conventional Plants Efficient Plants Highly Efficient VSD Plants

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Measuring plant efficiency:

A real-world example of what’s possible

Month Ton-hrs Old kWh Old

kW/ton Optimized kW/ton Savings Nov-09 395,395 395,241 1.00 0.66 134,280 Dec-09 259,478 331,592 1.28 0.68 155,147 Jan-10 231,408 299,829 1.30 0.78 119,330 Feb-10 242,092 309,528 1.28 0.60 164,272 Mar-10 185,457 213,358 1.15 0.52 116,724 Apr-10 351,837 353,650 1.01 0.55 160,140 May-10 530,402 497,365 0.94 0.51 226,860 Jun-10 784,549 526,061 0.67 0.55 94,559 Jul-10 833,703 643,522 0.77 0.58 159,974 Aug-10 789,405 602,121 0.76 0.60 128,478 Sep-10 780,230 658,974 0.84 0.62 175,231 Oct-10 613,859 581,472 0.95 0.62 200,880 Annual Totals 5,997,816 5,412,712 0.90 0.60 1,835,875

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Automate System

Apply components effectively, optimally

Select components effectively, optimally

Design system infrastructure to max efficiency potential

Design Decisions

Is your design ready for optimization?

Optimization starts with a firm design foundation

Automate System

Automation Optimization

Prerequisite Opportunity Sequences Algorithms The order of events The optimal events

Executes Advises

Holds setpoints Calculates optimal states, speeds, setpoints Meets the load Meets the load

with minimum power Today’s standard Tomorrow’s standard

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Automate System

Optimization starts with a firm design foundation

New construction:

Plant infrastructure, components instrumentation and automation are

designed such that when optimization software is applied, its performance is maximized and sustained.

Existing buildings:

Plant infrastructure, components, instrumentation and automation are

upgradedsuch that when optimization software is applied, its performance is maximized and sustained.

What is Optimization ReadyTM_?

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Measure & Verify

Optimize System

Automate System

Operating Decisions

Maintain

Optimization is a process.

Not a one-time event. Not just software. Not a bill of materials.

1. Correct System Deficiencies 2,3. Correct Equipment Deficiencies 4. Automate with Proven Algorithms 5. Add Optimization Software 6. Measure, Verify & Manage 7. Maintain Address pre-existing conditions

1. Design Efficient System 2,3. Select & Apply Equipment Effectively 4. Automate with Proven Algorithms 5. Add Optimization Software 6. Measure, Verify & Manage 7. Maintain Existing Buildings New Construction

Start with Sound Design Decisions

Optimization works in New Construction and Existing Buildings: Design or retrofit to get to optimization ready. Then optimize.

Optimize Optimize

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Read the whitepaper: http://www.johnsoncontrols.com/cpo

Measure & Verify

Optimize System

Automate System

Operating Decisions Design Decisions Maintain Measure & Verify Optimize System Automate System

Operating Decisions

Maintain

Know our enemies.

“We can do that!” “It’s not working!”

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Maximize your potential.

1. Design efficient

system infrastructure

Which system configuration is most likely to deliver the most efficient plant?

Chilled Water System

Headered Dedicated Variable Primary A B

Primary / Secondary C D

Constant Primary E F Condenser Water System

Headered Dedicated

Variable Flow 1 2

Constant Flow 3 4

Step 1:

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Headered Dedicated

Variable Primary B

Headered Dedicated

Variable Flow 1 2

Constant Flow 3 4

Step 1:

Design efficient system infrastructure

Headered Dedicated

Variable Primary B

Headered Dedicated

Variable Flow 2

Constant Flow 3 4

Step 1:

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Steps 2&3: Once you have efficient system design, Evaluate & select components on a real-world basis

Step 5: Central Plant Optimization

Some characteristics are nearly universal

The load is met.

Comfort and safety not impacted

Whole-system approach (chillers, pumps & towers)

All-VSD plants best performance

Effective BAS is in place; capable of control and data gathering

Standardized solution (not one-off, custom)

Adjustments are made automatically

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The nature & basis of algorithms will vary

How are optimization decisions made?

Some focus on primarily on pumps

Proven best-in-class practices

Equipment efficiency curves

Energy-based sequencing

Proportional/ integral/ derivative

Adaptive tuning loops

PID loops

Relational control

Transparent or proprietary

The solution architecture will vary

Where do the algorithms reside?

Inherent in the BAS

Add-on appliance (usually on site) Where does the data flow?

Within the BAS

BAS server collects data

BAS server “serves up” info to dashboard / reports

Within “the cloud”

Local appliance transmits

Remote server collects & “serves up” info to dashboard / reports Internet

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CPO: On-site Optimization Metasys or 3rd_{party BAS:}

Building Automation System

Chillers

VSDs on pumps, cooling tower fans

Sensors, Meters & Controlled Devices Customer Service Center MVM: Measurement, Verification and Management Customer site Client Desktop Central Plant Optimization

Solution Architecture Example

Internet Internet

Reliability – structured commissioning process

Stability – Stable operation and persistent performance

Repeatability – not reliant on individuals’ expertise

Predictability – performance is understood, proven

Visibility – measurement, verification and management Step 5: Central Plant Optimization

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Step 6: Measure, Verify & Manage performance

Actionable information to empower sustained performance

Web-based UI for remote access Remote monitoring and diagnostics Real-time trends; Periodic reports Alert notification & escalation UI representing actual plant layout Actionable info, tailored to users’ needs. Long-term data storage and management

Energy consumption & cost Weather data and load profiles Equipment runtime, starts, stops

Step 6: Measure, Verify & Manage performance

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Run to fail

Repairs to equipment not included in plan

Necessary repairs made reactively upon failure

Scheduled maintenance

Focus on component care

Performed regularly

Predictive Services

Strategy focus uptime and performance

Proactive management

Elimination of equipment failure

Step 7: Maintain

Sustain the value of the investment in optimization

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Optimization Case Study:

Cleveland State University

Situation

• 3,800,000 sq. ft. campus in Cleveland, OH • Most load is 7am to 10pm, but laboratory and

student housing load is 24/7.

Solution

• Two 2,750-ton, one 1,000-ton Yorks; Two 1,000-ton Tranes. All Metasys.

• Implemented OptimumHVAC / CPO 30

Result

• Est. energy use savings: 910,000 kWh/yr • Est. first year savings: $113,000

• To-date improved kW/ton: 36%

• Simple payback for the entire project: 2.7yrs

Optimization Case Study: University of Texas at Austin

Situation

District Cooling station serving 135 buildings (17 million sq ft )

Total campus load:145 million ton-hours / year

Rising energy prices, increasing cooling load

Solution

Replaced plant with a new, all-VSD plant

Installed 3 new 5000 ton York Titan chillers

Johnson Controls / OptimumLOOP

Result

Plant efficiency: 0.33 to .87 kW/ton , depending on wet bulb and campus load

Estimated first year savings: 5 million kWh

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Optimization Case Study: Sotheby’s Building

Situation

470,000 sq. ft. facility in New York City

Houses rare antiques & priceless art

Needed a reliable, efficient chiller plant

Solution

VSD retrofits on two 700-ton York centrifugal chillers, cooling tower fans, condenser water pumps and chilled water pumps.

Implemented Central Plant Optimization.

Result

Qualified for incentives: $167,000

Est. first year savings: $201,000

To-date improved kW/ton: 31.7%

Simple payback for the entire project: 3.6 yrs

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Large buildings / plants (>600T)

Multiple, centrifugal chillers

High loads (base & peak)

High operating hours (day/ wk/ yr.)

Data centers (or bldgs with them)

Process loads (served by plant)

Existing BAS (not manual control)

LEED or other green mandates

Funding for efficiency / expense reduction projects

Rebate programs, High utility rates

Johnson Controls CPO Ideal Targets for CPO

CPO is an Engineered, Financial Solution

Engineering & Implementation Process

Assess. Analyze. Design.

Implement. Save.

Optimization

Preliminary Assessment

Optimization

Analysis and Design

Optimization Architecture Proposal Optimization Implementation Optimization Continuous Commissioning Is the site a candidate for optimization? Financially? Technically? What are the design requirements for optimization?

What are the business requirements of the project to ensure success? Provides a comprehensive energy appraisal and an actionable plan that outlines the technical approach and business case for optimization. $ $ $$ $$ Phased approach that includes: • Mechanical upgrades • Controls integration • Network appliance

& software install • Testing and remote

commissioning Benefits: • Eliminates performance drift • Ensures optimum energy efficiency • Provides real-time plant analytics • Enables remote diagnostics

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www.johnsoncontrols.com/hvacdesign

www.johnsoncontrols.com/cpo

ASHRAE National Capitol Chapter - PES Wednesday, Nov 7, 2011