Existing Building Energy Saving Ir Cary Chan Executive Director, - - PowerPoint PPT Presentation

Existing Building Energy Saving

Ir Cary Chan

Executive Director, HK Green Building Council

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Aviation industry

1903 1930s 1969 1981 1971

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A big gap to fill

Convincing responses to your boss ! Deliver !

E nergy Management Process

Implementation of energy management

DATABASE POLICY OBJECTIVE & TARGET ACTION PLAN AUDIT MEASUREMENT & VERIFICATION REVIEW MEETING & REPORT ANALYSIS

ACT PLAN

IMPLEMENTATION

DO CHE CK

Knowledge-based DIAGNOSIS (Retro-Cx) BENCHMARKING

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Design parameters Load calculation System design Equipment selection T esting and commissioning

Idea of ACT

• Shop
• Groups of representatives from buildings going through a retro-commissioning process
• Buildings as living laboratories
• HKGBC as facilitator
• Learning from peers
• Building up knowledge

Together

In participating in the ACT

• Shop programme :
• Actively supporting HK gov’s energy saving plan
• Building up the competence for the industry on retro-

commissioning through

• developing the data/knowledge base
• developing a systematic approach for retro-commissioning
• demonstrating the value of retro-commissioning
• transferring the knowledge and skills to the industry
• establishing a practical operation & management system
• Promoting the adoption of best practices to the

industry

Initial findings

Different types of building, system design , age..

Bldg A Bldg B Bldg C Bldg D Bldg E Type Composite Hotel Composite (Podium+ T

• wers)

Composite (Office +Education) Office (Industrial Building Renovation) Age (Yrs) 25 41 24 20 20 IFA (sqm) ~20,000 ~36,000 ~150,000 ~4,500 ~45,000 Chiller 4x320TR Water-Cooled (new) 4x180TR Water-cooled 4x190TR Air-cooled (new) 7x1000TR Water-cooled 2x400TR Water-cooled(Night) 1x150TR Air-cooled 1x150TR Air-cooled (new) 4x400TR Air-cooled Cooling T

• wer

4 4 6+2 N/A N/A Control Differential Pressure Bypass Differential Pressure Bypass Differential Pressure Bypass Differential Pressure Bypass Differential Pressure Bypass Pumps 4+1 Water-cooled: 4 Air-cooled: 4+1 7+2 4+2 (Office T

• wer)

2+1 4+1 Features Variable Speed Chiller 140TR Heat Pump for hot water Heat Exchanger for high rise office tower natural ventilation allowed Fresh air treated by FCU

．

Availability of data and information varies !

Approach a and Met etho hod

Has to consider :

• Practicality
• Minimum provision of instrument
• Availability of data and information

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“ACT

• Shop” – Data Analysis Method

(retro-Cx)

2.

Performance line evaluation

3.

Peak demand shedding

Outdoor Ambient Temperature Loading Valve Authority 24:00 Peak Demand 0:00

summer winter

Control Set-point

Re-tune:

• Discharge valve
• Double regulating

valve, etc.

Cooling Load %load

100%

Re-tune: 1. DTCHWS 2. DTA 3. DSP

2 3

1.1 1.2 1.3

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Outdoor Ambient Temperature Cooling load

4. Set-point reset 1. Re-tune

1.1 Valve authority 1.2 Set-point 1.3 Equipment operation

4. DPWS 5. TAPP

,C

6. TAPP

,C T

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““ACT

• Shop” – Data Analysis Method

(retro-Cx)

Bldg A Bldg B Bldg C Bldg D Bldg E

DTCHWsummer DTCHWwinter 5.0°C 2.5°C 5.0°C 3.2°C 5.0°C 3.0°C 2.5°C 0.75°C 3.4°C 2.0°C TCHWSsummer TCHWSwinter 7.8°C 10°C 7°C 11°C 8°C 9.5°C 9.5°C 14°C 8.5°C 10°C COP,CHsummer COP,Chwinter 6.3 13 3.3 3.4 5.3 4.2 3.2 2.9 1.6 2.5 EUI(Chiller) 60 kWh/m2/year 115 kWh/m2/year 88 kWh/m2/year 33 kWh/m2/year 48.3 kWh/m2/year

Low CO P Low DTCH W TCHWS reset at winter

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• 1. Re-tune – Chiller Operation

Cooling Load/m2

Percentage of Full Load Ampere (%FLA) 3 Chillers Zone 2 Chillers Zone 1 Chiller Zone 100% Full Load

• Good operation
• Poor operation (high % full load ampere due to deterioration of chiller

capacity)

More FLA Less FLA Extra chiller

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• 1. Re-tune – Chiller operation (cont’d)

% Full Load Ampere issue

0% 20% 40% 60% 80% 100% 20 40 60 80 100 120

Percentage of Full Load Amp Cooling Load Intensity

Bldg C

1 Chiller 2 Chiller 3 Chiller 4 Chiller 5 Chiller 0% 20% 40% 60% 80% 100% 20 40 60 80 100 120

Percentage of Full Load Amp Cooling Load Intensity

Bldg E

1 Chiller 2 Chiller 3 Chiller 4 Chiller

Extra chiller in operation Chiller

• perate at

high % FLA

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• 1. Re-tune – Chiller Operation (cont’d)

Delta T of Chilled Water issue

Delta T of Chilled Water 3 Chillers Zone 2 Chillers Zone 1 Chiller Zone Delta T of Chilled Water Design Value Cooling Load/m2

• Good operation
• Poor operation (narrow delta T due to excessive flow

through chillers or bypass pipe)

Large Delta -T Small Delta-T

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• 1. Re-tune – Chiller Operation (cont’d)

Delta T of Chilled Water issue

0.0 1.0 2.0 3.0 4.0 5.0 6.0 20 40 60 80 100

Delta T of Chilled Water (°C) Cooling Load Intensity

Bldg B

1 WCC 0.5ACC + 0.5WCC

One chiller capacity but two pumps

0.0 1.0 2.0 3.0 4.0 5.0 6.0 20 40 60 80 100 120

Delta T of Chilled Water (°C) Cooling Load Intensity

Bldg E

1 Chiller 2 Chiller 3 Chiller 4 Chiller

Extra flow through chiller

0.0 1.0 2.0 3.0 4.0 5.0 6.0 20 40 60 80 100 120

Delta T of Chilled Water (°C) Cooling Load Intensity

Bldg C

1 Chiller 2 Chiller 3 Chiller 4 Chiller 5 Chiller

Extra flow through bypass pipe

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• 1. Re-tune – Chiller Operation (cont’d)

%Bypass Flow issue

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• 1. Re-tune – Chiller Operation (cont’d)

%Bypass Flow issue

0% 50% 100% 150% 200% 250% 20 40 60 80 100 120

Percentage of Bypass Flow Rate Cooling Load Intensity

Bldg C

1 Chiller 2 Chiller 3 Chiller 4 Chiller 5 Chiller

Extra flow through bypass pipe

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• 2. Performance line evaluation

Using thermal & electricity performance line

Consumption/Load Intensity Outdoor T emperature COP keeps constant Consumption/Load Intensity Outdoor T emperature COP increases at part load Consumption/Load Intensity Outdoor T emperature COP decreases at part load

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• 2. Performance line evaluation (cont’d)

Using Coefficient of Performance line

Cooling Load Intensity Coefficient of Performance (COP) COP = constant

• 2. Performance line evaluation (cont’d)

VSD Water-cooled 5 10 15 20 40 60 80 100 120 COP Cooling Load Intensity

Bldg A

CSD Water-cooled

• 1

4 9 14 20 40 60 80 100 120 COP Cooling Load Intensity

Bldg C

CSD Air-cooled 2 4 6 8 10 12 14 20 40 60 80 100 120 COP Cooling Load Intensity

Bldg E

Note: Not sufficient data for Building B (No COP data),

CSD Air-cooled

• 1

4 9 14 20 40 60 80 100 120 COP Cooling Load Intensity

Bldg D

new chiller Old Chiller VSD Air-cooled

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• 1. Summary of Common Problems
• n Chiller Plant Systems

Common Problems on Chiller Plant Systems Bld A Bld B Bld C Bld D Bld E Chillers Improper chiller sequencing  *    Serious chiller deterioration   Pumps (chilled water flow) Low/improper bypass valve setting      Deviation on chilled water flow rates across each chiller  Primary variable flow design but not fully in

• peration

 N/A N/A N/A  Cooling towers High approach temp  N/A N/A

*One chiller is sufficient to provide cooling over a year

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• 1. Summary of Re-tuning Work

Suggested Re-tuning Work Bld A Bld B Bld C Bld D Bld E Chillers Reduce chiller operation (N-1) to achieve higher

• verall COP



*1



*2

 Increase Tcws  

*2



• Max. demand shedding

     Pumps (chilled water flow) Re-tune bypass valve setting    Install differential pressure sensors at the critical path   Install VSD on the existing chilled water pumps N/A  

*2

N/A Cooling towers Reactive cooling tower (CT) optimisation N/A N/A  N/A 

*1 One chiller is sufficient to provide cooling over a year *2 Serious chiller deterioration  limited improvement

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• 1. Saving Summary of Re-tuning Work

Suggested Re-tuning Work Bld A Bld B Bld C Bld D Bld E Chillers Reduce chiller operation (N-1) to achieve higher

• verall COP

5-6% (Actual)

*1

3-5% (Potential)

*2

3-5% (Potential)

Increase Tcws

1-3% (Potential) 1-3% (Potential)

*2

1-3% (Potential)

• Max. demand shedding

0-1% (Potential) 1-3% (Potential) 0-1% (Potential) 1-2% (Potential) 0-1% (Potential)

Pumps (chilled water flow) Re-tune bypass valve setting

1-3% (Potential) 1-3% (Potential) 1-3% (Potential)

Install differential pressure sensors at the critical path

1-3% (Potential) 1-3% (Potential)

Install VSD on the existing chilled water pumps

N/A 3-5% (Potential) 3-5% (Potential)

*2

N/A

Cooling towers Reactive cooling tower (CT) optimisation

N/A N/A

1-3% (Potential)

N/A

1-3% (Potential)

*1 One chiller is sufficient to provide cooling over a year *2 Serious chiller deterioration  limited improvement

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• 1. Payback Summary of Re-tuning Work

Suggested Re-tuning Work Bld A Bld B Bld C Bld D Bld E Chillers Reduce chiller operation (N-1) to achieve higher

• verall COP

<1 year *1 3-5 year *2 <1 year

Increase Tcws

<1 year <1 year *2 <1 year

• Max. demand shedding

<1 year <1 year <1 year <1 year <1 year

Pumps (chilled water flow) Re-tune bypass valve setting

<1 year <1 year <1 year

Install differential pressure sensors at the critical path

<1 year <1 year

Install VSD on the existing chilled water pumps

N/A 3-5 year 3-5 year *2 N/A

Cooling towers Reactive cooling tower (CT) optimisation

N/A N/A <1 year N/A <1 year

*1 One chiller is sufficient to provide cooling over a year *2 Serious chiller deterioration  limited improvement

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make the most out of the next Energy Audit

Review and identify improvements needed from last audit : Quality of measurement , methodology , robustness of data , value of data, readiness of building operators and REA..etc Learn where to focus Setting a foundation for the future : New requirements for data and information for future management, tracking and analysis ( for buildings, industry and government) Useful O&M manual Benchmarking Building capacity ( building provisions, knowledge , specially trained REA.. ) Central data center Setting up energy management systems

Performance Assessment Development of KPI (Air conditioning)

Performance Assessment - KPI benchmarking

Performance Assessment -KPI benchmarking

Performance Assessment - KPI benchmarking

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Case Study: Problem in Air Handling Unit

Always open Always close

Diagno nosi sis

Are our systems working?

Hotels New Development Commercial Bldgs

Existing Bldg A 145 136 (50th%) 2011 2016

How do we compare with others?

Opportunities

Benchma marki king ng

Long T g Term P Planni nning ng

Can we have a 10-year plan?

Saving = 9,858kWh/year Saving Estimation

ANAL YSIS

How much can you save?

Knowledge-Based Energy Management

Sensors

Analysis Useful Information Utilise Information

• Facilitate Research
• Implement Initiatives

Data Transmission

Data Bank BMS

Always close

Saving E g E stim imat atio ion M&V &V M Met ethod

• d

Fau ault lt D Diag iagnosis Long T Term P Planni nning ng Oppor

• rtunities

es

Characteristic

Sources: Swire Properties Ltd

Action Research

Difficulties

Lack of market drives

• Not aware benefit
• f using data

Software not user friendly

• Proprietary product

High investment

• Cost not directly

justified

• Product upgrade
• Staff training

Data missing

• Massive data

transmission and storage problem

Inaccurate data

• Sensor

malfunction/ improper location & error

Inconsistent data format

• Bldg. Mgt. Systems

& power metering systems not interoperable

Lack of support

• Not much demand

Inadequate hardware

• Power meter / Flow

meter / DP sensors

• n equipment/

system base

DATA F ACILITIE S BUSINE SS

Lack of Specification

• There is no any

requirement and standards for reference

ACT-shop

Knowledge - Why Operating Data Not Commonly Used?

Barriers

Collaboration issues within the Industry

Owner Designer Operator Contractor

• Inadequate drives for knowledge

based management

• Focus on project cost only
• Lacks BMS/PMS/DMS expertise
• Lacks O&M experiences
• Shortage of construction time
• Inadequate T&C and re-commissioning

concept

• Focus on services reliability for tenants
• Lack of interest and capabilities in

performance analysis

Manufacturer

• Focus on functional operation needs only
• Value of information management not

emphasis

• Lacks of interest in O&M market
• Emphasis on cost competitiveness

ACT-shop

Output Input Efficiency =

Key Performance Indicators

DATA  INFORMATION

How Efficient is Our Plant?

BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS

Quality of Data

• Accuracy
• Right Form
• Accessibility

Problems:

• Missing data
• Incorrect form of data
• Huge data volume and scale
• Incompetence in analysis

Technical Challenges

Run to Life Retrofit Knowledge transfer Early Replacement House keeping General Practices & Regulatory Compliance Optimization

Continuous Improvement

Chiller Lighting Advanced Control Air-cool  Water-cool Lift Modernization Retro-Cx Metering Work with stakeholders Routine Inspection

Knowledge-Based Practice

Adopt Best Practice

Maintenance Requirement

Routine Maintenance Mandatory Audit O&M Manual

Basic Need

Saving ~17% Saving >24%

Transformation of the Current Industry

Building Operator

• Government
• Private Sector

Services Provider

In-house Competence e-O&M Manual Develop & drive the products / services markets Saving Business knowledge Beyond Standard

• Detailed databank
• Develop competence within the

industry

• Standardise energy analysing

method / format

• Raise next energy audit standard
• Robust benchmarking system

Industry

HKIE BSOMES ASHRAE RICS…

Education

VTC/IVE Universities

ACT SHOP

Establish Knowledge Sharing Platform

Analysis & Benchmarking (Opportunities?)

• Fault detection

How Data Helps

• Time series analysis
• Expert rules

Tool

Diagnosis (Any fault?)

• Fault detection

How Data Helps

• Time series analysis
• Expert rules

Tool

Case Study: Problem in Air Handling Unit

Case Study: Problem in Air Handling Unit

Problem Verification

Case Study: Problem in Air Handling Unit

After problem solving

Re-tune (Implementation)

• Optimise operation

How Data Helps

• Engineering

Approach

Tool

ΔT

ΔT , design = 5°C Data of ΔT high condensing differential temperature

Design Real Operation

Underflow 7°C

Any Deviation?

Entering Cooling Tower Cooling Tower To BMS

P P

Flow con

collector collector

1m

Leaving Entering Cooling Tower Cooling Tower To BMS

P P

Flow con

collector collector

1m

Leaving Leaving

T T

to remove the flow-con:

• higher water flow rate
• lower condensation temperature
• higher chiller efficiency

Underflow Increase pressure Reduce resistance

More consumption

lower 7°C 4.5°C

Problem Identification & Rectification

kPa

Riser iser A B C D E F Criti ritica cal A l AHU 33.5 35.2 37.4 37.8 35.5 35.8 Targe arget 54 56 57 58 56 56

ΔP ΔP ΔP ΔP ΔP ΔP

Return Supply

Riser A Riser B Riser C Riser D Riser E Riser F

Design Real Operation Vs.

Any Deviation?

Restricted by under-sized AUHs Renovation of under- sized AUHs A B C D E F

Original

85 110 95 95 100 100 Step 1 85 110 90 90 100 100 Step 2 75 110 80 80 80 80 Step 3 70 80 70 70 70 70

Summer time exercise Winter time ??

∆P reset

Over pressurized

Problem Identification & verification

• Saving Estimation

How Data Helps

• Regression model +

BIN Method

Tool

Saving Estimation, Measurement & Verification “Conversion from IGV to VSD control”

Retrofit – Saving Estimation

Retrofit – Measurement & Verification

Manufacturer claimed saving cannot be identified Performance indicator to be verified against % loading at particular range of impact factor(s)

Energy Management – Long term Plan

(Are we achieving our target?)

• Energy management

reporting

How Data Helps

• Cumulative frequency plot

Tool

Buildings in HK account for:

90% Total Electricity Consumption

60% Greenhouse Gas Emission

Existing Buildings account for

90% of HK Building Stock

Achievement and Target

Cost and Benefit

Database

Measurement and Verification

Condition 1 Condition 2 Condition 3

Did it work?