Household Refrigeration Paper 4 Technical Support … 56 G.1 US MEPS Proposals 56 G.2 Approach to...

Household Refrigeration Paper 4 Technical Support Document on MEPS and Labelling for 2015 for Energy-using Refrigeration Equipment

August 2012

Paper prepared for E3 and DCCEE

Prepared by Energy Efficient Strategies

P A P E R 4 – T E C H N I C A L S U P P O R T D O C U M E N T F O R M E P S & L A B E L L I N G , H O U S E H O L D R E F R I G E R A T I O N

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INTRODUCTION

E3 has examined the recently published US 2014 MEPS levels, and has prepared a separate Regulatory Discussion Document (E3, 2012) that sets out a proposal for these MEPS levels to be adopted in Australia and New Zealand in 2015. Thi s technical support docum ent provides detailed information and background to som e aspects of the E3 Regulatory Discussion Document.

Previously, a series of papers were prepared that set out the techni cal details of the new MEPS levels to be implemented in the USA in 2014, present a road map for implementation of these MEPS levels in Australia in New Zeal and in 2015, and m ake a preliminary assessment of thei r possible impacts in the Austral ian and NZ m arkets. These papers are listed below and should be consulted for further information:

Paper 1: Summary of New MEPS Levels for Refrigerator in the

USA, October 2011.

Paper 2: Road Map for MEPS3 in Australia and NZ – Issues for

Stakeholders in the Alignment with US MEPS 2014, October

2011.

Paper 3: MEPS3 in Australia and NZ – Preliminary Impact

Assessment of New MEPS Levels in 2015, May 2012

Paper 4: Refrigerators and Freezers in Australia and NZ:

Technical Support Document on MEPS and Labelling for 2015

for Energy-using Refrigeration Equipment, May 2012 (this paper)

Regulatory Discussion Document: Government agency proposed

pathway to regulate refrigeration equipment sold to consumers in

Australia and New Zealand from about April 2015, E3, August

2012

Papers 1 and 2 were ci rculated to stakeholders prior to the recent E3 Whitegoods Forum held in Melbourne on 24 October 2011. A detai led presentation at the Forum set out the proposals to adopt the US 2014 MEPS levels for Australia and New Zeal and in 2015. Papers 1 and 2 and the presentati on from the forum are avai lable from: http://www.energyrating.gov.au/blog/resources/events-calendar/24102011.

Papers 3, 4 and the E3 Regulatory Discussion Document were released in August 2012 and ar e available from www.energyrating.gov.au under Program Publications.


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TABLE OF CONTENTS

INTRODUCTION i

OVERVIEW OF THIS PAPER 1

Key Issues for Discussion 2

Allowance for built in products 2Allowance for through the door ice dispensers 2MEPS levels for beverage coolers 2Target temperature for Group 2 and Group 3 products 2Compact products 2Energy Labelling Proposals 3

References 4

Annex A - New Energy Test Method 7

A.1 Overview 7A.2 Adoption of the IEC Test Method 7A.3 Key Elements of the New IEC Test Method 8A.3.1 Part 1 - General Requirements 9

Annex B – Test method conversion for MEPS 12

B.1 Internal and Ambient Temperatures 12B.2 Defrost Intervals for Variable Defrost Products 14B.3 Temperature During Defrost and Recovery 16B.4 Humidity Map for Ambient Controlled Anti-Condensation Heaters 17B.5 Field Adjustment Factors for Freezers 19B.6 Internal Icemakers 19B.7 Freezer Adjustment Factor 19B.8 Average vs Maximum Energy as MEPS Definition 20B.9 Summary of Test Method Conversion Factors used to Adjust MEPS 23

Annex C – Mapping US Product Categories to AS/NZS Groups 24

C.1 Introduction 24C.2 Automatic Icemakers (Internal) 24C.3 Automatic Icemakers (Through the Door Dispensers) 24C.4 Built-in Products 25C.5 Compact Products 26C.6 Door Allowance 26C.7 Adaptive Defrost Allowance 27

Annex D – Performance Considerations when Adapting US MEPS Levels 28

D.1 Introduction 28D.2 Capacity Performance Requirements 28D.3 Humidity Requirements 30


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Annex E – Technical Background for Energy Labelling 33

E.1 Introduction 33E.2 Current System for Energy Measurement 34E.3 Indoor Ambient Temperatures 35E.4 Response of Refrigerators and Freezers to Ambient Temperature 36E.5 User Interactions with Refrigerators and Freezers 42E.6 Rewarding Flexibility of Operation 44E.7 Adjusted Volume 45E.8 Energy Labelling Algorithm 48

Annex F – Compact Product Figures 50

F.1 Illustration of Compact MEPS by Group 50F.2 Discussion on Compact MEPS by Group 54

Annex G – Background information on wine storage and beverage coolers 56

G.1 US MEPS Proposals 56G.2 Approach to Cover These Products under AS/NZS 57

Annex H – Summary of Adjustments for MEPS 2005 61

H.1 Introduction 61H.2 Overall Test Method Differences and Considerations 62H.2 Group 1 63H.3 Groups 2, 3 and 4 63H.4 Groups 5T, 5B and 5S 63H.5 Groups 6C, 6U and 7 63H.6 Adjustments for AS/NZS MEPS Levels from 2005 to 2010 64

Annex I – Check list of issues to be covered by Part 2 65


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LIST OF TABLES Table 1: Temperature Specifications for US and IEC Test Methods ....................... 12

Table 2: US Humi dity Map t o be used t o assess MEPS under AS/NZS test method .............................................................................................................. 18

Table 3: AS/N ZS Humidity Map to be used to assess energy labelling under AS/NZS test method ......................................................................................... 18

Table 4: Calculati on of Hypothetical De clared Value UCL/1.1 for R efrigerators (mean=100) ...................................................................................................... 21

Table 5: Test Procedure Conversion Factors for US MEPS t o AS/NZS MEPS levels................................................................................................................. 23

Table 6: Weighting of Steady State Power with Expected Temperature Bins ......... 40

Table 7: Comparison of MEPS l evels for US MEPS 2001 and Aust ralia/NZ MEPS 2005....................................................................................................... 61


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LIST OF FIGURES

Figure 1: Measured Indoor Temperature Distribution for 40 Homes in Melbourne..35

Figure 2: Likely Annual Indoor Temperature Distribution in Australian Homes........ 36

Figure 3: Published COP data for R600a Compressor ............................................ 38

Figure 4: Typical Steady State Power Response to Ambient Temperature............. 38

Figure 5: Comparison of steady state power at different ambient temperatures – Group 1 ............................................................................................................. 39

Figure 6: Ambient temperature response curves for a range of products................ 41

Figure 7: Modelled Heat Gain into a Theoretical Refrigerator.................................. 47

Figure 8: Indicative Impact of MEPS 2015 Group 1 – AS/NZS test method ............ 50

Figure 9: Indicative Impact of MEPS 2015 Group 2 – AS/NZS test method ............ 51

Figure 10: Indicative Impact of MEPS 2015 Group 3 – AS/NZS test method .......... 51


Figure 12: Indicative Impact of MEPS 2015 Group 5T – AS/NZS test method........ 52

Figure 13: Indicative Impact of MEPS 2015 Group 6C – AS/NZS test method ....... 53

Figure 14: Indicative Impact of MEPS 2015 Group 6U – AS/NZS test method ....... 53


M E P S A N D L A B E L L I N G F O R 2 0 1 5 F O R E N E R G Y - U S I N G R E F R I G E R A T I O N E Q U I P M E N T

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OVERVIEW OF THIS PAPER This paper i s a techni cal support docum ent for the docum ent titled: Regulatory

Discussion Document: Government agency proposed pathway to regulate

refrigeration equipment sold to consumers in Australia and New Zealand from about

April 2015.

This paper provi des a range of techni cal information that underpi ns the Regulatory

Discussion Document. Stakeholders that have a deep i nterest in these m atters are advised to review the material in this paper closely.

This paper i s set out as a seri es of A nnexes that provi de in-depth information and discussion on a range of specif ic topics related to M EPS levels and energy labelling proposals for 2015 and beyond.

The topics covered are:

Annex A – provides an overview of the new IEC test method that will be adopted in Australia and NZ as part of the E3 Regulatory Discussion Document.

Annex B – examines in some detail the differences in the energy test m ethod in the USA and the new IEC test m ethod and sets out the rel evant conversions to m ake these as equivalent as possible when adapting and assessing MEPS levels from the USA.

Annex C – l ooks at the US M EPS categories and set s out approaches t hat maps these to current AS/NZS Gr oups and reduces the number of US categories through feature allowances. At thi s stage no speci fic allowance has been devel oped for compact products, but a range of issues are examined for this class of product.

Annex D – provi des an overvi ew of perform ance requirements in the IEC standard and how these m ay impact on the energy cons umption of products. At thi s stage no specific allowance has been devel oped to take i nto account perform ance requirements in the IEC standard.

Annex E – sets out the background and techni cal information that m akes up the energy labelling proposal in the E3 Regulatory Discussion Document.

Annex F – illustrates the US MEPS levels for compact products and presents a range of observations regarding the issues that this product category presents.

Annex G – provides som e details of the U S proposals to regulate w ine chillers and miscellaneous refrigeration products i n 2017 and sets out the techni cal steps proposed in Australia and NZ to regulate these products in 2015 and 2018.

Annex H – provides a l ist of the conversi on factors that were appl ied in 2005 when Australia adopted the US 2001 M EPS levels and provides some commentary on the similarity and differences in the process applied for 2015 MEPS levels.

Annex I – l ists a range of i ssues that may need to be consi dered when the current Part 1/ Part 2 standard structure is replaced by the IEC test method. A modified Part 2 will need to address a range of iss ues that are currently covered in Part 1 but that are not included in the IEC standard.



Key Issues for Discussion

There are a num ber of areas where specific comment from industry is sought on the proposals set out in the E3 Regulatory Discussion Document. These are briefly set out below.

Allowance for built in products

The option proposed is an allowance of 40 kWh/year for all groups except Group 5S, which will be given 100 kW h/year for products th at meet the definition. This is a new feature allowance.

Allowance for through the door ice dispensers

The option proposed i s an al lowance of 52 kWh/year for any groups whi ch have a through the door ice dispenser. This replaces the existing allowance of 128 kWh/year for this feature.

MEPS levels for beverage coolers

Proposals for regulation for MEPS of miscellaneous refrigeration products (including beverage coolers) are i ncluded in E3 Regulatory Discussion Document. As this specific technical proposal has not been canvassed previ ously, industry may wish to provide specific feedback on t his matter, including the MEPS levels and t he energy labelling proposal for cooled appliances.

Target temperature for Group 2 and Group 3 products

There is a si gnificant shift from AS/NZS4474.1 to the new IEC test m ethod (and a mismatch with the US test method) due to the change in (or definition of) frozen target temperatures for Group 2 and Group 3 pr oducts. Under AS/NZS4474.1 these were defined as -2°C and -9°C respectively. Under the US test method a single temperature of -9.4°C i s used for refri gerators (Category 1 and 1A). Under t he IEC test m ethod, such compartments could be classified as 0 star, 1 star and 2 star , which have target temperatures for operation as 0°C, -6°C and -12°C, respectively.

Compact products

The change of definition by t he US DOE duri ng the US 2014 M EPS determination now means that for most products there is now a discontinuity in the MEPS level at or around 219 litres (7.75 cu ft) of total volume (not adjusted volume).

In a general policy sense, thi s type of di scontinuity is undesirable as i t could encourage suppliers to reduce the apparent or claimed volume of thei r smaller products (in the range 220 l itres to 240 l itres) to be 219 l itres in order to get a significantly weaker MEPS level. An illu stration of the U S 2014 M EPS levels for



compact products (for typi cal configurations by Group) i s shown i n Annex F. Thi s Annex also has som e initial discussion and observati ons for each Group. The E3 Regulatory Discussion Document has no proposal s for an al lowance or separate requirements for compact products.

Energy Labelling Proposals

A range of far reaching cha nges to the appr oach to energy labelling are proposed in the E3 Regulatory Discussion Document. The intent of these changes i s to move the energy consumption values on the energy label, which are used by purchasers when selecting a new product, to be cl oser to the value that m ight be expected within the range of typical use. This w ill make the label value more consumer relevant and it w ill rank products more closely on their expected energy consumption during normal use, rather than at an abstract and unrelated test condition (with no use).



References

Adin 2012, Lucas Adi n, Project Manager, Appliance Standards Program , US Department of Energy, [email protected], personal communication, 18 Apri l 2012.

CSIRO 2010, Indoor Air Project Part 1: Main Report - Indoor Air in Typical Australian

Dwellings, The Centre for Austral ian Weather and Cl imate Research (CSIRO & Bureau of M eteorology), A report to the Ai r Quality Section, Environment Standards Branch, Department of t he Environment, Water, Heritage and the Arts. See http://www.environment.gov.au/atmosphere/airquality/publications/indoor-air-project.html

CSIRO 2012, Home Energy Project, see http://www.csiro.au/science/home-energy-evaluation for details.

Bansal 2002, Impact of different parameters on the energy consumption of household refrigerators, in ASHRAE Transactions 2002; Volume 108(1), Pradeep K Bansal , University of Auckland.

E3 2012, Regulatory Discussion Document: Government agency proposed pathway to

regulate refrigeration equipment sold to consumers in Australia and New Zealand from

about April 2015, prepared by E3, August 2012. See www.energyrating.gov.au under Resources/Program Publications.

EES 2000, Refrigerator MEPS 2004 Working Group - Final MEPS Levels, Prepared by Lloyd Harrington, EES on behal f of NAEEEC, Final paper 4 Decem ber 2000, see http://www.energyrating.gov.au/products-themes/refrigeration/documents-and-publications/?viewPublicationID=2476.

EES 2007, Impact of Changes in AS/NZS4474.1-2007 on Energy Consumption, by Energy Efficient Strategies, a di scussion paper for the Equi pment Energy Effi ciency Committee (E3), October 2007. Report 2007/13 avai lable from www.energyrating.gov.au in the electronic library.

EES 2008, Consultation Regulatory Impact Statement of proposed revisions to the

method of test and energy labelling algorithms for household refrigerators and

freezers, prepared by Energy Effi cient Strategies for E3, Report 2008/04, June 2008, see http://www.energyrating.gov.au/resources/program-publications/?viewPublicationID=345.

EES 2010, Household Refrigerators - Humidity Controlled Anti-Condensation Heaters, presentation to EL15/23, see http://www.energyrating.gov.au/resources/program-publications/?viewPublicationID=590.

EES 2011a, Paper 1: Summary of New MEPS Levels for Refrigerator in the USA, prepared by Ener gy Efficient Strategies for DCCEE, October 2011, see http://www.energyrating.gov.au/blog/resources/events-calendar/24102011.



EES 2011b, Paper 2: Road Map for MEPS3 in Australia and NZ – Issues for

Stakeholders in the Alignment with US MEPS 2014, prepared by Energy Effi cient Strategies for DCCEE, October 2011, see http://www.energyrating.gov.au/blog/resources/events-calendar/24102011.

EES 2012a, Paper 3: MEPS3 in Australia and NZ – Preliminary Impact Assessment of

New MEPS Levels in 2015, prepared by Energy Efficient Strategies for DCCEE, April 2012. See www.energyrating.gov.au under Resources/Program Publications.

IEC Draft Test Methods

The following draft standards were issued in January 2012:

• IEC 59M/33/CD: IEC 62552-1 Ed 1.0: Household refrigerating appliances –

Characteristics and test methods - Part 1: General Requirements;


Characteristics and test methods – Part 2 – Performance Requirements;


Characteristics and test methods - Part 3: Energy Consumption and Volume.

Australian and New Zealand Standards

• AS/NZS4474.1-2007 Performance of household electrical appliances —

Refrigerating appliances Part 1: Energy consumption and performance.

Amendment 2 to Part 1 was published in March 2011.

• AS/NZS4474.2-2009 Performance of household electrical appliances — Refrigerating Appliances Part 2: Energy labelling and minimum energy

performance standard requirements.

Amendment 1 to Part 2 was published in March 2011.

US DOE MEPS 2014 Documents

US regulatory documents can usual ly be obtained from the Government Printing Office Website www.gpo.gov. Code of Federal Regulations can be downl oaded from http://www.gpoaccess.gov/cfr. The latest regulations are available from the Electronic Code of Federal Regulations at http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&tpl=%2Findex.tpl.

US Department of Energy announced a f inal rule for revised MEPS levels for household refrigerators and freezers on 25 August 2011.

The relevant documents are:

• Final Rule - Energy Conservation Standards for Residential Refrigerators,

Refrigerator-Freezers, and Freezers (332 pages);

• Technical Support Document (1031 pages);

• Notice of Data Availability (NODA) for refrigerators and freezers (5 pages);

• Using the Experience Curve Approach for Appliance Price Forecasting (16 pages).



These documents are available from: http://www1.eere.energy.gov/buildings/appliance_standards/residential/refrigerators_freezers.html.

In addition, the US finalised a new test procedure for refrigerators and freezers:

• Federal Register,/ Vol. 75, No. 241, Thursday, December 16, 2010, Rules and

Regulations. Page 78810, 10 CFR Part 430 Energy Conservation Program for Consumer Products: Test Procedures for Refrigerators, Refrigerator-Freezers,

and Freezers; Final Rule and Interim Final Rule (66 pages).

• Federal Register, Vol. 77, No. 16, Wednesday, January 25, 2012, page 3559,

Energy Conservation Program for Consumer Products: Test Procedures for

Refrigerators, Refrigerator-Freezers, and Freezers – Final Rule (21 pages)

The amended Code of Federal Regulations (CFR430) with the new MEPS levels was formally published in the Federal Register on 15 Septem ber 2011 (Federal Register / Vol. 76, No. 179 / Thursday, Septem ber 15, 2011 / Rul es and Regul ations, page 57516) – see http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR.

These new M EPS levels come into force in the US on 15 Sept ember 2014. The following source documents on the above website should be consulted for details.

Title 10: Energy - US Code of Federal Regulations PART 429—CERTIFICATION,

COMPLIANCE, AND ENFORCEMENT FOR CONSUMER PRODUCTS AND

COMMERCIAL AND INDUSTRIAL EQUIPMENT. Available from US Governm ent Printing Office Electronic Code of Federal Regulations at http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&tpl=%2Findex.tpl.

Title 10: Energy - US Code of Federal Regulations PART 430—ENERGY

CONSERVATION PROGRAM FOR CONSUMER PRODUCTS. Available from US Government Printing Office http://www.gpoaccess.gov/cfr - search for 10CFR430.

US DOE MEPS 2017 Documents – wine storage and miscellaneous refrigeration

US regulatory documents for wine chillers and miscellaneous refrigeration products are available at: http://www1.eere.energy.gov/buildings/appliance_standards/residential/refrigerators_freezers.html.

Of particular importance at this site are the following documents:

Energy Conservation Standards: Rulemaking Framework Document for Wine Chillers

and Miscellaneous Refrigeration Products, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Building Technologies Program, 6 February, 2012. See http://www1.eere.energy.gov/buildings/appliance_standards/pdfs/wc_misc_refr_framework_02_06_12.pdf.

Framework Public Meeting for Wine Chillers and Miscellaneous Refrigeration

Products, presentation by Lucas Adi n, US DOE, 22 February 2012. See http://www1.eere.energy.gov/buildings/appliance_standards/pdfs/wc_fw_meeting_presentation_draft.pdf.



Annex A - New Energy Test Method

A.1 Overview

IEC SC59M has been developing a new global test method for household refrigerators for some years. This is a full revision of IEC62552 Performance of electrical household

and similar cooling and freezing appliances - Characteristics and test methods and will replace the current Edi tion 1 on publ ication. This new draft standard was rel eased as a second committee draft in January 2012. The new test method is split into 3 parts as follows:

• Part 1: General Requirements (59M/33/CD)

• Part 2: Performance Requirements (59M/34/CD)

• Part 3: Energy Consumption and Volume (59M/35/CD)

Comments on these drafts cl osed on 20 Ap ril 2012. Stakeholders can obtain a copy from Standards Australia or the Department of Climate Change and Energy Efficiency on request.

Part 1 is definitions and general and documents requirements for instrumentation, test room, configuration and other aspects that apply to all tests in other parts.

Part 2 is performance tests – these are to ensur e that the refri gerator works properly and is fit for purpose. Thi s includes storage test (equi valent to the tem perature operation test i n AS/NZS4474.1) and a range of other performance based tests including performance requirements for wine storage cabinets.

Part 3 is nominally energy consum ption (all aspects) and determ ination of volume, which is of critical interest for energy regulators and suppliers.

A Committee Draft for Voti ng is expected in the thi rd quarter of 2012. The new IEC standard is likely to be published in 2013.

A.2 Adoption of the IEC Test Method

As part of the process of adopting new M EPS levels for 2015 and t he associated regulatory changes, A ustralia and N Z will be adopting this new IEC test m ethod for energy consumption and performance. This is likely to be under the new Greenhouse and Energy Minimum Standards (GEMS) legislation in Australia.

The published IEC test method will be used as the basis for testing in A ustralia and NZ once the new regul atory requirements for 2015 are settl ed. Any variations to the IEC test method will be included in a governm ent determination, which may vary the details of the test method, where applicable.

As the IEC test method is still under developm ent, there are a num ber of issues that are still being finalised. In particular, these include:



• Revising the acceptable power spread for the 3 block stability method in Part 3 Annex B;

• Inclusion of warni ngs regarding defrost and recovery energy when the evaporator is dry (frost free products);

• Consideration of the fact ors that are used to determ ine the defrost i nterval for variable defrost products and the associ ated algorithm – currently the current formulation gives a rel atively short defrost i nterval, which may provide insufficient reward for smart controls during normal use.

• Rear clearance requirements for ener gy and perform ance tests (test room setup);

• Part 2 storage tests – t he overall test has been revised and some fine tuning is still being incorporated; refined temperature limits are also under consideration;

• Development of a test report format.

There are several other issues that may be included in the IEC test method (subject to provision of com ments and acceptance of these com ments through the norm al committee process). These include:

• Inclusion of a pul l down test (com parable to the test currentl y defined in AS/NZS4474.1) to ensure sufficient refrigeration capacity;

• Adjustments to the warm est test pa ckage temperature for the Part 2 Storage Test to align more with the requirements for energy testing;

• Inclusion of perform ance requirements with respect to sweati ng and runni ng moisture under normal use conditions.

These additional points may be accepted by IE C in 2012. However, i f not, they are likely to be included in a determination as a variation for Australia and New Zealand.

The only other com ponent of the IEC standard that requires specification via a determination is the i nclusion of regi onal requirements for ambient controlled anti-condensation heaters. Thi s is because IE C do not speci fy any val ues humidity requirements as these are necessari ly specific to each regi on. The val ues currently used in AS/NZS4474.1-2007 Amendment 2 (2011) Appendix S will be used for energy labelling as part of the determination. See also B.4 of this paper for more details.

A.3 Key Elements of the New IEC Test Method

The purpose of the new test standard is to provi de a gl obally aligned approach to testing of househol d refrigerating appliances to determ ine performance and energy consumption.

The new IEC test m ethod is a so cal led “LEGO Block” approach to energy testi ng, where each of the cri tical components of energy consum ption are separatel y quantified and reported. T he components that are r equired and how they are assembled in order to be relevant for A ustralia and New Zealand will be set out in the Part 2 regulatory standard. They key el ements for energy testing are outl ined briefly below.



The most significant differences between the exi sting AS/NZS m ethod and the new IEC test method are in the post-test data handling and calculation requirements. The IEC standard i s somewhat more complex because it has more data processing and more validity checks. However, the i ncreased complexity in calculation is offset by much greater flexibility in testing and scheduling. The IE C standard does allow considerably more flexibility w ith respect to the sequence of e vents and measurements, as the components of energy cons umption are quanti fied and reported separately (e.g. st eady state power consum ption, incremental defrost and recovery energy and tem perature deviation, defrosting frequency are all reported as separate values under IEC, whi ch are then combined into the required energy value later).

The new IEC method has additional tests and conditions that are to be measured over and above AS/NZS, most notably a repeat of the energy consumption at an additional lower ambient temperature condition (16°C) and a l oad processing efficiency test (a proxy for the energy requi red to extract heat loads during normal use). The energy test at lower ambient will be included into this regulatory change and the inclusion of processing efficiency is also proposed.

A.3.1 Part 1 - General Requirements

Part 1 definitions are broadly consistent with current definitions.

The most significant requirements in test room setup and i nstrumentation in Annex A are:

• Uncertainty requirements for e nergy and tem perature measurements (expanded uncertainty not more than 0.5K)

• Different thermal mass of ai r temperature sensors (ISO s ensors, brass or copper 25g = 5g water equi valent) (AS/NZS allow 2.3g to 20g of water equivalent, which includes IEC sensors within the range, but many labs still use old specification at the heavier end which will no longer be permitted)

• Changes in temperature stability requirements for test room

• Changes to test room configuration (side partition clearances, position of ambient temperature sensors, requirement for platform)

• Default rear clearance requirements (this is an area still under discussion, but is likely to be less than the current 50mm in AS/NZS4474.1)

• Ambient test temperatures for energy consumption are 16°C and 32°C

Part 1 Annex C test packages are now onl y a single size for all relevant tests (500g) (Part 2 Storage Test) – this dramatically simplifies loading plans.

Part 1 Annex D Determ ination of Com partment Average Ai r Temperatures - these requirements are generally similar to AS/NZS requirements, with some differences:

• 2 additional sensors are added for tal l freezer compartments >1.2m in effective height.



• The location of the fresh food (unfrozen) sensors are slightly altered (one basic setup is now specified for all unfrozen configurations – this is a simplified layout that is not dependent on whether the product has crispers or not).

• Effective height and width rules from AS/NZS have been generally adopted

• Small and low height rules from AS/NZS have been generally adopted

• Clearance for tem perature sensors from all internal surfaces i s now general ly 25mm.

A.3.2 Part 2 – Performance Requirements

Part 2 contai ns a range of perform ance requirements for refri gerators. The Storage Test is broadly comparable with the Te mperature Operation Test of AS/NZS4474.1 (although many of the technical details hav e been adjusted), and this new test w ill continue to be a performance pre-requisite for energy labelling and MEPS in Australia and NZ.

The wine storage cabinet performance test in Part 2 is also likely to be a requi rement for these types of products.

If the pull down test is included as a separate test in Part 2, then this w ill be required for Australia and N Z. Otherwise it w ill be included as part of the test m ethod determination.

Generally the other performance tests in Part 2 are will not be required.

A.3.3 Part 3 – Energy and Volume

Part 3 sets out a range of energy tests and also the determination of volume.

Clause 3 (Determination of energy and determ ination of volume) maps out the tests and test components defined in this Part. It references the general measurements that are to be undertaken:

• Annex A: Set up for energy testing – requirements for energy in addition to Part 1 – sets parti cular requirements for m anually switched anti-condensation heaters and autom atic icemakers (which are com patible with AS/NZS4474.1-2007 Amendment 2, except that ice storage buckets must remain in place)

• Annex B: Steady state energy (power) and tem perature is determined during the stable part of operation (between defrosts where applicable) (same as “Part 1” of AS/NZS4474.1-2007 Appendix Q)

• Annex C: Defrost & recovery – this is the normal component of a typical defrost control cycle (same as “Part 2” of AS/NZS4474.1-2007 Appendix Q) (unsteady part around a defrost and recovery). Th is includes defrost and recovery incremental energy (in effect this is the extra energy associ ated with a defrost over and above the steady state condi tion) and defrost & recovery tem perature change (quantifies the temperature deviation during a defrost and recovery event, has units in K·hours – can be positive (if warmer) or negative (if colder)).



• Annex D: Defrost frequency – this is a measured value for compressor run time controllers (or fixed time controllers). It is a calculated value for variable defrost units (variable defrost now replaces the term adaptive defrost).

• Annex E: Num ber of test poi nts and interpolation – this is equivalent to AS/NZS4474.1-2007 Appendix J, L & M , but some new m athematical approaches are included (e.g. matrices).

• Annex F: Specified auxiliaries – the only relevant auxiliary is ambient controlled anti-condensation heaters and this w ill be specified in the determ ination to be the same as the current hum idity requirements in AS/NZS4474.1-2007 Amendment 2 (2011) Appendix S for energy labelling (US humidity map will be specified for MEPS).

• Annex G: Processing efficiency – this is a new test that i s conducted as part of the standard energy tests. T he configuration of the re frigerator remains the same as a standard energy consum ption test. A defined water load is added to the refrigerator and the test is cont inued until it reaches equilibrium . It is effectively a 24 hour extension of the typical energy test period (this is normally conducted with all compartments at or below the target temperature).

• Annex H: Volume determination – this is significantly different to either gross or net volume in AS/NZS4474.1-2007. The approach i s based on a W YSIWIG approach and should be relatively sim ple for labs to undertake. S uppliers will continue to use technical drawings as the basis for declaring volumes.

With regard to energy testi ng, Annex B and Annex C are t he most important components. Quite strict r equirements for stability of power and tem perature are required in order to get val id results. It is usually advisable to have at l east 6 hours of steady operation before each def rost. However, defrost a ttributes can be determ ined at different settings to the settings used for steady state measurements, so this makes the overall approach to testing a lot more flexible.



Annex B – Test method conversion for MEPS The US has made strident efforts to move towards the new IEC test m ethod in recent years. As a precursor t o their new M EPS levels in 2014, they released a new t est method for energy m easurement. This was mostly finalised in December 2010 (DOE 2010) and som e minor adjustments to the method were rel eased in January 2012. The US test m ethod was settl ed some time before the IEC st andard was fi nalised. There are som e small differences – some of these have occurred because the US were unable to anti cipate all technical details in the IEC, but m ostly these have occurred because the US deci ded to take a different approach to the IEC on som e technical issues.

The relevant US documents are:

Test Procedures for Refrigerators, Refrigerator-Freezers, and Freezers: Federal

Register, Vol. 75, No. 241, December 16, 2010, page 78810 (Final rule, Interim final

rule).

Test Procedures for Refrigerators, Refrigerator-Freezers, and Freezers: Federal

Register Vol. 77, No. 16, January 25, 2012, page 3559 (Final rule).

Importantly, the US has m oved to standardise internal target temperatures for energy consumption to be cl ose to the IEC val ues. The US conti nue to use onl y the warmer ambient temperature (32.2°C) for assessment of MEPS (and f or their local energy labelling program).

There are a number of technical differences between the final US test method and the IEC test method. Some of the more significant ones are set out below in this Annex.

B.1 Internal and Ambient Temperatures

While the US has broadl y aligned with the forthcoming IEC test m ethod for refrigerators, they have speci fied internal temperatures and ambient temperatures as integer values of degrees Fahrenheit rather than degrees Celsius, which is used in all IEC and ISO standards. This results in a small difference in the temperatures specified for each test method.

The following table sets out the main temperature differences.

Table 1: Temperature Specifications for US and IEC Test Methods

Parameter US Specification °F US Specification °C IEC °C

Fresh Food 39 3.9 4.0

Freezer (3* or 4*) 0 -17.8 -18.0

Short term frozen (2*) 15 -9.4 -12.0

Ambient air 90 32.2 32.0 Note: Temperature for frozen compartment (2*) in a “refrigerator” appears not to be changed in the US test method when they aligned with IEC. 1 star (1*) are not covered directly in the US (compartment temperature of -6°C under IEC). This is an area where some stakeholder feedback is sought.



It is technically possible to require all tests under the IEC to evaluate the energy at the US target temperatures. But this has many complications because many products do not use i nterpolation to determ ine energy c onsumption. For i nternal temperatures there appears to be no practi cal option other than to m ake an estimate of the energy impact of the temperature difference under each test method and apply this to the test method. Additional extensive analysis conducted i n Paper 3 gi ves us a sound technical basis for esti mating the energy i mpact of sm all changes i n internal compartment temperatures. The approach for undertaking this is set out in the section on adjustments to MEPS levels (B.9).

The new IEC test and the US test m ethod use an average of al l freezer temperature sensors in order to get an accurate esti mate of the com partment temperature. So there is no adj ustment necessary f or this factor when adapt ing US M EPS levels. However, it should be noted that AS/NZS4474.1 speci fies the warm est 4 freezer sensors (of 5 sensors in the freezer) to determine the temperature, so there is a small change in the historical approach to energy measurement (but this is irrelevant as this approach will no longer be used).

It is also worth noting that the IEC m ethod provides a technical basis for estimating the energy consum ption for any sel ected internal compartment temperature through interpolation. So for a suppl ier operating in the US and i nternational market, the IEC method could provide a precise value for energy at the condi tions specified for each test method (if desired) (which is in fact what US suppl iers may elect to do). But as noted above thi s approach i s not considered desirable or practi cal for Austral ia and NZ alone. However, the US take a very rest rictive view on interpolation issues – they do not permit triangulation (for example).

Ambient temperature is more difficult. Analysis of real refrigerators suggests that the slope of energy in response to changes in ambient temperature at 32°C is of the order of 5% to 10% per degree K. Thi s means that the nom inal difference in ambient temperature (0.2K) could account for a 1% to 2% energy impact.

Fortunately, the IEC committee anticipated the potential problem of harmonisation with the US and i ncluded an am bient correction formula to correct the m easured energy consumption (at an actual measured ambient) back to a norm alised energy consumption at the nominal ambient temperature. This would then permit tests to both test methods within the al lowable tolerance range (noti ng that generally the IEC standard does not perm it deliberate adjustment of target param eters within the permitted tolerance range, but this may be an explicit exception).

While this correction formula is rather empirical (based on very approxi mate physical characteristics) it does tend to push the measured energy in the correct direction when the actual ambient temperature during the test i s not prec isely at the target am bient temperature. This is an i mportant addition because under al l existing test m ethods there is no such am bient correction. This means that two l abs could be operati ng within the allowable tolerance of ambient temperature of 32°C ±0.5K and these could, in some cases, have an energy that coul d be as much as 5% to 10% different due to the permitted ambient temperature variations alone. Given the i mportance of thi s ambient temperature correction, considerable effort i s being invested to ensure that this is robust and as accurate as possible. This is one of the areas w here IEC is still



undertaking investigations, so the values included in the correction for M EPS are still subject to revi sion. This is an i mportant area where the IEC outcom e should be adopted as part of the new test m ethod in Australia and New Zeal and, where this is confirmed through data analysis.

B.2 Defrost Intervals for Variable Defrost Products

Under the IEC test m ethod, products that use any sort of electronic control to set the defrost interval are cl assified as vari able defrost controllers. Effectively these are defrost controllers that are neither compressor run ti me controllers nor fi xed time controllers. The requirements for variable controllers are generally compatible with the current requirements for adaptive defrost products under AS/NZS4474.1.

In the IEC m ethod, the suppl ier has to declare the l ongest and shortest possi ble defrost interval that i s likely under an operating ambient temperature of 32°C and 16°C. This declaration then sets the defrost interval that i s used to cal culate the energy consumption at each speci fied temperature. If no val ue is declared, ungenerous default values are nominated.

As part of the IEC test m ethod, the product may be tested to ensure that the shortest possible and l ongest possible values can act ually be achi eved. The m ost important parameter (that has the largest effect on the calculated defrost interval) is the shortest possible defrost interval. This is fairly easy to verify in that a test can be undertaken i n a high humidity test room with a large number of door openi ngs to see whether the actual shortest defrost interval is equal to or longer than the declared minimum value.

The calculation of defrost interval in the IEC is an area that is still being considered – some small adjustments to the calculations may still be m ade. One issue is a c ase where the defrost i nterval observed duri ng the test i s inconsistent with the declared values.

Under the US test m ethod these types of defrost control lers are cal led long-time automatic defrost systems. The US use an equati on that is similar to IEC (i n fact the IEC approach was deri ved from the US approach) , but the resul ting defrost intervals are quite a bi t longer that would be cal culated under the IEC m ethod. Also, the US method allows suppliers to use fairly generous default values, which effectively give a default defrost i nterval of 48 hours (24 h ours of com pressor run ti me). The l ongest conceivable defrost i nterval in the US is 80.5 hours (al l at 32. 2°C ambient). This compares to an IEC defaul t defrost i nterval of 10 hours (where no val ues are declared) and the l ongest conceivable defrost interval of 30 hours (at an am bient temperature of 32°C).

While the IEC values are considered to be more realistic in terms of normal use (and are still subject to review and discussion), this does present a proble m in that the differing defrost intervals w ill have a significant im pact on energy consum ption. For example, if the typi cal incremental defrost and recovery energy for a refri gerator-freezer is about 100 W h per defrost, then a defrost that occurs once per 24 hours equates to 36.5 kW h per year. If the defrost interval is 12 hours thi s is 73 kW h per year and at an interval of 48 hours i t is 18.25 kWh per year. Given that MEPS levels are often around 350 kWh per year or less (for a large refrigerator-freezer), the defrost



energy ranges from 10% to 20% to 5% for these 3 exam ples. The i nclusion of the adaptive defrost allowing in MEPS 2005 in Australia was an imperfect (and somewhat crude) approach to dealing with this issue.

Fortunately, the IEC test method now separatel y quantifies the i ncremental energy and temperature impact of defrost and recovery events. This allows the calculation of energy consumption at any defrost i nterval – this is a paper cal culation that does not require any further testing. This provides the means for a precise solution to the issue of different defrost intervals in the US and under IEC when assessing compliance with MEPS.

The final US test procedure on 25 January 2012 set new defaul t values for CT L and CTM 6 hours and 96 hours respec tively (US DOE, Federal Register, Vol. 77, No. 16, Wednesday, January 25, 2012). (For referenc e the current default values for CTL and CTM are 12 hours and 84 hours respectively and these remain in place until 2014).

Under the US test procedure, the defrost calculation is given below.

Where:

CT is the defrost interval in compressor run time

CTL is the least or shortest compressor run time between defrosts in hours rounded to the nearest tenth of an hour (g reater than or equal to 6 bu t less than or equal to 12 hours)

CTM is maximum compressor run ti me between defrosts i n hours rounded to the nearest tenth of an hour (greater than CTL but not more than 96 hours);

F is equal to 0.2

The US default values are now:

CTL = 6 hours

CTM = 96 hours

CT = 24 hours of com pressor run time between defrosts (nominally 48 hours elapsed time for single speed compressor with run time

1 of 50%)

The US Department of Energy (Adin, 2012) has advised that most US suppliers have been supplying actual values for CTL and CT M since early 2011 and that the m ost common values submitted are 8 hours and 96 hours respecti vely. This gives an average defrost interval for the calculation of MEPS as 30 hours of compressor run time (nominally 60 hours of elapsed time).

A defrost interval of tdf equal to 60 hours w ill be used to determined energy under the IEC test method for assessment of MEPS compliance.

1 The US test method remains silent about inverter type systems. An inverter that runs continuously

would have a very short defrost interval, which would disadvantage this technology.



B.3 Temperature During Defrost and Recovery

While the US has al igned the IEC wi th regard to the broad defi nition of defros t and recovery period (and i mportantly this now includes any pre -cool before the defrost heater operates wi thin this period), there i s a di fference in the m easurement of compartment temperatures under each test method.

Under the ol d test m ethod AS/NZS4474.1-1997 and under t he previous US test method, the com partment temperature is determined during the steady state part of the test period. This was a problem as it encouraged slow recovery after a defrost as a means of reduci ng energy consum ption (resulting in long periods of warm temperatures, which has major food quality issues).

To address thi s attempted circumvention, the revi sion of AS/NZS4474.1 i n 2007 changed the tem perature determination period to be sam e as the energy determination period (i.e. over the whole defrost control cycle). This in effect penalised compartments that stayed warm by rai sing the m easured temperature for energy consumption determination. This approach has been adopted i n the IEC and i s the most technically sensible approach as i t locks energy and tem perature measurement periods together, thus thwarti ng any atte mpt at ci rcumvention through tem perature adjustments (as there i s no time where the temperature is not measured and used in the calculation).

Unfortunately, the U S still does not determ ine the tem perature (or tem perature deviation) during a defrost and recovery period. This w ill mean under the U S test method, most compartments will appear to be slightly colder than they w ould under the IEC test m ethod (which does i nclude temperature measurement for the defrost and recovery). Thi s issue is only relevant to frost free products. Unfortunatel y, the impact varies by refrigerator – poor refri gerators may have a si gnificant temperature rise during defrost and recovery while some good refrigerators may even have a lower average temperature during the defrost and recovery (usual ly attained by a strong pre-cool prior to defrost). The US have a ttempted to l imit circumvention by putti ng limits on the durati on of the defrost and re covery period (which is necessarily complicated). This is a area where an attem pt to develop a single adjustment factor would have been very non-uniform impact at a model level.

Fortunately, the IEC test method separately quantifies the temperature impact during defrost and recovery. In order to get an equi valent value under the US test m ethod, the temperature deviation during defrost and recovery can be expl icitly eliminated from the energy calculation. This will mean some small adjustments to the calculations that are used to derive the energy consumption for MEPS (including interpolation), but this is a very pure and concise conversion process and w ill give an accurate conversion between the test m ethods. The only slight disadvantage is that products that warm significantly during the defrost and recovery period w ill not be penalised for MEPS assessment (but they will be for energy labelling).



B.4 Humidity Map for Ambient Controlled Anti-Condensation Heaters

When a refri gerator operates i n a hum id environment, the temperature gradients around door seals, which are less well insulated than other parts of the cabinet, can mean that humidity can condensate in these areas. Most products use part of the hot gas from the compressor to the condenser to heat the area around the door seal s to prevent sweating (or condensation).

For some product configurations, electric anti-condensation heaters are required to do this task because i t is not possible to pipe hot gas to certai n parts of the cabi net. The most common configuration is the central door seal on a Group 5B model with French doors.

Ambient controlled anti-condensation heaters are a rel atively recent devel opment, appearing on the m arket in about 2005. Thes e types of control s are general ly considered to be a good thi ng as they reduce the energy r equired, depending on the ambient conditions around the refri gerator (compared to a heater that i s continually on).

The US devel oped a procedure to deal with these types of products as part of a waiver process proposed by General Electric in the USA. Thi s approach has now been formalised in the new US test method.

The IEC has used the sam e basic approach as the US approach but the IEC has included 3 ambient temperatures to specify humidity distributions (the US has just one temperature). The IEC tem peratures are the sam e as those speci fied as AS/NZS4474.1-2007 Amendment 2. It is important to note that IEC do not specify any humidity map in the standard, as this w ill necessarily vary by country and region as it is climate dependent.

The US humidity levels specified in the U S test procedure are quite low and this w ill result in fairly low energy consum ption of am bient controlled anti-condensation heaters. The humidity map current defined for Austral ia has been based on weather data for 5 capital cities. The details are set out in EES (2010). If the Australian levels were used for assessment of MEPS, these products would have a hi gher calculated energy.

As for other com ponents of the IEC st andard, the addi tional energy from these devices is included as part of a paper cal culation, based on the heater operation map supplied by the manufacturer and the humidity map specified in the test method.

In order to get a fully aligned energy values with the US, the US humidity map will be used to assess energy consum ption for the purposes of M EPS 2015 as set out in Table 2.



Table 2: US Humidity Map to be used to assess MEPS under AS/NZS test method

Relative humidity band

RH band mid-point

Probability at 16°C

Probability at 22.2°C


0-10% 5% 0.00% 3.40% 0.00%

10-20% 15% 0.00% 21.10% 0.00%

20-30% 25% 0.00% 20.40% 0.00%

30-40% 35% 0.00% 16.60% 0.00%

40-50% 45% 0.00% 12.60% 0.00%

50-60% 55% 0.00% 11.90% 0.00%

60-70% 65% 0.00% 6.90% 0.00%

70-80% 75% 0.00% 4.70% 0.00%

80-90% 85% 0.00% 0.80% 0.00%

90-100% 95% 0.00% 1.50% 0.00%

Source: CFR 430 Appendix A, clause 6.2.3: Variable Anti-Sweat Heater

Note: US values add to 99.9%.

Note that the current A S/NZS humidity map will continue to be used for energy labelling.

Table 3: AS/NZS Humidity Map to be used to assess energy labelling under AS/NZS test method

Relative humidity band

RH band mid-point




0-10% 5% 0.00% 0.00% 0.03%

10-20% 15% 0.06% 0.06% 0.33%

20-30% 25% 0.60% 1.62% 2.35%

30-40% 35% 2.76% 9.24% 2.56%

40-50% 45% 6.93% 12.72% 3.57%

50-60% 55% 8.01% 11.70% 1.11%

60-70% 65% 5.55% 11.40% 0.05%

70-80% 75% 3.30% 7.92% 0.00%

80-90% 85% 1.80% 3.48% 0.00%

90-100% 95% 0.99% 1.86% 0.00%

Notes: Values are as per A/NZS4474.1-2007 Amendment 2 (2011). The values above have been weighted by the specified time at each ambient temperature (30% @ 16°C, 60% @ 22°C, 10% at 32°C) as specified, so the numbers appear different to the published standard so that they are presented in the IEC format, but the net effect is identical. Note that there is a typographical error in weightings included in Appendix S of Amendment 2. The weightings included in the example in Appendix R are correct and have been used here.

The system-loss factor of 1.3 assumed in the US is the same as IEC and AS/NZS.



B.5 Field Adjustment Factors for Freezers

As part of the US test m ethod, the measured energy consumption of separate vertical freezers is multiplied by 0.85 and the m easured energy consum ption of separat e chest freezers is multiplied by 0.7. The DOE regulation states:

The factor k adjusts the measured energy use for freezers for consistency with

consumer usage patterns of these products. Its value is 0.85 for upright freezers and

0.7 for chest freezers. Applying these values means that the calculated energy use of

upright freezers is 15% lower than the measured energy use. Correspondingly, the

calculated energy use of chest freezers is 30% lower than the measured energy use.

These factors have been built into the energy labelling and MEPS levels for the US as they are a core part of t he test m ethod itself. These need to be taken i nto account when comparing or converting US values.

B.6 Internal Icemakers

The US test m ethod adds a fl at energy consumption value of 84 kW h/year where a product has an automatic icemaker. The same value is applied to all products with this feature. The DOE not e that thi s as a pl aceholder value until the test m ethod to measure the incremental energy associated with ice making has been finalised.

The IEC standard onl y has a draft m ethod for measuring the energy consum ption associated with making ice for tank type icemakers (these are common in Japan). The IEC method for continuous ice makers (mains water supply) has not been developed, pending the devel opment of a sui table US method (where these products are m ost common).

The added energy val ue in the US test pr ocedure needs to be taken i nto account when comparing or converting US values. Even if there was a test m ethod to make ice, it is not clear whether deployment of the method would be warranted in Australia and NZ (for energy labelling) as the volum e of ice consum ed is likely to be considerably less.

B.7 Freezer Adjustment Factor

The freezer adjustment factor (FAF) i s used to scale compartment volumes to reflect their relative temperature of operati on relative to that of a fresh food com partment. The equations for this is well established as follows:

FAF =

For the US this is given by (in degrees F):

FAF = = 1.7647



The US regulations specify a FAF of 1.76 for MEPS in 2014. Note that previously the US FAF was 1.63 for refrigerator-freezers and 1.73 for separate freezers (these reflect the previous temperatures of operation).

Under the IEC test m ethod, the FAF i s based on the target tem peratures for each compartment type. For freezers this is given by (in degrees C):

FAF = = 1.7857

It is proposed that a FAF of 1.79 be used fo r freezers when cal culating the adjusted volume for MEPS and energy labelling under the new IEC test method.

B.8 Average vs Maximum Energy as MEPS Definition

Under the US regulations, manufacturers have a defined process for how they declare the energy consumption of a product for energy labelling and MEPS. These are set out in a new regulatory section in the Code of Federal Regulations as follows:

Title 10: Energy

PART 429—CERTIFICATION, COMPLIANCE, AND ENFORCEMENT FOR CONSUMER PRODUCTS AND COMMERCIAL AND INDUSTRIAL EQUIPMENT

As this is a fai rly new regul ation that has not yet been i ncorporated into printed regulations, so i t is best to obtai n a c opy from the El ectronic Code of Federal Regulations http://ecfr.gpoaccess.gov

The regulation has a general requirement that products selected for the purposes of testing and declaration shall be selected at random. This has to be done i nitially and as part of an annual certification report which is now required for all refrigerators and freezers. Most suppliers undertake this testing in house (Adin, 2012).

There is a general minimum sample of 2 uni ts for testing of most products regulated for energy in the US. Manufacturers have to declare an energy value that is the higher of:

A) The mean energy of sample; or

B) the Upper Confi dence Level (UCL) of the sam ple divided by 1.1, where UCL i s given by:

UCL =

Where:

x is the sample mean

t0.95 is the Student t stati stic for a 95% one tailed confidence interval with n-1 degrees of freedom

s is the sample standard deviation

n is the number of samples tested



The following table shows the val ues of UCL/1.1 for a hypotheti cal product wi th a mean of 100 and a standard devi ation shown in the first column. Any combination of sample size and standard devi ation that gi ves a val ue of UCL/1.1 of l ess than 100 means that the suppl ier is able to decl are the m ean of the sam ple as the decl ared value for MEPS certification. The value only really exceeds 100 where the sample size is small (2 or 3) and the standard deviation is larger (>6%).

Under the hi storical AS/NZS system, a sam ple of 3 products i s mandated for registration purposes and no change to thi s approach i s proposed as part of thi s regulatory upgrade. The information in CFR429 confirms that the US requirements for MEPS is based on the product mean energy and is not a maximum permitted energy consumption as currently defined in Australia.

It is important to note that the US r equirements are for certi fication testing and products have to be sampled and tested each year and an annual report filed.

Table 4: Calculation of Hypothetical Declared Value UCL/1.1 for Refrigerators (mean=100)

Degrees Freedom 1 2 3 4

Sample Size 2 3 4 5

t0.95 one sided

Standard Dev

6.314 2.92 2.353 2.132

0 90.9 90.9 90.9 90.9

1 95.0 92.4 92.0 91.8

2 99.0 94.0 93.0 92.6

3 103.1 95.5 94.1 93.5

4 107.1 97.0 95.2 94.4

5 111.2 98.6 96.3 95.2

6 115.3 100.1 97.3 96.1

7 119.3 101.6 98.4 97.0

8 123.4 103.2 99.5 97.8

9 127.4 104.7 100.5 98.7

10 131.5 106.2 101.6 99.6

Source: US DOE CFR429

The US method for permitted declarations does penalise products that have a wi der standard deviation of measured values (higher production variability). There is merit in adopting such an approach for energy labelling as this offers greater consu mer protection for products with a higher level of variability. It is not considered necessary to adopt such an approach for MEPS because the current and future requirements as set out for A S/NZS above still requires te sting of 3 units and does not perm it any single test result to lie above the MEPS limit for the product (for registration or check testing, as MEPS is converted to a maximum permitted energy). This effectively allows suppliers that have low production variability to have a m ean that is closer to the MEPS level, w hile it forces suppliers t hat have high production variability to have a



mean that is well below the MEPS level. The issue of using a UCL type approach for energy labelling declarations and for verification is considered elsewhere in this paper.

Given that assessment of a m ean value has significant problems from a compliance perspective, Australia and NZ deci ded in 2007 t o convert the AS/NZS 2005 M EPS value from an average val ue to a m aximum permitted energy. The process for thi s was set out i n detail in previous consultation processes associ ated with 2008 Regulatory Impact Statement (EES 2008) and t he AS/NZS4474.2-2009 revision implemented in 2010. The factor to conver t from an average to a m aximum permitted level within a defined produ ction variability is to increase the M EPS level by 6.41% . Under this revised MEPS level, no individual unit of a model is permitted to exceed the MEPS level.

The technical basis to covert a MEPS based on an average t o a maximum value is based on an assum ed production variability of 5% of energy (coeffici ent of variation) and then assum ing a practi cal limit under a normal distribution of 90% of the population being better than this limit. This is 1.282 times standard deviation to get the normal cumulative probability of 90% = 1.282 5% = 6.41% increase in energy values. Suppliers with a larger production variability will need to ensure that the m ean energy value of their products more than 6.41% below the adjusted MEPS level.



B.9 Summary of Test Method Conversion Factors used to Adjust MEPS

This section summarises the technical conversions for US MEPS levels to obtain equivalent MEPS levels for each group, taking into account the differences in test procedure.

Table 5: Test Procedure Conversion Factors for US MEPS to AS/NZS MEPS levels

AS/NZS

Group US Cat

US Field

factor

Amb US

°C

Amb

AS/ NZS

FF US

°C

FF AS/

NZS

FZ US

°C

FZ AS/

NZS

FF Adj

%E/K

FZ Adj

%E/K

Field

factor

Amb

Corr FF Corr FZ Corr

Av =>

Max Overall

1 3A 1 32.2 32.0 3.9 4.0 N/A N/A -5.0% N/A 1 0.993 0.995 1.000 1.0641 1.051

2 1A 1 32.2 32.0 3.9 4.0 -9.4 -6.0 -2.4% -4.1% 1 0.993 0.998 0.859 1.0641 0.906

3 1 1 32.2 32.0 3.9 4.0 -9.4 -12.0 -2.2% -4.0% 1 0.993 0.998 1.103 1.0641 1.163

4 2 1 32.2 32.0 3.9 4.0 -17.8 -18.0 -1.7% -3.0% 1 0.994 0.998 1.006 1.0641 1.062

5T 3 1 32.2 32.0 3.9 4.0 -17.8 -18.0 -1.7% -3.0% 1 0.994 0.998 1.006 1.0641 1.062

5B 5 1 32.2 32.0 3.9 4.0 -17.8 -18.0 -2.4% -2.7% 1 0.994 0.998 1.005 1.0641 1.061

5S 4 1 32.2 32.0 3.9 4.0 -17.8 -18.0 -1.5% -2.8% 1 0.994 0.999 1.006 1.0641 1.062

6U 8 0.85 32.2 32.0 N/A N/A -17.8 -18.0 0.0% -4.0% 1.176 0.996 1.000 1.008 1.0641 1.257

6C 10 0.7 32.2 32.0 N/A N/A -17.8 -18.0 0.0% -4.3% 1.429 0.996 1.000 1.009 1.0641 1.527

7 9 0.85 32.2 32.0 N/A N/A -17.8 -18.0 0.0% -4.0% 1.176 0.996 1.000 1.008 1.0641 1.257

Notes: FF is fresh food, FZ is freezer (or frozen compartment). The target freezer temperatures for Groups 2 and 3 (in blue) are under consideration and specific stakeholder comment on these temperatures is sought. Energy impact per degree of internal temperature change derived from analysis in Paper 3. The energy impact values for Groups 2. 3 and 4 were derived from Paper 3, but the overall value was split by compartment into the same ratio as for Group 5T (values shown in red). US field factors for separate freezers have been reversed out in the conversion. Ambient temperature correction is derived from the current IEC Part 3 draft (59M/35/CD) and is still subject to committee review. Overall adjustment factor in the value shown in column 5, Table 1 of the Regulatory Discussion Document.

Conversion factors for defrost i nterval (see B.2), temperature during defrost and recovery (see B.3) and hum idity map for ambient controlled anti-condensation heaters (see B.4) are not i ncluded in the table above as these are di rectly taken into account in the energy calculation for MEPS for each individual model.



Annex C – Mapping US Product Categories to AS/NZS Groups

C.1 Introduction

The following sections in this Annex set out the main features that are effectively given allowances under US 2014 M EPS and i t sets out proposals on how t hese are to be accommodated in AS/NZS 2015 MEPS in Australia and New Zeal and. The basis for most of these accom modations is set out i n Paper 2, whi ch was released in October 2011. It is important to note t hat the allowances noted in the US are i n fact provided through different MEPS levels for products in different categories with and without the particular feature.

C.2 Automatic Icemakers (Internal)

One common category of products i n the US are products wi th internal icemakers. The US test m ethod adds an annual energy consumption of 84 kW h/year as an allowance for the m aking of ice (this is in addition to the aux iliaries that m ay be required so that the product i s ready to make ice, which is required under both test methods). A test m ethod to measure the energy associated with making ice is under development in the US and in the IE C (will mostly likely be based on a proposal from the USA).

For these products in the US, the MEPS level is increased by a simple 84 kWh/year. As the new IEC test m ethod being adopted in Australia and NZ does not add any energy for making ice for these types of pr oducts, this feature can be ignored for the purposes of a MEPS allowance. See B.6 for further information.

C.3 Automatic Icemakers (Through the Door Dispensers)

A total of 3 categories for US MEPS envisage an automatic icemaker with a through the door dispenser. These are:

• US Category 5A (AS/NZS Group 5B)

• US Category 6 (AS/NZS Group 5T)

• US Category 7 (AS/NZS Group 5S)

There are also built in variants for US Categories 5A and 7 (but not Category 6). It i s also important to note that the US provi des no al lowance for through the door i ce service for any other category, i ncluding the equivalent to Group 7 (US category 9 = vertical frost free freezers).

As set out in Paper 2, the effective MEPS allowance for these features, after the 84 kWh/year for making ice is also removed, is as follows:



• Category 5A (AS/NZS Group 5B) = 68 kWh/year

• Category 6 (AS/NZS Group 5T) = 74 kWh/year

• Category 7 (AS/NZS Group 5S) = 52 kWh/year

Two options were considered with respect to a MEPS allowance for the through the door ice service:

Option 1: A flat 52 kWh/year for a through the door ice service for any Group that has this feature (i.e. not restricted to the 3 US categories).

Option 2: Specific group based al lowances as set out above, but wi th no al lowance for any other groups where the feature may be present.

The government’s preferred posi tion is Option 1 a nd this has been i ncluded in the Regulatory Discussion Document.

This allowance effectively replaces the current val ue for A wi for MEPS i n AS/NZS4474.2-2009. Note that this only covers through the door i ce dispensers – it does not apply to water only dispensers, so there is no change in application.

C.4 Built-in Products

A total of 11 categories for US 2014 MEPS cover built-in products. These are primarily the AS/NZS Group equi valents to 5T, 5B 5S and 7. The addi tional variants include with and without through the door ice dispensers as covered by the previous section.

The US definition of built in products is set out below:

Built-in refrigerator/refrigerator-freezer/freezer means any refrigerator, refrigerator-

freezer or freezer with 7.75 cubic feet (219 litres) or greater total volume and 24

inches (610mm) or less depth not including doors, handles, and custom front panels;

with sides which are not finished and not designed to be visible after installation; and

that is designed, intended, and marketed exclusively:

1) to be installed totally encased by cabinetry or panels that are attached during

installation, 2) to be securely fastened to adjacent cabinetry, walls or floor, and

3) to either be equipped with an integral factory-finished face or accept a custom front

panel.

It is proposed to adopt thi s definition in full for bui lt in products for the purposes of AS/NZS 2015 M EPS in Australia and NZ. The def inition of a bui lt in product is mutually exclusive from a compact product, which is defined as being less than 7.75 cubic feet (219 l itres or less), so smaller products are not el igible for this allowance. Note also that a product that has a dept h of greater than 610m m cannot be classified as a built-in product and are not eligible for this allowance.

Analysis in Paper 2 sets out the differences of the built-in MEPS levels. A total of 4 options were canvassed in that paper. While any of those options may be acceptable, a fixed allowance of 40 kW h/year for al l groups except Group 5S, whi ch is allocated 100 kWh/year would appear to be the sim plest solution w hile still following fairly closely the net effect of built-in categories under t he US M EPS levels. This is the



government’s preferred position and has been i ncluded in the Regulatory Discussion

Document.

C.5 Compact Products

Under the new US test procedure and US 2014 MEPS levels for the US, the previous definition of a com pact product has been changed. The previous height restriction of <910mm has been rem oved. So al l products that are 219 l itres or l ess are now classified as “compact” under US 2014 MEPS. Note this is based on total volume and not adjusted volume.

MEPS levels for compact products are general ly somewhat to a lot weaker than the MEPS levels for non-compact products (i.e. a product at 219 litres vs a product at 220 litres). This effectively creates a discontinuity in MEPS requirements at 219 litres. The approximate compact US 2014 M EPS levels for each of the applicable AS/NZS groups are illustrated together with the energy for pr oducts registered in 2011 i n Annex F.

From a pol icy perspective, this is an unattracti ve position as i t could encourage suppliers to reduce the si ze of thei r products (those that are cl ose to 219 l itres) in order to get a weaker MEPS l evel. For example, there is also no cl ear technical reason why a product that i s 220 could meet a specified energy limit but a product at 219 litres could only meet an energy limit that is 20% weaker.

Implementation of the various compact MEPS levels as current ly defined in the US regulation is not favo ured by governm ent. As such, no al lowances for com pact products have been included in the AS/NZS 2015 MEPS levels. This is an area where stakeholder comment is sought. Any subm ission to governm ent would have to be based on clear and compelling data and should be widely supported by industry.

C.6 Door Allowance

Under AS/NZS MEPS 1999 and MEPS 2005 (and in 2010) there was an allowance for additional doors where the num ber of exte rnal doors was m ore than the standard configuration specified for each group. Th is was an al lowance that was i ntended to partly compensate for the hi gher heat gai n from longer gaskets because the test method would not give any credi t for a reduc tion of user rel ated heat loads from an equivalent number of door openings that were spread over smaller compartments, as may occur during normal use.

There was detai led discussion on this issue set out in Paper 2 and these poi nts are not being repeated in this paper. The US has never had any speci fic door allowance (or anything equivalent). The original concept was to cover products wi th many small compartments, like those that may occur in Japan. However, the majority of products with additional doors regi stered for MEPS door allowances are now Group 5B wi th split doors i n the fresh food com partment (French doors). These types of addi tional doors will not reduce air exchange during nor mal use. These French door products are now com mon in the US and t he US 2014 M EPS levels for this category have taken this configuration into account.



On consideration of all aspects, no door allowance has been included in MEPS levels for 2015 in Australia and New Zealand.

C.7 Adaptive Defrost Allowance

Under MEPS 1999 and M EPS 2005 (and 2010) t here was a so cal led “adaptive defrost” allowance. This was i ntended to compensate for those products that coul d achieve long defrost intervals under the US DOE test procedure. Under the US test method these control lers are cal led long-time automatic defrost systems (they are called Variable Defrost under the IEC test method). These types of system s were permitted to have long defrost intervals for MEPS assessment, while the AS/NZS test assumed that in no circumstance could the effective defrost interval exceed 24 hours. The 5% adaptive defrost al lowance was an imperfect attempt to correct for these differences. The allowance was not included in energy labelling but did allow products that would otherwise just pass US MEPS be sold in Australia and New Zealand when tested to AS/NZS4474.1. Further discussion is included in B.2.

Given that the new IEC test method being adopted has m uch greater flexibility w ith respect the handling of defrost intervals in the energy calculations and that for MEPS assessment, a defrost i nterval that i s broadly harmonised with the US approach i s being used, there is no longer a need to include the adaptive defrost allowance within the MEPS definition.



Annex D – Performance Considerations when Adapting US MEPS Levels

D.1 Introduction

The main focus of energy pol icy is to i nfluence the m arket so the supp liers provide products that are m ore efficient and therefore use less energy for a gi ven task. The definition of energy efficiency is the amount of energy used per uni t of energy service delivered to the end user. In the case of refr igerators, the energy service is quite well defined – each com partment of a defi ned type has to be capabl e of m aintaining temperatures within an acceptable range under a wide range of operating conditions. So as long as the product can dem onstrate adequate performance to achieve these requirements, the energy service is assumed to be delivered on a continuous basis.

This section provides a brief discussion on capacity related performance requirements in the IEC standard and the impact that these may have on the energy consumption of products in the context of stringent MEPS levels. It also briefly discusses the issue of humidity and how thi s can i mpact on energy consum ption of products. Thi s is background information only and no speci fic adjustments for these factors are included in the regulatory proposal set out in the Regulatory Discussion Document.

D.2 Capacity Performance Requirements

Under the existing AS/NZS4474.1 performance requirements, there are two tests that are mandated that i nfluence the design of re frigerators. These are the Tem perature Operation Test and the Pull Down Test.

For the Tem perature Operation Test the product i s operated in a wi de range of ambient temperatures (10°C to 43°C). The freezer i s filled with test packages and the fresh food compartment is empty. To pass this test requirement, the product must be able to m aintain suitable internal temperatures simultaneously in all compartments. Where necessary, the control s may be adj usted to achi eve this condition in each ambient temperature. This is a basic test that proves that the product is fit for purpose. This test is very similar (and equivalent) to the IEC Storage Test, whi ch is included in Part 2 of the new IEC dra ft standard and is proposed for use in Australia and NZ. The new IEC test i s somewhat simplified (by use of a si ngle test package si ze), but the basic elements remain comparable. It is important to note that the AS/NZS test was originally based on the ISO Storage Test, and this test has been i n widespread use around the world for many decades (although the required ambient temperature range varies by region).

For the Pull Down Test the product is left off with the door open in an ambient of 43°C. The product i s then swi tched on, the doors closed and the i nternal temperature of each compartment has to reach a defi ned value within a period of 6 hours. W hile this test is not intended to repl icate any form of “normal use”, i t has been found to be a



very reliable indicator that the product has adequate refrigeration capacity to process significant user loads and to cope with hot operating conditions. It is likely that this test will form part of the IEC performance standard.

Both of these perform ance tests are i ntended to ensure that the product works adequately under m ore adverse operati ng conditions and has suffi cient capacity to service normal user needs. It i s important to note that fai lure to operate adequatel y, even for short periods, w ill mean that com partment temperatures may be too w arm (leading to food spoilage, thawing of frozen food and allowing dangerous pathogens to grow) or i t may mean that unfrozen food m ay be destroyed by freezi ng. Failure to maintain adequate and safe operati ng temperatures during the wide range of typi cal use

2 would be total ly unacceptable to consum ers. The current req uirements in the

performance standard m ean that al l products can in fact m eet these basi c user expectations, so thi s provides a strong level of consum er protection and product comparability.

The impact of compressor capacity reductions are well known and w ell documented. The advantage that a vari able output compressor has at l ower ambient temperatures is clear and is derived from its ability to reduce com pressor output. E ffectively, the reduced flow of refri gerant lowers the temperature gradients (and tem perature differences) across the condenser and evapo rator. A sm aller total temperature difference between the condenser and evaporat or results in a sm all increase in operating efficiency of the compressor. Research testing shows that this impact could result in an energy reduction of about 2% to 8% for each 10% decrease in compressor capacity. To meet the above performance requirements (pull down and storage tests), at the energy test condition under AS/NZS4474.1, the system is effectively required to have plenty of spare capaci ty. In the absence of such per formance requirements, test energy could be reduced by a significant margin by reducing compressor capacity.

In the US, there is no mandatory requirement under the US DOE regulation to conduct any performance tests such as the Pul l Down Test or the Storage Test, even though similar tests are i n the AHAM industry standard as advisory tests. It i s ironic that the Pull Down Test w as in fact derived fr om the U S when energy labelling first commenced in Australia in the mid 1980’s, but it is not mandated in the US as part of their efficiency program. This is not to suggest that products i n the US have no reserve capacity at the energy test condition. But with such stringent MEPS levels like those proposed for 2014 in the US and 2015 in A ustralia and NZ, manufacturers will be looking for every option to improve energy consumption and this may be one area where products may be somewhat compromised if performance requirements are not maintained. It i s well known that p roducts from the US often have to be al tered to meet the performance requirements in AS/NZS4474.1.

In simple terms, retention of the perfo rmance requirements in AS/NZS4474.1 as part of the new IEC test method in Australia and NZ will mean that suppliers must provide adequate refrigeration capacity. The absence of such a requirement in the US means that all products that m eet requirements in the US woul d not automatically meet the

2 In this context, a wide range of typical use would in clude variations in ambient temperature as well as

processing requirements for cooling food and dealing with door openings.



same requirements here (t hey may pass M EPS but may fail the performance requirements).

This is an issue that is recognised, but no adjustment to MEPS levels to take this into account is proposed.

D.3 Humidity Requirements

Many parts of Austral ia (and to som e extent NZ) have rel atively high humidity levels (noting that the m ajority of the popul ation in Australia and NZ l ive on the coastal fringe). This means that products have to be designed to adequately deal with these conditions in order to provide acceptable operation.

There are two aspects of hum idity that can affect the energy c onsumption of refrigerators. The first is humidity in the ambient air surrounding the cabinet – external humidity. The second i s dealing with internal humidity that accum ulates on the evaporator during normal operation – internal humidity.

D.3.1 External Humidity

Some parts of the refri gerator external surface tend to be si gnificantly colder that the surrounding ambient air temperature

3 due to steep heat gradi ents around areas that

are difficult to insulate – this is usually around the door seals and the m ullion. In the absence of any m easures to deal with ambient humidity, moisture in the ambient air can condense on these parts of the refri gerator when the surfac e temperature falls below the dew poi nt. This leads to water dropl ets forming on the cabi net and can mean water can stream down the si des and onto the fl oor. This is clearly unacceptable to users.

To deal with this, most refrigerator designers divert a sm all part of the com pressor output and pi pe this around the areas where m oisture is likely to accu mulate (so called hot gas anti-condensation heaters). This system is self regulating in that under hot conditions, the compressor works hard and the heat put i nto anti-condensation is increased – thi s is good as the tem perature gradients are l ikely to be h igher and condensation more likely under warm er conditions. This process i s effectively using the heat being rejected to the ambient room for an addi tional task. The probl em with this type of desi gn is that operates cont inuously and cannot be turned on and off in accordance with the prevaili ng ambient humidity conditions. Inevitably, some of the anti-condensation heat piped around the m ullion will leak back into the cabinet via conduction, so there is a small energy penalty.

To deal with local ambient humidity in Australia and NZ, vi rtually all products use hot gas pipes around both the fr eezer and the fresh food co mpartments. US desi gns typically only have hot gas pi pes around the freezer com partments (possibly due to lower typical humidity conditions).

3 Apart from skin condensers when the compressor is operat ing, all external surfaces of the refrigerator

will have a surface temperature that is less than ambient temperature. Better insulation means that the surface temperature is closer to the ambient temperature.



An alternative to using hot gas anti-condensation would be the use of electric heaters. These could be controlled by ambient temperature and humidity sensors so that they only operate when required. They are already used for some configurations where it is not possible to pipe hot condenser gas (e.g. French door models as noted previously). However, this approach is not likely to be routinely favoured by designers as this sort of heater has to be em bedded into the cabi net wall and i f they fai l, they cannot be replaced, so the product would have to be scrapped.

D.3.2 Internal Humidity

During normal use, ambient humidity from the room finds its way into the refrigerator compartments. Humidity ingress comes from door openi ngs (ambient water vapour) and also there is water vapour emitted from fruit, vegetables and liquids stored in the refrigerator. There i s also ingress of ambient external humidity during closed door operation. As the compressor turns on and off, the compartment air cools and w arms slightly – the ai r expands and contracts i n response (so cal led “breathing”), which draws in some humidity from the surrounding ambient air with each cycle.

Internal humidity tends to m igrate to the coldest part of the com partment, where i t typically condenses as l iquid (if the surface is above 0ºC) or m ay form frost i f the surface is below 0°C (i .e. on a freezer wall or on an evaporator). For frost free products, which predominate the m arket in Australia and NZ, al l compartment air is cooled when i t is forced to fl ow across a remote evaporator (thus rem oving humidity from surfaces in the refrigerator and freezer, hence the term frost free).

Evaporators generally have closely spaced fins to maximise the surface area of the evaporator, which improves the heat transfer rate to the com partment air that i s circulated across the evaporator.

For a frost free evaporator, the fi rst air to hit the cold evaporator is the most humid, so much of the moisture in the air forms frost (sublimated water vapour) as i t initially hits the evaporator. Thi s frost form s on the evaporator fins. As m ore and m ore frost accumulates, the remaining space between the fins reduces and the air flow becomes restricted. The evaporator eventually needs to be defrost ed before the ai r flow is completely blocked. To spread out the ti me between defrosts, the initial fin spacing is usually somewhat wider. In low humidity environments, the remaining fin spacing can be close to m aximise total surface area of the evaporator. In hi gher humidity environments, the best design is for the fin spacing to only gradually get closer in each subsequent row (so cal led cascade evaporator design) as not al l humidity in a humid environment is deposited on the fi rst row of fins (tropicalised evaporator). This design greatly increases the interval between defrosts during normal use but i t does sl ightly reduce the overal l heat transfer capaci ty of the evaporator and thus the apparent operating efficiency for the energy test.

While products i n Australia, NZ and Asi a almost exclusively use tropicalised evaporators, these are generally not used in the USA.



D.3.3 Discussion

At this stage there i s not di rect test to indicate actual performance for these parameters under hum id conditions in the IEC standard. The IEC does have a sweating type test (for exter nal condensation), but this is quite new (the ol d test has been heavily modified with little development testing) and there is little experience with it to date. So at thi s stage, there is no proposal to mandate this test in Australia and NZ (this does not deal with internal humidity in any case).

There is nothing to stop suppl iers using standard (non-tropicalised) evaporators i n their products. These will probably perform quite well in the energy test (where there is low ambient humidity and no arti ficial humidity load), but in the field the performance could be qui te poor, i n that the actual defrost interval may be very short. Thi s is unlikely to be refl ected in the IEC test m ethod at this stage (al though such an effect should be captured un der the declaration of the value for td32-min in Annex D, which is the shortest defrost i nterval under t he most adverse operati ng condition – high humidity load). But even i f this value is declared accurately, this may not be reflected in the calculation of energy f or MEPS, which currently proposes t o use US def ault values for defrost intervals.

In summary, products in the Austral ian and NZ m arket need to adequatel y deal with significant humidity during normal operation. Most suppliers deal with humidity adequately, but there ar e not real ly definitive tests to ensure that perform ance is adequate for all products. Product designs that deal with humidity are likely to have a small energy penal ty. While local suppliers are l ikely to conti nue to ensure thei r products have adequate field performance, there w ill be the tem ptation to degrade humidity performance in order to m arginally reduce energy consum ption during the energy test.



Annex E – Technical Background for Energy Labelling

E.1 Introduction

Under the new IEC test m ethod, there i s a uni que opportunity to re -examine the energy calculation for refri gerators and freezers and move this to be a val ue that i s closer to that expected val ue during normal use. This is important, as suppliers focus on the energy label value and attempt to do what i s possible to optimise this value in their product desi gns. It i s well understood that the current energy test i n AS/NZS4474.1 (32°C ambient, closed door with no processing load) is far away from normal use and there i s a real risk that pr oducts optimised for that condi tion alone may not be very efficient during more usual operating conditions represented by lower ambient temperatures and with some user related processing loads. The impact of the test method on refri gerator energy cons umption should not be under esti mated. A study by Pradeep Bansal (2002) found t hat household refrigerators performed best under the test procedure for whi ch they were desi gned. Understandably, manufacturers will care little about the en ergy consumed by a refrigerator during normal use if this is never measured or assessed.

The IEC sets out measurement approaches for the following parameters:

• Energy consumption at an am bient temperature of 32°C – more or l ess the same as the current energy AS/NZS4474.1 test but wi th different compartment temperatures as defined by the IEC st andard (freezer at -18°C and fresh food at +4°C).

• Energy consumption at an am bient temperature of 16°C – this is at the l ower end of norm al household operation (with the same internal compartment temperatures).

• Measurement of processi ng efficiency – this is a test that determ ines the additional energy requi red to removed a known amount of heat energy i nside the compartment (in the form of cool ing warm bottles of water and m aking of ice cubes).

The IEC envi sage that these 3 el ements can be com bined at a regi onal level to provide a good estimate of the energy consumption during use of a typical or standard consumer (if the key parameters relating to such a consumer are known at a r egional level). As with energy labelling approaches fo r all products, it is never possible to represent every consum er on the energy l abel. But i t is important that the val ues selected for energy labelling broadly represent t he range of likely use by asses sing and weighting the key components that make up typical energy consumption.

For refrigerators and freezer s, the usage rel ated aspects can be si mplistically characterised as changes in i ndoor ambient temperatures (that will to some extent be



affected by cl imate and bui lding shell) and user acti ons such as door openi ngs and cooling of food and drink loads.

The following sections discuss current knowledge on each of these el ements. This is followed by proposals for a num ber of opti ons to com bine the IEC el ements for the purposes of energy labelling. T hese have been included in the E 3 Regulatory

Discussion Document to be implemented as part of the regulatory changes in 2015.

E.2 Current System for Energy Measurement

Under AS/NZS4474.1 there i s only a single energy consumption number that can be determined – thi s is the energy consum ption measured in a very warm room (32°C ambient) with no door openi ngs or other ty pes of processi ng load. The i mpact of defrosts are i ncluded in the ener gy value, but at a m aximum defrost interval of 24 hours is assumed. This energy value is used for determination of MEPS and also for energy labelling. This is intended to a llow consumers to com pare the energy consumption during use.

When typical consumers are tol d how refri gerators are currently tested, they are universally amazed that this value could in any way represent normal use in the home. It is like using the fuel consumption of a car while climbing a large hill as a basis for estimating normal city driving. The measured value can be rel iably compared across products, but it is not likely to tell us m uch about what the refrigerator or freezer w ill consume when subj ected to m ore typical operating temperatures and som e user related loads.

This effect i s reflected in the few end use measurement studies that have been conducted. These show that the m easured energy consum ption is highly variable between houses (as m uch as ±40% from the nominal label value). To som e extent this will be driven by variability in cons umer use and substa ntial changes in indoor ambient temperatures, but it w ill also be because the current energy test translates poorly to normal use conditions.

For example, it is possible for 2 hypothetical refrigerators to measure the same energy consumption in the current energy test. The fi rst may have thi ck insulation with an average to poor effi ciency compressor and refri geration system. The second m ay have relatively thinner insulation but wi th a high efficiency refrigeration system. In a test report under AS/NZS4474.1 they may look identical with respect to energy. But under real use condi tions with reduced am bient temperatures and a si gnificant amount of processing l oad, the second refri gerator will use substantially less energy. Under the current labelling system users are told that they are the same.

The logic of using an elevated ambient temperature to compensate for usage related aspects of refrigerator energy consumption appears to have ori ginated in the USA i n the 1970’s, although none of the published papers really provides strong evidence to support this approach i n terms of provi ding an accurate overal l result for di fferent products. The main objective was to have a test procedure that was fast, si mple and reproducible (which is clearly very i mportant). It i s now widely accepted that attempting to simulate actual usage patterns (though door openi ngs and many small user related loads) is almost impossible in terms of a practi cal test procedure. These



types of m easurements tell us l ittle about the i mpact of these usage related components unless they are carefully disaggregated in the energy measurements.

Detailed investigations over the past decade has illustrat ed that the change in energy consumption in response to changes i n ambient temperature is highly variable at a model level. So an elevated ambient temperature is unlikely to provide a reliable proxy of user related loads in a static energy test.

Under the new IEC test m ethod we now have the tools to estimate how much energy refrigerators are l ikely to use duri ng normal use by exam ining the com ponents that effect energy consum ption as m easured in the IEC standard and addi ng these together in a representative way that reflects local conditions in Australia and NZ. The labelling proposal set out in this paper and in the E3 Regulatory Discussion Document is to take a first step in this direction.

E.3 Indoor Ambient Temperatures

The majority (but by no m eans all) refrigerators and freezer s operate i ndoors in conditioned spaces. Indoor temperatures vary over a smaller range when compared to outdoor temperatures, due to the am eliorating effects of the bui lding shell itself and the use of indoor space conditioning equipment.

In 2009, CSIRO and the Bureau of Meteorology measured indoor temperatures in more than 40 hom es in Melbourne (CSIRO 2010) for l ong periods that covered summer and wi nter. The data shows that the average i ndoor temperature for the selected homes was 21.2°C wi th a standard deviation of 2.0K, wi th the l ower 10% reading in winter averaging 15°C (at 6am ) and the upper 90% in summer averaging 27°C. The indoor average humidity was measured at 50%RH.

Figure 1: Measured Indoor Temperature Distribution for 40 Homes in Melbourne

Source: CSIRO 2010.



This suggests that i n simplistic terms, the indoor temperature distribution in homes could be reasonably represented by a normal distribution as follows.

Figure 2: Likely Annual Indoor Temperature Distribution in Australian Homes

The mean temperature is likely to vary a bi t by climate, but it is a useful starting point for examining energy labelli ng options. It w ould be expect ed that m ore efficient building shells may have a narrower di stribution (smaller standard devi ation), while poor building shells may have a wi der distribution (the CSIRO study was a representative mix of the stock, so is probably typical).

CSIRO are currentl y undertaking indoor temperature measurements in some 500 homes around Austral ia over at l east 1 year (CSIRO 2012). The assum ed temperature distribution data used for the energy la belling proposal can be adjusted once some preliminary results from this project become available. This will provide a better reflection of condi tions in different climates and for di fferent building shell constructions.

E.4 Response of Refrigerators and Freezers to Ambient Temperature

While the IEC test method will deliver an energy value for an am bient temperature of 32°C and 16°C, i t is important to understand how a refri gerator typically responds to ambient temperature to obtain a better i dea on how to use these two values can be used to get a better esti mate of the energy consumption component under a range of ambient conditions.

The measured static energy consumption of a refrigerator or freezer (without any user interaction) is made up of two components – the steady state power consumption and the incremental energy for defrost and re covery. It i s now wel l established through



extensive testing that the i ncremental energy for defrost and recovery i s relatively constant for di fferent temperature control settings and even for di fferent ambient temperatures on the one refri gerator (this can vary sl ightly for som e models, the assumption of a constant val ue is reasonable for the vast m ajority of m odels). The main defrost characteri stic that changes wi th ambient temperature is that defrost intervals tend to becom e longer at lower ambient temperatures (which is reflected in the IEC test method).

The steady state power of all refrigerators and freezers exhibit a very strong response to changes in ambient temperature. While this is well known, this important attribute has not been taken in to account in prev ious energy labelling schem es or in any previous test procedures (except for the JIS test method). The following equation sets out the main factors that drive energy for a single compartment refrigerator or freezer:

Where:

P is the (expected) steady state power consumption

U is the overall average U value (insulation) of the cabinet walls

A is the surface area of the cabinet walls

Ta is the average ambient temperature around the refrigerator

Ti is the internal average temperature of the refrigerator

COP is the (m arginal) operating coefficient of perform ance (efficiency) of the refrigeration system.

Clearly the val ue of i nsulation (U) and su rface area (A) rem ain constant (i gnoring minor insulation deterioration over ti me) once the refri gerator has been constructed (but every refrigerator is different). The internal temperature also (should) remain fairly constant for a gi ven compartment type (i f the te mperature control system works properly). So the steady stat e power i s more or l ess a l inear function of am bient temperature divided by COP. The COP of real compressors also tends to be fai rly linear with changes in ambient temperature (condensing temperature) (assuming the internal compartment and hence evaporator tem perature is fairly constant for a gi ven design).

There are m any other sm aller factors t hat affect the energy consumption of a particular refrigerator (especially heaters and other auxiliaries and things like compressor operating losses, start-up l osses and vari able speed dri ves), but these two factors are the most significant.

So the general shape of power consum ption in response to changes i n ambient temperature tends to rem ain fairly consistent across di fferent products because the heat gain through the insulation is linear with changes in ambient temperature and the efficiency of the refri geration system is also linear. A curve resul ts because a l inear change in the denominator (COP) creates a non linear overall effect.



Figure 3: Published COP data for R600a Compressor

Source: www.embraco.com Note that the evaporator temperature is somewhat colder than the coldest compartment temperature and the condenser temperature is somewhat warmer than the ambient temperature.

Figure 4: Typical Steady State Power Response to Ambient Temperature

Source: Energy test data supplied by Choice, reference DX43.4. Note that internal temperatures are not adjusted to energy target temperatures, but these effects are very relatively small if compartment temperatures are relatively stable. Note that there is a 400% increase in energy from an ambient of 10°C to 40°C in this case.



Under the IEC test m ethod we obtain an estimate of the energy consum ption at each end of the tem perature range that is of most interest during normal use (i .e. at 16°C and 32°C). This is a massive improvement over the previous test method as we now know that the steady state curve must pass through t hese 2 points. The problem is that the exact temperature response can be different for each model (driven by factors such as size and temperature of compartments, insulation thickness and compressor performance as well as auxiliaries and other fa ctors). The ratio of energy at 16°C to 32°C ranges from as little as 0.25 to as much as 0.60, dependi ng on the Group (m ix and temperature of com partments) and the m odel configuration. However, i t is possible to make an estimate of the l ikely ambient response curve from the values at each ambient temperature because reasonable estimates of the main parameters that will affect energy can be m ade (mainly compartment insulation and changes in compressor efficiency).

Previously, only energy data at 32°C was available, so there was no possible basis for estimating energy consumption at any ot her ambient condition (you cannot esti mate the slope of a l ine from a si ngle point). It was wel l known that the energy sl ope in response to changes i n ambient temperature of different models varied significantly. This is well illustrated in the following figure for 3 different Group 1 models.

Figure 5: Comparison of steady state power at different ambient temperatures – Group 1

For the example refrigerator illustrated in Figure 4 abov e, the temperature distribution bins in Figure 2 can be wei ghted by the expected steady state power for each bi n. This is set out in Table 6 below.



Table 6: Weighting of Steady State Power with Expected Temperature Bins

Temp Bin Av °C

Steady State

W (curve)

Frequency Distribution Temperature

Weighted Power W

15.5 24.3 0.003 0.084

16.5 25.3 0.010 0.264

17.5 26.4 0.031 0.808

18.5 27.5 0.071 1.942

19.5 28.9 0.127 3.661

20.5 30.3 0.179 5.413

21.5 31.8 0.197 6.276

22.5 33.5 0.170 5.702

23.5 35.3 0.115 4.060

24.5 37.2 0.061 2.264

25.5 39.2 0.025 0.989

26.5 41.4 0.008 0.338

27.5 43.6 0.002 0.090

28.5 46.0 0.000 0.022

Notes: Steady state curve fit from tested data for unit DX43.4.

Temperature distribution bins from Figure 2.

The weighted average power for thi s model for the assum ed ambient temperature distribution is about 32 W, which is equivalent to the energy at about 22°C. Given that the power response curve get s steeper at warm er temperatures, the average energy is expected to be at a tem perature that i s slightly warmer than the m ean ambient temperature given by the normal distribution (21.2°C), although this difference is fairly small as the curvature is not all that large across this temperature range.

When we look at the steady state power values for 16°C and 32°C (i n this case 24.8 W and 55.4 W respectively), we can show that we could weight these values by about 0.75 and 0.25 respectively to get a reasonable estimate of the energy at 22°C.

These ratios were al so checked for a sel ection of other groups (e.g. Group 1 al l refrigerators and Group 7 – s eparate freezers as wel l as a number of other Group 5 products) that are illustrated in the following figure.



Figure 6: Ambient temperature response curves for a range of products

Source: Choice test data. Group is shown in product reference.

Even for the range of Groups shown i n Figure 6 and for the di fferent ambient response curves, a wei ghting of 0.75 fo r 16°C power and 0.25 for 32°C power gi ves an average power value that is very close to the temperature weighted average power for all of these products (when the m easured ambient response curve is used) for the assumed normal distribution is in the range 21°C to 22°C.

To examine the impact of assumed ambient temperature distribution on these values, 2 additional indoor temperature regimes were consi dered. These were an i ndoor ambient mean temperature of 22.4°C (with a standard dev iation of 2K) and an i ndoor ambient mean temperature of 23.4°C (with a standard devi ation of 2K). Exam ination of the ambient response data for som e 20 different cabinets in Group 1, Group 7 and various Group 5 products showed that the fol lowing weightings for test results at 16°C and 32°C gave good representative average energy values:

Ambient 21.4°C: weighting of 16°C value =0.75, weighting of 32°C value = 0.25



Clearly the weighting for each am bient temperature is quite sensitive to the average indoor ambient temperature. While these weightings appear to gi ve quite good estimates of the wei ghted average tem perature, it may be possi ble to refi ne these slightly by Group (al though the di fferences at a Group l evel appear to be onl y minor based on initial data analysis).

This approach is a significant change from the previous scheme where only energy at 32°C was considered as the basis for energy labelling. Given that there are a range of



possible climates to be covered, it may be possible to provide climate specific data on the detailed part of the websi te to refl ect different indoor ambient temperatures in different regions (although this is not proposed as a core part of labelling).

If accounting for the energy i mpact of av erage ambient temperature was the onl y element of actual use that needed to be considered in developing a val ue for the energy label, then thi s type of functi on for com bining the resul ts for each am bient temperature would be qui te satisfactory. However, a substanti al part of the energy consumption during normal use com es from user interaction with the refri gerator or freezer. This is discussed in the following section.

E.5 User Interactions with Refrigerators and Freezers

It is well understood that refr igerators and freezers do not operate with closed doors during normal use i n real homes. Users access compartment(s) by m eans of the doors provided and food and dri nks are placed in the refrigerator and i tems are also removed and repl aced. As a consequence of door openi ngs, cool air inside the refrigerator falls out onto the fl oor and warm ambient air from the room displaces the air that cascades out (col d air is heavier than warm air). The ambient air in the room will also contain hum idity (water vapour), much of which will end up on cold internal surfaces like the evaporator or on the com partment walls. These i nteractions are relatively complex and to som e extent qui te variable over ti me within a si ngle household and m ay be qui te different between househol ds. The l evel of user interactions will also be some extent dr iven by the num ber of householders that use the refrigerating appliance and the num ber (and ranking of each appl iance) and the size of the appl iance. While there are m any different elements to user rel ated loads, these usage elements all appear as net heat l oads that the refrigerator has to extract from the cabinet.

Unfortunately, because these i nteractions are fairy complex, they are general ly not well documented. There i s no si mple way to calculate these heat l oads based on assumed actions (although psychrometrics is a well established branch of science and reasonable approximations can made for a set of defined actions and using a range of specific assumptions).

Research on the issue of user interaction is being undertaken by Lloyd Harrington and data for a cross secti on of households and re frigerators should be avai lable by l ate June 2012 for consideration at the public forum.

Preliminary data shows that usage related loads are significant. For large refrigerators this could account for 300 Wh per day of heat load (averaged over a year). Depending on the efficiency of the refrigeration system, this could add about 75 kW h/year to 150 kWh/year to the total energy consum ption. Given that the MEPS levels for large refrigerator-freezers are now of the order of 400 kWh/year (at 32°C ambient), this user related energy could be less than 20% or as much as 40% of the total energy at 32°C, or well over 50% of the total energy for a composite energy value made up of 16°C and 32°C as set out above.

As a discussion point, an initial estimate of user rel ated processing load is given as 0.75 Wh per day per litre of fresh food volume and 0.25 Wh per day per litre of freezer



volume. This means that a 500L refri gerator-freezer (350 litre fresh food and 150 litre freezer) would be assum ed to have a com parative processing load of 300 W h/day while a 100L bar refrigerator would be subjected to a processing load of 75 Wh/day. A 300L separate freezer would also be subject to a processing load of 75 Wh/day.

To usefully include this value into the composite energy consumption that has been estimated for the expected am bient temperature range, the esti mated comparative user heat load has to be di vided by the expec ted marginal operating efficiency of the refrigeration system. A higher operating e fficiency (COP) will mean less energy consumed by the refri gerator to rem ove the assum ed amount of user rel ated processing load.

There are a number of possible approaches to estimate the processing efficiency. The most obvious approach woul d be to under take a di rect measurement of the processing efficiency in accordance with Annex G of the new IEC test method. Ideally, this should be done at an am bient temperature of 16°C and 32°C. An average val ue at these two tem peratures would provide a qui te accurate esti mate of processi ng efficiency during normal use. However, th is could be considered an onerous testi ng burden as the test at each am bient temperature adds about 24 hours of test ti me to a standard energy test.

Some work is under way to develop a faster method to measure processing efficiency, as an alternative to the current IEC test. So it may be possible that such an approach may be finalised later in 2012. So this could be considered if available.

Another alternative may be to use i nformation on the rated com pressor efficiency as the basis for esti mating the processi ng efficiency. Further i nvestigations into that approach are still required befor e its suitability could be fu lly assessed. P reliminary data suggests that a scal ed value of t he rated com pressor COP for the CECOM AF test condition is likely to provi de a reas onable estimate of the practi cal processing efficiency. The ASHRAE test condi tion could also be used i f the CECOMAF value is not available (but the rati ng conditions for ASHRAE are qui te optimistic and woul d need to be scal ed down m ore than the CECOM AF value). Some adjustment (downgrading) to both these rated val ues is likely to be requi red as the practi cal efficiency of the refri geration system is always somewhat worse that the rated compressor efficiency due to a range of l osses and inefficiencies in practical systems and normal operating conditions are not at the rating point. Any option based on such a value would need to be conservative if a measured value is not provided (to provide incentive to measure the value).

In all cases, where a measured or rated value is not known or not avai lable, a default value could be used for the purposes of energy labelling calcul ations. The default value is likely to be very con servative (i.e. significantly lower than would be obtained through measurement). A val ue of about 0.5 i s likely to be l ess than the m easured value for any avai lable refrigeration system. A supplier may elect to do thi s for small low cost products where the energy rating is not considered to be i mportant and the testing costs are an issue (or the processing load is small, e.g. a small freezer).

The application of the l oad processing approach i s quite simple. The assum ed processing load (which is proposed as a function of the com partment type and



volume) is divided by the assum ed processing efficiency as set out i n the IEC standard Part 3 Clause G.5.5:

Where:

Eprocessing is the additional daily energy consumption of the refri gerating appliance in Wh/day to process the user related load Euser

Euser is the user related heat load equivalent entering the refrigerator in Wh/day arsing from normal usage (specified as a function of volume and compartment type)

Efficiencyload,ambient is the l oad processing efficiency at the speci fied ambient temperature in accordance with Annex G in Wh/Wh (dimensionless).

Alternatively a value based on the scal ed compressor rating or a defaul t value could be used for Effi ciency in this calculation if this approach was deem ed to be acceptable.

It is possible to spl it this user l oad into seasonal components and then wei ght the processing efficiency evenly by season, but this is a complicated procedure that w ill give little improvement in the overall estimate of user energy consumption. While the seasonal variation in user l oads is likely to be l arge (summer is 2 to 3 ti mes larger than winter in terms of user processi ng load), the expected change i n processing efficiency is relatively small (processing efficiency is likely to be onl y 20% better i n winter than in summer) so in fact using only a single value for processing efficiency based on a m easurement at 32°C m ay provide quite satisfactory overall results and will reduce testing burden, given that the assum ed processing load is used for comparative purposes.

The value of Eprocessing above i s multiplied by 365 (and di vided by 1000 where applicable to convert i t to kWh/year) and then added to the wei ghted average energy data for different temperatures (see E.4).

E.6 Rewarding Flexibility of Operation

As canvassed i n some detail in Paper 2 (Appendix A), i t was noted that the IEC internal target temperatures are probably not the temperatures we want consumers to actually select and use duri ng normal use. The IEC target tem peratures for energy were agreed as part of an i nternational harmonisation process and they were negotiated as part of an i nternational compromise. In general terms, the freezer temperature of -18°C (average) is generally regarded as quite cold and w ill result in significantly higher energy consum ption compared to the curr ent AS/NZS target temperature of -15°C. In r ound figures, it is expected that thi s 3K reducti on in temperature will result in a 10% to 15% increase in energy consum ption. From an energy policy perspective, this is not desirable (as -15°C is regarded as a satisfactory storage temperature for most items).



Similarly, the IEC target tem perature for fresh food com partments is +4°C. Thi s is probably slightly warmer than would be generally recommended for the safe storage of perishable foods such as m eat, dairy and fish. A temperature of +3°C or col der is generally regarded as preferabl e for these types of i tems. The energy i mpact of a reduction in fresh food temperature by 1K is generally small (a few % for refrigerator-freezers, but up to 5% for Group 1).

There is absolutely no question that Australia should measure and declare the energy consumption of al l products at the standardi sed IEC tar get temperatures at each standardised ambient temperature. This is the f oundation of i nternational harmonisation. Failing to m easure and record inform ation at those conditions w ill mean that Austral ia and NZ are i solated in terms of test data and i nternational comparisons and cooperation, which undermines the value of harmonisation.

However, it may be possi ble to provi de a reward to products that have good temperature control and flex ible operation under the ener gy labelling schem e. This could be achieved by al lowing the measured energy consumption when operating at the more desirable internal target temperatures of +3°C and -15°C to be i ncluded in the overall energy consum ption calculation. It m ust be stressed that i f this was included as an option for energy labelling, that the data at +3°C and -15°C would be measured and declared in addition to the s tandard IEC target tem peratures of +4°C and -18°C.

The other advantage to thi s approach (i f adopted) is that i t would provide additional benchmarking and continuity with historical energy data that has been com piled over the past 25 years (at l east for those products where the suppl ier opted to include this additional data).

In any case, this additional test would be optional. If this concept is seen as desirable by stakeholders, then furt her work can be undertaken on how this value w ill be incorporated into the energy labelling scheme.

E.7 Adjusted Volume

One issue that is of particular interest under this revised energy labelling approach is whether we should continue to use adjusted volume for energy labelling. The concept of adjusted volume is a weighting factor that is applied to each compartment to reflect its relative temperature of operati on when com pared to a standard fresh food compartment. For exam ple, at an am bient temperature of 32°C and a freezer compartment at -18°C has a temperature difference between inside and outsi de of some 50K. The tem perature difference between the am bient and a fresh food compartment at +4°C i s 28K. So the rel ative temperature difference at thi s ambient temperature is given by the freezer adj ustment factor (FAF) = 50/36 = 1.7857. This is in fact proportional to the expected difference in heat gain if the compartments had the same insulation levels

4.

4 The heat gain is also a function of the external surface area of th e compartment, which is in fact

different to the compartment volume.



However, there are some interesting observations and revelations regarding this issue when additional information is considered.

Firstly, we know that physi cs tells us t hat the heat gai n into a com partment is a function of the tem perature difference and the insulation value of the com partment walls, as well as the surface area of the wa lls. When real products are examined, it is clear that manufacturers use a greater thickness of insulation for freezers than they do for fresh food com partments. This makes eminent sense because i f the i nsulation thickness was the sam e all over (thin), the heat gains into the freezer woul d be very large indeed and thi s would totally dominate the overall energy c onsumption of the product. Thick insulation all over woul d mean a si gnificant loss of usabl e volume inside the fresh food com partment for little appreciable reduction in energy consumption. As i t happens, m ost manufacturers tend to use about 50% to 60% thicker insulation for freezer com partments when com pared to fresh food compartments (at l east on refri gerator-freezers, where the rel ative thickness can be directly compared) (and which is the only product where using adjusted volume makes any sense at al l). So to som e extent normal product designs tend to com pensate or neutralise the impact of operating temperatures in different compartments (i.e. broadly reflect the FAF value).

The second i mportant issue to consi der is the fundam ental concept that underl ies adjusted volume. Calculating the te mperature difference between am bient temperature and com partment temperature only has rel evance if it is assumed that the ambient temperature during normal use i s also constant. Cl early this is not the case in real life. Now we have an energy determination at an ambient of 16°C and at 32°C (which are general ly considered to be at the hi gher and l ower end of norm al operation ambient temperatures). For a refrigerator-freezer operating at 32°C, the FAF is 1.79 (as shown above). At an am bient temperature of 16°C, the FAF = 34/12 = 2.8333. This suggests that at lower ambient temperature the relative heat gain into the freezer is much more important (as the relative temperature difference is much larger). So which value do we use for energy labelling? The change in relative heat gain into a freezer and fresh food com partment at different ambient temperatures is illustrated in the following figure.



Figure 7: Modelled Heat Gain into a Theoretical Refrigerator

To some extent energy testi ng at an ambient temperature of 32°C has m ade manufacturers concentrate m ore heavily on i nsulation levels in the fresh food compartments and l ess on the freezer as t he higher ambient temperature for the energy test overemphasises the heat gain into the fresh food com partment. Now that we are taki ng into account the energy consumption across a range of am bient temperatures (possibly with more emphasis on lower ambient temperatures), then this is likely to refocus the attenti on of designers to better optimise their products at lower ambient temperatures. Of c ourse the other desi gn constraint is compliance with MEPS, which will continue to be at an am bient temperature of 32°C as set out earlier in this paper.

As noted above, the use of adj usted volume only makes sense for products where there are several compartments operating at quite difference temperatures in the one appliance. Adjusted volume can provi de a tool to m ore fairly compare one product with a larger freezer and sm aller fresh food compartment with another product of the same total volume but wi th a smaller freezer and larger fresh food. To som e extent, using adjusted volume does not m ake any sense for those Groups that have on ly a single compartment that operates at a defi ned temperature (notably Group 1, and al l separate freezers Groups 6U, 6C and 7). But even within these groups it is possible to have additional compartments at di fferent temperatures under som e configurations. So it w ill probably necessary to retain som e form of adjusted vo lume calculation to enable energy labelling to fairly com pare a range of product configurations within and across Groups.

The current energy labelling function of volume to the power of 0.67 is intended to be broadly reflective of product surface area as a functi on of the unadj usted volume.



However the use of thi s power functi on on the adjusted volume does di stort this approach to some extent, so ways if normalising these effects should be examined.

Given that we are generally interested in the energy consumption of the refrigerator at or around an ambient temperature of 22°C to 24°C (where we expect refrigerators and freezers to spend much of their operating life), then selecting an ambient temperature in that range in order to calculate an energy labelling FA F appears to be m ost sensible.

There are several options that coul d be c onsidered. The fi rst would be cal culate a labelling FAF at an am bient temperature of 24°C – this is half way between the two test temperatures and would offer a good bal ance of the tw o test results utilised for energy labelling. The freezer FAF at this temperature would be 42/20 = 2.10

The second would be to cal culate the FAF for each ambient temperature and weight this in proportion to the weighting of the energy values used to calculate the CEC.

The third option would be to cal culate the FAF for the expected average i ndoor ambient temperature of 22°C. The freezer FAF at thi s temperature would be 40/18 = 2.22.

Each of these options will give a similar outcome. The first is perhaps the simplest and neatest approach and is the one recommended.

In terms of appl ying adjusted volume, a new term could be devel oped that coul d calculate a norm alised volume would bring the adj usted volume back to som ething closer to the unadjusted volume for the standard configuration. This could be done by assuming standard shares by com partment type for the 3 labelling categories: fresh food/freezer share of 90% /10% for l abel algorithm 1 (Group s 1, 2, 3), 70% /30% for label algorithm 2 (Groups 4, 5T, 5B and 5S) and 0% /100% for l abel algorithm 3 (Groups 6U, 6C and 7). A product that had a higher freezer share than the standard product share would have a sl ightly higher normalised total volume (and vice versa). The normalised volume would be much more reliable as a value to use in the existing labelling algorithm, which uses a function of volume to the power of 0.67.

E.8 Energy Labelling Algorithm

Given that there are substantial changes to the way energy is likely to be calculated, a firm proposal for a revi sed star rating system for 2015 has not been i ncluded in this technical support docum ent. It w ill be nec essary to gain broad agreem ent on the components that will be used for the C omparative Energy Consumption value before specific labelling equations can be developed.

It is envisaged that the broad approach used in the current energy labelling algorithm will be retained. The key features are:

• Grouping of products into 3 categories to allow comparison of like products:

Algorithm 1: Groups 1, 2 and 3 (typically single door, simple design);

Algorithm 2: Groups 4, 5T, 5B and 5S (two door refrigerator-freezers);

Algorithm 3: Groups 6U, 6C and 7 (separate freezers – all types).



• Retain current star rating range (2010 algorithm).

• Use same equation to calculate star ratings - similar geometric progression.

• Use of a function of volume to the power of 0.67.

• An ERF of 0.23 is likely to be retained.

• 3.5 to 4 stars for better products i n the short term after M EPS 2015 implemented.

• Have room for 7 to 10 stars i n the algorithm, but i t is not expected that these will be used in the short term – will give the revised algorithm a longer life than otherwise would have.

• Require testing of 3 products for registration purposes.

There are a range of factors that need to be taken into account when a new star rating algorithm is developed:

• The Comparative Energy Consumption value may be reduced by the i nclusion of the lower ambient temperature, but the overal l energy could be increased if processing load is added – an initial assessment of these effects will need to be undertaken to ensure that al gorithm is not too weak or t oo harsh (onl y the values of a, b and c in the calculation of BEC will need to be reviewed).

• MEPS impact in 2015 – it is expected that there will be up to a 30% reduction in energy consumption for some products as a result of new MEPS levels. It w ill be important to anticipate these affects and ensure that the l ikely impacts are taken into consideration.

• Use of new adjusted volume (Freezer Adjustment Factors) for energy labelling.

• Possible use of a normalised volume in lieu of adjusted volume to better reflect surface area function in the labelling algorithm.

One issue that could also be considered is whether the use of a UCL approach (upper confidence limit, like that specified in the US for declarations and verification) is useful for energy labelling declarations and verifi cation as part of the revised A S/NZS requirements.

It is expected that the energy lab el design will be largely unchanged. The only additional information that is being considered for inclusion on the energy label itself is information on the compartment volumes.



Annex F – Compact Product Figures

F.1 Illustration of Compact MEPS by Group

The following figures show current products in Australia and New Zeal and as of l ate 2011 with the estimate MEPS levels for 2015. The US levels for compact products are shown with the green l ine. Note that the MEPS lines have al l been converted to the AS/NZS4474.1-2007 test condi tions and the data points are the registered values under the current schem e, so the absolute values w ill not align w ith the M EPS proposals set out on the E3 Regulatory Discussion Document.

The figures are followed with some commentary on MEPS issues that may be relevant regarding each Group.

Figure 8: Indicative Impact of MEPS 2015 Group 1 – AS/NZS test method




Figure 12: Indicative Impact of MEPS 2015 Group 5T – AS/NZS test method

No products in Groups 5S and Group 5B fall into the compact size range.



Figure 13: Indicative Impact of MEPS 2015 Group 6C – AS/NZS test method

Figure 14: Indicative Impact of MEPS 2015 Group 6U – AS/NZS test method




F.2 Discussion on Compact MEPS by Group

The following dialogue provides some initial interpretation of the data i n the above figures and som e initial observations regarding compact MEPS discontinuities for each group. Stakeholder comment is sought on treatment of compact products.

Group 1: A majority of products in this Group are larger than the compact size. There are many products of al l sizes (include compact products) that exceed the non compact MEPS level by a considerable margin. On closer examination, many of these are high end European products that current ly have few sal es (and m any are not actively sold in Australia). It is noted that the Compact MEPS level for Group 1 i s relatively weak (i.e. close to the 2010 MEPS line).

Group 2: Most products in this Group fall into the compact category. There are many products that exceed the non com pact MEPS level by a consi derable margin in the smaller size. It is noted that the Compact MEPS level for Group 2 i s relatively strong (i.e. closer to the non com pact MEPS level; compact MEPS is about 30 kWh/year higher). Government’s preferred option is to have no compact MEPS for this Group.

Group 3: Products in this Group are evenl y split above and bel ow the compact size, although there are rel atively few products overall. Most products exceed the non compact MEPS level. It is noted that the Compact MEPS level for Group 3 is relatively strong (fairly close to the non compact levels; compact MEPS is about 30 kWh/year higher). Given that only two products in this Group would be affected by non com pact MEPS levels, government’s preferred option is to have no compact MEPS f or this Group.



Group 4: No products currentl y clearly fall into the com pact size range. There are relatively few products overall in this Group. The compact MEPS level for Group 4 i s weaker than the existing 2010 MEPS levels (i.e. very weak). No options for compact MEPS for Group 4 are being sought.

Group 5T: The compact MEPS level for Group 5T is very weak (sl ightly weaker than existing 2010 MEPS levels). Only eight products out of a total of 360 models in this Group currently clearly fall into the com pact size range. Governm ent’s preferred option is to have no compact MEPS for Group 5T.

Group 5B: No products currently fall into the compact size range (apart from 1 custom product). No options for compact MEPS for Group 5B are being sought.

Group 5S: No products currentl y fall into the com pact size range. No opti ons for compact MEPS for Group 5S are being sought.

Group 6C: Products in this Group are evenly split above and below the compact size, but in fact the m ajority of sal es lie in the com pact size range (thi s group m akes up about half of al l separate freezer sal es). While there are a few products that exceed the non com pact MEPS level, these are hi ghly specialised custom or hi gh end European products that are not acti vely sold in Australia. It is noted that the Com pact MEPS level for Group 6C l ies closer to the 2010 M EPS level than the 2015 non compact level (about 60 kW h/year higher than the non com pact MEPS level). It is acknowledged that the non compact 2015 MEPS level for this Group is very stringent for all product sizes and w ill necessitate 80mm+ of polyurethane w ith very high efficiency compressors.

Group 6U: The vast majority of products in this Group fall into the compact category. There are quite a few products that just exceed the non compact MEPS level (some by a si gnificant margin), all in the sm aller size range. It i s noted that the Com pact MEPS level for Group 6U l ies somewhat closer to the 2010 MEPS level (about 50 to 60 kWh/year higher than the non compact MEPS level).

Group 7: The majority of products in this Group are larger than the compact category. There are some products that just exceed the non compact MEPS level for all sizes. It is noted that the Compact MEPS level for Group 7 i s relatively weak (cl ose to the 2010 MEPS line; about 140 kWh/year higher than the non compact 2015 MEPS level).



Annex G – Background information on wine storage and beverage coolers

G.1 US MEPS Proposals

When the US devel oped new M EPS levels for ref rigerators and f reezers to be implemented in 2001, DOE l imited the appl ication of i ts refrigerator standards to exclude wine chillers and sim ilar products on the basis that the test procedure w as unable to deal with these types of products.

The forthcoming US regul atory definition of an el ectric refrigerator is a product: “. . . designed to be capable of achieving storage temperatures above 32°F (0°C) and below 39°F (3.9°C), . . .” (CFR430.2). This effectively excludes most wine storage cabinets and som e other types of refrigeration products from the current MEPS regime.

The US al so has other types of produc t exclusions under the Energy Pol icy and Conservation Act (EPCA) of 1975, which include:

• products designed solely for use i n recreational vehicles and other m obile equipment

• any type designed to be used without doors

• any type whi ch does not i nclude a com pressor and condenser uni t as an integral part of the cabinet assembly.

Many of these differences are set out in Paper 2 in Appendix C.

The US are proposing to modify coverage of the Act to include wine storage and other miscellaneous refrigeration products that use the vapour compression cycle as part of a separate rule making (as set out i n detail in Paper 2). They are al so considering a separate rule for AC-powered thermoelectric and absorption refrigeration products (76 FR 69147, Nov. 8, 2011) – at this stage these products are still under consideration with respect to MEPS.

DOE is considering adopting the following definition for electric wine chiller:

• [A] cabinet designed for the refri gerated storage of bever ages, non-perishable food products, and/or any other i tems, is not desi gned to be capabl e of achieving storage tem peratures below 39°F (3.9°C), and havi ng a source of refrigeration requiring single phase, alternating current electric energy input.

They expect that the defi nition for refri gerator would be m odified to i nclude both electric refrigerator and electric wine chiller. The U S notes that m ost wine chillers fall into the compact size category (less than 219 litres), so they are i ntending to have a separate category for w ine chillers that in cludes all sizes ranges (does not have a separate compact size category). The U S is still debating how to deal w ith hybrid products (standard compartments combined with a wine storage compartment), with



the main issue under consi deration the proportion (share) of vol ume for each compartment type for a hybrid product to be considered either a refrigerator or a wine chiller.

The US propose to have a Noti ce of Proposed Rulemaking for a test procedure for wine chillers and m iscellaneous refrigeration by about S eptember 2012 w ith a final rule in about May 2013.

The US have already released the Framework Document for the energy conservati on standard (MEPS) for these products in February 2012, together with a public meeting on 22 February 2012. Li nks to these docum ents are i ncluded in the references. A Notice of Proposed R ulemaking for M EPS for w ine chillers and m iscellaneous refrigeration is expected by about October 2013 wi th a final rule in about m id 2014, with implementation by 2017.

While the MEPS levels are nowhere near f inalised, the US is considering the MEPS levels that have al ready been i mplemented in California and Canada as a starti ng point. These are:

Manual defrost wine chillers: 267 + 0.48 AV

Automatic defrost wine chillers: 344 + 0.61 AV

The ambient temperature during this test is 32.2°C. Thi s could create som e minor longer term practical issues if the US c ontinue to use an am bient of 32.2°C as I EC propose an energy test condi tion of 32° C and 16°C for dedi cated wine storage cabinets and performance tests are conducted at 25°C.

G.2 Approach to Cover These Products under AS/NZS

G.2.1 Compartment definitions

Under the IE C test m ethod the follow ing additions and clarific ations will be m ade regarding compartment definitions.

Firstly, the IEC test m ethod defines several applicable compartment types in the test method Part 3 Cl ause 4.1 Tabl e 1. Thes e are wi ne storage, vegetable, cellar and pantry compartments. Wine storage and cel lar have a target tem perature for energy consumption of 12°C. Pantry has a target tem perature for energy consum ption of 17°C. A vegetable compartment has a target temperature for energy of 10°C.

The following qualifications and clarifications for these compartment types have been proposed to IEC (but are l ikely to be i ncluded as part of the determination if not accepted by IEC):

• Wine storage compartments are compartments that are used exclusively for the maturation of wi ne and onl y have storage space for wi ne bottles (noting that IEC rates the vol ume of wine storage compartment in terms of the num ber of 750ml bottles);

• Vegetable compartments are used to storage vegetabl es and frui t at temperatures warmer than fresh food i n higher humidity conditions to sl ow dehydration;



• Cellar compartments are used for the storage of dr inks and non peri shable items and will include any warmer compartments not classified as wine storage or vegetable compartment types – these are al so referred to as be verage storage compartments;

• Any compartment that i s unable to operate bel ow an average com partment temperature of 12°C for energy testi ng shall be cl assified as a Pantry compartment for energy testing purposes.

It is important to note that under the IE C test method being adopted in Australia and NZ, the follow ing mandatory requirements will apply (as set out in IE C Clause 4.1 Table 1):

Where a compartment has a separate temperature control than can operate over a

temperature range that spans the target temperature of more than one compartment

type (in IEC Tabl e 1), it shall be classified and operated as the compartment type

which has the highest energy consumption for the energy test. If a compartment

operating range spans none of the target temperatures for the defined compartment

types in Table 1 (because it has no control or a limited range of active control), then it

shall be classified as the compartment type with the next warmest target temperature

and operated at its warmest setting (where adjustable) for the energy test.

Generally, the compartment type with the highest energy will be the coldest possible function. The onl y exception to thi s general rule is where a warm er temperature is attained through the use of a heater. Thi s rule means that i f a co mpartment control allows it to operate continuously at a temperature of less than +4°C during the energy test conditions at both am bient temperatures, then it must be classified as fresh food for energy testing purposes

5.

Compartments that have space for any items other than 750ml litre wine bottles will be classified as a cel lar compartment (or another appl icable compartment type, depending on the temperature of operation).

G.2.2 New group definitions

Under AS/NZS4474.2 two new Group definitions will be included to cover dedicated wine storage cabi nets and m iscellaneous refrigeration products (i ncluding beverage coolers).

Dedicated wine storage cabinets will cover products that use the vapour com pression cycle for cool ing, are designed to operate at 12°C or warmer, are exclusively for the storage and m aturation of wi ne (one or m ore wine storage com partments with no other compartment types) and m eet the general design requirements set out i n AS/NZS4474.1-2007 1.3.18(e) as follows:

i. the capability of m aintaining continuously a nom inated storage temperature across a range of norm al operating ambient temperatures, by m eans of heating or cooling as applicable;

5 Stakeholder comment is sought on whether this ru le should apply to dedicate wine storage

compartments as well.



ii. the capability of m aintaining temperatures within a variation over tim e of less than 0.5 K;

iii. control of the compartment humidity; and

iv. construction to reduce the transm ission of vi bration to the com partment, whether from the refrigerator compressor or from an external source.

A new Group 8 w ill include products that have one or m ore dedicated w ine storage compartments and no other com partment type. Dedicated wine storage cabinets w ill be split into automatic defrost and manual defrost types. Those where al l compartments have automatic defrost will be classified as G roup 8A. The where one or more compartments are manual defrost will be classified as Group 8M.

A new Group 9 called Miscellaneous Refrigeration will include products that have one or more cellar or pantry com partments (for beverage st orage) and no other compartment type. It w ill also include other products where the coldest com partment is warmer than fresh food (but excl uding Group 8 products). W here a cel lar compartment is combined with one or m ore compartments that operate at 4°C or colder, then the product shall be classified into one of the existing Groups 1 to 7 and it shall be treated as a hybrid product (see below).

The revised standard would also include the existing definitions of product designation (refrigerator, refrigerator-freezer, freezer, cooled appliance) (see AS/NZS4474.1-2007 Clause 1.3.18). As set out i n the E3 Product Regulatory Proposal, a new category of wine storage cabi net should be added to designation. Under the Regulatory

Discussion Document, products that have a designation of cooled appliances will have to carry a warning label in lieu of a star rating label.

G.2.3 Apply IEC test method for energy determination and performance

Unlike the US test m ethod, there is no problem applying the IEC test m ethod for the determination of energy fo r wine storage and beverage cool ing products (cellar compartments). Wine storage com partments and beverage cool ing (cellar) compartments will have an energy target tem perature of 12°C (irrespective of the actual temperature of operation) or will be classified as a panty (17°C) if the product is unable to operate at bel ow 12°C on the co ldest setting for energy testi ng at both ambient temperatures. A com partment that can operate at 4° C or l ess cannot be classified as a cellar compartment.

Dedicated wine storage cabinets w ill be required to m eet the performance requirements in the IEC test m ethod (Part 1 Annex H and Part 2 Annex B). Miscellaneous beverage coolers (including cellar com partments) will be required to meet the normal performance tests in the IEC standard (including the storage test and the pull down test).

G.2.4 Application of MEPS for Miscellaneous Refrigeration Products (Group 9)

Group 9 products w ill have MEPS applied for the first tim e in 2015. The M EPS level applied will be equivalent to those set for Group 3 products in the A ustralia in 1999. These products w ill then have their M EPS levels upgraded in 2018 to levels



equivalent to the US 2017 MEPS levels for these products. These products will not be permitted to carry a star rati ng energy label – they will carry a warning label instead where they have a designation of cooled appliance.

MEPS levels for Group 9 products in 2015 will be as set out in Equation 1 with:

Kf = 330 kWh/year Kv = 0.800 kWh/year/adjusted litre

Details are set out in the Regulatory Discussion Document.

G.2.5 Application of MEPS for Dedicated Wine Storage Cabinets (Group 8)

Group 8 products w ill have MEPS applied for the first tim e in 2015. The M EPS level applied will be equivalent to those set for Group 3 products in the A ustralia in 1999. These products w ill then have their M EPS levels upgraded in 2018 to levels equivalent to the US 2017 MEPS levels for these products. These products will not be permitted to carry a star ra ting energy label – they will carry a warning label instead where they have a desi gnation of cooled appliance. Effectively wine storage cabinets (Group 8) w ill be subjected to the sa me requirements as m iscellaneous beverage coolers (Group 9) until 2018, where the US MEPS levels w ill be adopted and these may different for these two groups.

G.2.6 Application of MEPS for Hybrid Products

AS/NZS4474.1 and AS/N ZS4474.2 mandate MEPS, energy labelling and performance requirements for al l hybrid products that com bine any wi ne storage compartment with any standard com partment type. From 2015, this w ill also apply to any beverage storage (cel lar or pantry) co mpartment that i s combined with any standard compartment type (that operates at 4°C or colder).

From 2015 al l products m ust meet the re levant requirements for perform ance and MEPS for the applicable AS/NZS Group (applies to all Groups and all designations).

Products that have a des ignation of refrigerator, refrigerator-freezer or freezer w ill be required to carry a star rati ng label (applies to al l Groups). Products that have a designation of cooled applian ce or w ine storage cabinet w ill be required to carry a warning label (applies to all Groups). Details are set out i n the Regulatory Discussion

Document.



Annex H – Summary of Adjustments for MEPS 2005

H.1 Introduction

This annex illustrates the adjustm ents that were made in 2000 when adapting the US 2001 MEPS levels for implementation in Australia in 2005. This is provided for general information only at the request of DCCEE. While the differences appear to be significant for som e Groups, these need to be interpreted i n the context of the differences in the test method that existed between the US and Austral ia at that time. An explanation of the source of the di fferences is set out bri efly in the fol lowing sections for each group. M ore detailed information can be obtai ned from the fi nal working group document published in 2000 at the conclusion of the process to set the 2005 MEPS levels (EES, 2000).

It is important to note that the work on adapt ing the US 2001 M EPS levels for Australia was done i n the period from 1999 to 2000 and the l evel of knowledge and understanding at the time was much less than is available today. So the conversions, while generally reasonable, we based on t he best avai lable data and approaches at the time. The approach to developing new MEPS levels for Australia and NZ in 2015 (based in US 2014 levels) is drawing on this previous approach in general terms, but the level of data and inform ation is greatly improved and so the process w ill be more accurate. The new IEC test m ethod is much more flexible, which allows many of the outstanding differences between US and Aust ralia/NZ to be concisely quantified. And many of the test m ethod components for t he US and the IEC are now very cl osely aligned, which reduces the m agnitude of any adjustments that may be required. The adjustments taken into account from US 2014 M EPS to AS/NZS 2015 MEPS are set out in the Regulatory Discussion Document and in B.9 of this document.

Table 7: Comparison of MEPS levels for US MEPS 2001 and Australia/NZ MEPS 2005

AS/NZS

Group

US

Category

US

Fixed US Variable

US

FAF

AU/NZ

Fixed

AU/NZ

Variable

AU/NZ

FAF

Rep size

L

US

MEPS

AU

MEPS AU Diff

1 3A 276 0.346082 1 278 0.335 1 325 388.4 386.8 -0.4%

2 1A 248.4 0.311473 1.44 289 0.29 1.2 111 284.3 321.8 13.2%

3 1 248.4 0.311473 1.44 283 0.344 1.4 118 287.3 325.8 13.4%

4 2 248.4 0.311473 1.63 277 0.33 1.6 219 324.9 357.6 10.1%

5T 3 276 0.346082 1.63 311 0.357 1.6 367 424.9 463.5 9.1%

5B 5 459 0.162446 1.63 411 0.357 1.6 476 551.8 613.3 11.1%

5S 4 507.5 0.173394 1.63 569 0.169 1.6 612 639.5 696.5 8.9%

6U 8 303.9 0.313675 1.73 281 0.298 1.6 129 373.7 342.3 -8.4%

6C 10 205.3 0.498438 1.73 190 0.483 1.6 227 401.3 365.6 -8.9%

7 9 383.6 0.516422 1.73 356 0.478 1.6 311 661.9 594.2 -10.2%

Note: Values in red have US field use factors removed.



H.2 Overall Test Method Differences and Considerations

When comparing the US M EPS levels and t hose set for Australia, it is important to take into account the fact that there a num ber of diffe rences that w ill impact on the measured energy consumption. Some of these are listed below:

• The US energy tests are conducted at 32.2°C (cf 32.0°C under AS/NZS).

• Internal compartment temperatures were different for al l equivalent Groups (these are discussed in the commentary for each Group).

• The US use an average of al l freezer temperature sensors (cf warmest 4 under AS/NZS) and the positions of sensor are slightly different.

• Different freezer adjustment factors by Group.

• There are some significant differences in the volume measurement procedure under each test method.

• There are significant differences in the permitted defrost interval under AS/NZS.

It is important to note that compact products existed under t he US 2001 M EPS definitions, but these were very restri ctive in that the vol ume was less than 219 litres and the height was less than 36” (0.91m). No equivalent compact product definition appeared in the AU 2005 MEPS levels.

There were also a significant number of other considerations taken into account when adapting the US 2001 MEPS levels for Australia in 2005. These are set out in the final working group consensus paper prepared by EES (2000). The main issues were:

• Test voltage and transition to 230V

• Availability of high efficiency compressors for R134a and 230V/50Hz

• Humidity performance

• Impact of the use of 50Hz vs 60Hz fans

• GWP of foam blowing agents (US us ed HFC141b whi le local products were using cyclopentane with lower GWP and slightly higher conductivity)

• Performance tests (temperature operation test and pull down test)

• Small differences in defrost peri od definition (in addition to the assum ed interval).

A significant issue was the use of Long Ti me Automatic Defrost i n the US, whi ch effectively gave many frost free products wi th electronic controls a defrost i nterval of 40 to 80 hours (defaul t value of 48 hours). Under the AS/NZS te st procedure, the maximum permitted defrost was 24 hours for all models, irrespective of the measured defrost interval. To accommodate this, products that had the potential to adjust defrost interval in accordance wi th defrost need we re given the so cal led “adaptive defrost” allowance under MEPS (in effect 5% additional energy). Because the components of defrost and steady state were not separately quantified in the test m ethods at the time, the allowance was developed by empirical means and analysis of selected data.



Many of the US categori es included a through the door i ce dispenser. For Australian MEPS, the effective energy allowance for each of these groups was reviewed and an average flat figure for al l groups was a pplied (this is an i dentical approach that has been proposed during the adaptation of US 2014 MEPS).

On point of deviation in Australian MEPS in 2005 was t he inclusion of an “additional door” allowance. This was i ncluded on the basi s that a product wi th more compartments will use m ore energy in t he energy test (heat gain through additional gaskets) but i t may use less energy during normal use from reduced ai r exchanges during door openi ng where these were spr ead across a l arger number of sm all compartments. This impact was never really quantified at the time.

The following sections provide a brief overview of the differences by AS/NZS Group.

H.2 Group 1

Under the US test m ethod, this group has the sam e internal-external temperature difference, so the energy differences are very small (US 32.2°C to 3.3°C vs AU 32.0°C to 3.0°C). None of the other adjustments are appl icable so the MEPS levels are almost the same.

H.3 Groups 2, 3 and 4

Under the US test m ethod, these groups have a m uch warmer permitted fresh food temperature (7.22°C vs 3. 0°C). Some additional adjustments were requi red due to differences in internal target temperatures.

H.4 Groups 5T, 5B and 5S

Under the US test method, these groups have a m uch warmer permitted fresh food temperature (7.22°C vs 3.0°C). The US 2001 M EPS level for Group 5B was considered to be unreflective of the physical factors that drive energy for that group (US MEPS had a very high fixed value with almost a flat volume based component – this may have been workable in the US where there was a narrow range of sizes available, but in Australia there were many diffe rent sizes available). So the Australian 2005 M EPS levels for Group 5B were based on Group 5T + 100 kW h/year. Interestingly, the US 2014 M EPS levels has adopted a line that has a similar slope to that adopted in Australia and NZ in 2005.

H.5 Groups 6C, 6U and 7

There are two large drivers for differences in energy for these Groups between the US and Australia/NZ. The first is that Groups 6U and 7 under the US test method have an overall “field use factor” of 0.85 appl ied to the m easured energy. For chest freezers (Group 6C) this factor is 0.7. These factors have been adjusted out of the values listed in Table 7 (values in red). The second big difference is that under the US test method, separate freezers had a target temperature of 0°F ( -17.8°C) while AS/NZS target temperature was -15. 0°C. This means the AS/NZS MEPS levels have t o be considerably tighter to take i nto account the warmer freezer temperatures under the AS/NZS test method.



H.6 Adjustments for AS/NZS MEPS Levels from 2005 to 2010

The Consultation Regulatory Impact Statement of proposed revisions to the method of test and energy labelling al gorithms for household refr igerators and freezers (EES 2008) set out the technical basis for adjusting the MEPS level for 2 main factors:

• Conversion of the MEPS levels from a m odel average energy requi rement to that which specifies a m aximum permitted energy for any i ndividual unit (technically equivalent levels for an assumed production variability);

• Small adjustments to the MEPS levels due t o changes i n the approach t o measuring compartment temperatures in AS/NZS4474.1-2007, which now includes the period of defrost and recovery (this is the same as in the new IEC test method, but remains a point of difference with the US) (appl icable to frost free Groups only).

The US cont inues define MEPS as t he maximum energy perm itted for a m odel average production. This is considered problematic in terms of veri fication and enforcement, so conversion to a m aximum permitted energy will continue to be used in Australia and NZ. The sam e approach used for 2010 has been adopted to covert US 2014 MEPS to AS/NZS 2015 MEPS.



Annex I – Check list of issues to be covered by Part 2

As a consequence of adoption of the new IEC test method in place of AS/NZS4474.1, there are a number of practical issues that need to be checked and covered i n Part 2 to ensure the continued smooth operation of MEPS and energy labelling.

The most significant issue is moving the definition of Groups i nto Part 2. There are a number of consequential changes associated with this action. It i s important to note that IEC do not define anything like Groups – this is regarded as a matter for national or regional authorities (as categori es or Groups are onl y applied when regul ating products for energy, so these necessarily have to be regionally relevant).

The other critical thing w ill be to m ove definition of product desi gnation into P art 2. Product designation w ill be im portant as th is will determine the energy labelling requirements for the product as set out in the Regulatory Discussion Document.

The other i ssue to be consi dered is to moving some of the defi nitions used for regulatory purposes i nto Part 2 i f these ar e not al ready covered by IEC defi nitions. The recommended approach w ill be list all definit ions currently in P art 1 and check whether these are a) i ncluded in the IEC and i f not b) w hether they are requi red for energy labelling or MEPS in Australia and NZ.

Other issues that may need to be considered for a new Part 2 include:

• Any requirements that m ay need to be included in a determ ination (the m ain items have already been noted in Annex A)

• Declaration and veri fication requirements (some are in P art 2, m ost will be in separate government guidelines), noting that some performance requirements may need addi tional guidance regarding the perform ing verification tests and interpretation of verification results.

• Rules regarding model number declarations where these are broadl y based on measured volumes (the current AS/NZS ru le regarding model numbers is not included in the IE C and som e measured volumes will be reduced under the new IEC m ethod, making many current model numbers non com pliant if the rule is retained in Part 2).

• Ensuring that al l configurations are covered i n the absence of speci al compartments (which are not defined in IEC, but there are rules on how to deal with intermediate compartments and variable temperature compartments).

Specific items to be checked are:

• Current net effect of the scope of AS/NZS4474.1 and AS/NZS4474.2 and how the scope of the new IEC may affect the overall requirements and requirements in Part 2.

• Rules regarding convenience features (IEC rules are similar)

• Consequences for the deletion of special compartments



• Rules for M ulti-use compartments versus Vari able compartments (equivalent IEC term, slight differences in application)

• Performance requirements to be defined in Part 2, where applicable.

• Elimination of shelf area test

• Elimination of Clause 3.7.3 temperature performance requirements for energy.

• Elimination of specific marking requirements

• Rules regarding measured volume and decl aration of m odel number designations where these are similar (AS/NZS4474.1 Clause 4.4)

• Test voltage and frequency to be fixed at 230V and 50Hz for all tests

• Move Appendix P regarding group interpretation to Part 2

• Test report summary requirements in Part 2

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