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PERFORMANCE INSPECTIONS WITH INNOVATIVE ANALYSING EQUIPMENT

RESULTS IN

SIGNIFICANT ENERGY SAVINGS

IN

AIR-CONDITIONING AND REFRIGERATION SYSTEMS

Klas Berglöf

ClimaCheck Sweden AB, Sweden

klas@climacheck.com

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Founded 2004 (method developed 1986)

Fast growing tripled turnover since 2009

More than 600 systems on the market

80% export

distributors in 15 Countries

5 markets dominating sales

UK, Italy, Spain, Sweden, Germany

Started introduction

Canada, USA and Australia

ClimaCheck Sweden AB

www.climacheck.com

ClimaCheck Sweden

Stockholm head office staff

Four engineers, one technician

Jönköping two engineers

ClimaCheck getting International acceptance

• Refrigeration Product of the Year 2009 in UK

• Member of Cleantech inn Sweden 2010

• World Wildlife Fund Climate Solver 2011

• In standardisation groups ASHRAE, Germany and UK

• Cooperation with 20+ universities and research institutes around

the world

• Awarded funding from Swedish Energy Agency Feb 2012

– 120 000 Euro - partner SP (=Swedish TÜV) develop guidelines/methods for SEI

• Awarded 203 000Euro Funding in EU Cool-Save project Feb 2012

– 1.3 million Euro total project (Efficiency in Food processing industry)

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Update - performance analysing

• Performance analysing – optimisation in HVAC in focus globally

• Standardisation Code of practice work in progress in many

markets

– UK – IOR – SEI “System Efficiency Index” under implementation

• ClimaCheck has standard system template incorporating SEI

– Germany – VDMA No. 24247 “Energy efficiency of cooling systems”

• ClimaCheck has standard system template incorporating VDMA 24247

– Sweden – Minimum requirement for Energy optimisation for HVAC

Logging and analysing equipment type ClimaCheck or equivalent

– USA – ASHRAE FDD SPC 207P “Fault Detection and Diagnosis”

ClimaCheck participate in standardisation workgroup

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ClimaCheck opens the ”Black Box” that often use 40-60% of a buildings electrical energy

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Establish base line – identify optimisation potential

Typical savings 10-40% from low cost measures

If there are compressors we are interested

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ClimaCheck Sweden AB Klas Berglöf

www.climacheck.com

Fixed installation Field inspection unit

Knowledge = enhance performance

save energy and environment

“If you cannot measure you cannot control it.”

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15-20% of all electricity used for refrigeration, air-conditioning and heat pumps

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13% of 164 systems were OK!

These were mainly commissioning or warranty inspections

planned and contractor had the chance to check

Huge difference between theory and practice!

Representation of faults for all the sectors

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51

78

4

2720

0102030405060708090

Com

press

or

Exp

ansio

n va

lve

Char

ge

Cont

rol s

yste

m

Sec

ondar

y flo

w

No fa

ults

Num

ber

of

syste

ms

Source: Master Thesis by John Arul Mike Prakash, , KTH Stockholm 2006

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Huge variation in COP

% Variation in COP (vs.) Nominal capacity kW

-40

-30

-20

-10

0

10

0 200 400 600 800 1000

Nominal capacity kW

% variatio

n in

CO

P

Source: Master Thesis by John Arul Mike Prakash, , KTH Stockholm 2006

Optimisation often saves

20-40% at minimal investment

Failure rate and cost

reduced

Carbon footprint higher than it should be

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Current situation and trend

• Equipment owner satisfied if temperature is achieved

• No requirement on documentation of performance

• Technicians-consultants have no chance to learn if they do not

have a customer requirement to do things.

• EU directive require “Performance Inspections” on all AC-

systems above 12 kW calculated to require 15 000 inspectors.

• Energy cost is increasing

• Environmental awareness - certifications

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Who is to blame?

• Equipment owners

– Buy on price and full-load performance

– Rarely validate actual operating performance

– Treat maintenance as a low cost commodity

• Manufacturer

– Supply what customers ask/pay for

– Servicemanuals lack most of relevant service

information

• Superheat, subcool, dT condenser/evaporator to air/water

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Who is to blame 2?

• Installers

– Do what customers pay them for

– Have no responsibility except warranty

– If nobody pay for optimisation it can not be supplied

• Service contractors

– Do what customers pay them for

– Difficult to make money on maintenance under competition

– Moneymaker is the failures – no price pressure

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Who is to blame 3?

• Universities and training institutes

Do not train researchers, engineers and

technicians that understand/focus on

operation of dynamic systems in real

applications

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Why the current situation?

• It has been considered to costly to measure cooling processes

in the field.

• Conventional method often raise more questions than it gives

answers.

• Equipment owners do not understand technology

• Purchasing process of buildings

• Owners short time perspective – buildings are built to be sold

• Commissioning procedures are mostly only “function test”

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Measuring and analysing the refrigeration cycle

• Analysing the refrigeration process offers:

– A cost-effective way to define actual performance

– A possibility to pin-point and quantify deviation

– Input to do cost/benefit estimates of improvements versus

replacements

– Change of focus from low cost maintenance to energy

optimisation

Upgrade of service industry

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When do you need Performance?

Commissioning – ensure spec. - minimize warranty cost

Performance inspection – optimisation

Continuous monitoring – early warning and optimisation

Preventive maintenance – reduce failure rate – optimise

Trouble shooting - FDD – avoid damage to product

Decision support – expansion – retrofit ?

Any expert - independent or from supplier can analyse system

Almost always needed!

visualisation of performance and function of each component

Also used by 40+ manufacturer development and production test rigs

Do not retrofit without knowing what you retrofit!

R-22 Retrofit Pre-retrofit analyses

Do not invest in poor systems that are failing

Post-retrofit analyses ClimaCheck optimisation

Fixed system Establish baseline

consumption

Optimise Document performance Detect future deviation

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Method is well proven

• Experience since 1986 when it was patented

• Method –evaluated - validated 1989 by SP – Technical Research Institute of Sweden

• 600 field measurement systems in use

• Used by 50 manufacturers of heat pumps, dehumidifiers, refrigeration and air conditioning equipment – Development laboratories

– Product control in production

– Commissioning, trouble shouting, warranty inspections and aftermarket

• Method used in research and education – Universities in Sweden, German, Spain, Italy, UK, US and several

“trade training institute”

Global references in all sectors

• Carrier Europe for Chiller optimisation performance inspections

– Use portable Performance Analysers in all EU countries for Inspections and trouble shooting.

• Supermarkets Sweden, UK, large project in Carrefour, Metro in Italy

– Saved 20-30% in pilot on 6 hypermarkets 2010 - now installed in 70+.

• Johnson Control industrial contractor in Spain/Sweden/UK

– Correct problems and improve efficiency in large industrial ammonia plants

• AC and heat pumps with leading companies such as i.e. Danfoss heat pumps

• Copeland Europe compressor manufacturers

– Use ClimaCheck in trouble shooting and development work with their customers

• DuPont and Solway refrigerant manufacturers

– Use ClimaCheck to document retrofit projects

• Several projects on-going in US, Australia, Middle East and India

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Easy to apply – to standard service “points”

2 pressures from service ports

Electrical input

7 surface temperatures

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Application of sensors to standard system (typically done in 20-30 minutes)

• 2 pressures

• 7 temperatures

• 1 power input

No information about system or compressor added

Simple Refrigeration Cycle

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P

h

m Vaporization

Expansion

condensation

compression

m

m m

m

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Analyzes on the “standard” process

Enthalpy

1. Low pressure and

suction temp.

2. High Pressure and

discharge Temp.

3. High pressure and

liquid temperature.

Mass Flow = (Power consumption – heat losses) / Enthalpy Increase

COP = Cooling Capacity / Power Energy Consumption

P LP

P HP

1

2 3

Ideal Compression

Cooling Capacity

Power Energy

Consumption

Heat Capacity

Enthalpy

Difference

Pressure

Use the Theory for practical use on field

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Theory Performance analysing using ”Black Box” perspective on compressor

Enthalpy increase refrigerant

Electric energy input

Heat losses

(relatively small and predictable)

(e.g. Electric input = enthalpy increase + heat losses from shell)

What about error in the heat loss estimate?

33kW

Conditions

+5/50°C R407C

T = +15°C

T = 85°C

Heat Loss Enthalpy Mass Flow Capacity

% Increase Rate kg/s kW

5 48.5 0.653 100

7 48.5 0.641 98.2

40% error in the Heat Loss results in <2% Capacity Error

Limitations

• If ”heat loss” from compressor can not be

modelled

– Oil-cooling normally easy to model

– Water-cooling is normally easy

– Air-cooling is normally easy

– Liquid injection can be a challenge

Remember that 99% of systems have no cooling

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Key Results

• Cooling capacity (± 7% accuracy) • Heating capacity (± 7% accuracy) • COP (± 5% accuracy) • Compressor efficiency • Super heat and sub cooling • Functionality of Control

• Evaporation, Condenser pressure and temperature • UA and mean temperature differences in evaporator and

condenser • Flow of secondary systems based on Capacity and temp.

difference

Listed are only key information – standard template consist of

> 40 outputs allowing detailed analyses of each component

Un-biased information on performance

1. The only input that is not a measured value is the heat

losses from the shell.

2. No manufacturer data as input

3. Documentation can be checked and evaluated by any

competent person

4. All components can be checked versus manufacturers data

Challenge is to build competence in industry

Awareness among users

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Report from Carrier site inspection

Rapport från mätning

Anläggning:

Datum: 20100426

Tidpunkt start: 11:57

Tidpunkt stopp: 13:17

Title

Measured

Value

Nominal

Data Deviation

COOL_EWT 9.5 °C 9.5 0.00 K

COOL_LWR 5.7 °C 5.7 0.00 K

COND_EWT 35.6 °C 35.6 0.00 K

COND_LWT 45.1 °C 45.1 0.00 K

POWER KW 350.2 kW 342.0 8.20 kW

COOLING CAPACITY 1177.4 kW 1160.0 17.40 kW

EER 3.36 3.39 0.03

HEATING CAPACITY 1503.2 kW 1484.0 19.20 kW

COP 4.29 4.41 0.12

Measurement made by:

Carrier Performance Analyser

ap 1.3 % positiv deviation

Stefan Orwén, Carrier AB, Malmö

TrioPlast, Landskrona KM11

Nominal data is the values we get from running E Cat with actual values from the measurement.

ap 2,8 % negativ deviation

Comment

ap 2,3 % negativ deviation

ap 1.5 % positiv deviation

Site:

Un-biased validation of

Performance – no Carrier inputs

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Same method for complex systems Dairy with 3 oil-cooled screw chillers

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CO2 cascade system with R134a

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Documentation of performance

and component by component evaluation

20 minutes to connect

(for a complex industrial plant it might be a few hours)

Size is not important

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Two stage centrifugal

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Presentation of data is key for analyses

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Start-up Part load Full load

Comp. eff

Start-up

Part load Full load

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COP +10% at full load

Compressor eff. 48% to 64% When part to

full load

Super heat. 0.8 K at part load -critical

8 compressors no need for part load > saving more than 5000 Euro

100%

67%

Temp. diff. 9.3 K

Secondary out – evaporation

Good ≈ 3-5 K

Temp. diff. 9.3 K

secondary out – condensing Good ≈ 1-4 K

Superheat affected by frost build-up

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on-line monitoring

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Fixed installation with web access

Energy monitoring - statistics

Early Warning

Hourly energy/cost statistics for owners

• Energy statistics - cost

• Monitor kWh and USD per hour

• Documents “energy profile” versus ambient temperatures

• Compare consumption with “energy profile”

• Document energy optimisation projects

• Benchmark different plant

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Energy Statistics

as optimisation

tool

Visualisation of optimisation June 14th

Green line is 12 month average kWh at daily ambient

Red line average daily temp

Auto-diagnostics to follow many plants

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Status of 27 roof top units on public office building

in Portland, Oregon - Oct 2011

Red = outside spec

Water chiller on naval ship in Texas

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Screw chiller with oil cooler

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Stable operation

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Performance of Screw chiller

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Low on charge

and large variation of flow

dependent on which pumps that were in operation

What was outside specification

• Charge - over and under charge

• Superheat setting - high and low

• Hunting valves - distribution

• Compressor efficiency - low

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Italian Supermarket in Milano saving corresponds to 16 000 Euro per year

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Drift som

tidigare

Adj.

controls

27% higher

COP

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Compressor Pack in Supermarket

Comp 2 Low Efficiency

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Comp 2 Low Efficiency

Average Comp. Efficiency

Compressor Pack in Supermarket Comp 2 Low Efficiency

Comp. Eff. 1, 3 and 4

Full load Full load Full load

Stab. Stab. Stab.

Optimisation project in 6 Carrefour hyper/supermarkets in Italy

Total saving 23% aprox. 318 000 Euro (416 000 USD)

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Data supplied

by contractor Scar

and

Carrefour Italy

for 7 month

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Optimisation measures

• Systematic work with optimisation is the prerequisite for savings

– Optimise evaporation

• Common with lower settings than required/design due to hysteresis in step control

• Frequently a problem in a display case is fixed by lowering set-point (never

readjusted even if problem fixed)

– Optimise condensing

• Define minimum allowed condensing for safe operation

• Detect fouling when it occurs – dust, leaves, seeds +++

– Optimise controls

• Short cycling should be reduced as much as possible – no urgency

• Cycling of fans > changes in sub cooling > flash gas > fluctuations in evaporation > cycling

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Optimisation measures cont.

• Correct under/over-charged systems

• Fix compressors with decreased efficiency

• Poorly insulated suction lines

• Poorly functional refrigeration economisers

• Poorly functional expansion valves

With instant feedback optimisation become dynamic

contractors and equipment owners can calculate cost - savings

Experience of 25 years of optimisation work

• Few system run as intended

• Multiple faults are more the rule than exemption

• Lack of information of design operation is a challenge

• Many times symptoms are addressed not the cause

• Lack of awareness of importance of proper service

• Social competence is more important than technical

• Learning curve is rapid when focus change

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Systems Efficiency Index New performance factor

• Overcome draw back of existing indicators

– COP/EER/SEER/Cooling load

• are totally dependent on rating conditions

• Sensitive for changes in flow

– Seasonal Performance factors

• Costly to get right

• Sensitive to Climate and use of building/plant

• Not suitable for benchmarking

• No info on what the problem is - costly to find faults

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System Efficiency Index

• Compares at actual operation condition how close

the process is to ideal.

• Defines Carnot efficiency based on “reference

temperatures”

• Can be used for benchmarking

• Allows to define where in system losses are

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SEI - Standards under development

• Germany – UK – Sweden

– Define segments that can be meaningfully

compared

– Define reference temperature for each segment

– Define system boundraries (auxiliary loads)

– Establish benchmarking levels

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Global Industry need

tools and training

to optimise

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Dynamics in real systems not

well taken care off or understood