Opportunities for Success and CO 2 Savings from Appliance Energy Efficiency Harmonisation:

Transcription

1 Opportunities for Success and CO 2 Savings from Appliance Energy Efficiency Harmonisation: Part 2: An Assessment of Test Procedures and Efficiency Metrics PUBLISHED MARCH 2011 By Paul Waide, Navigant Consulting in Partnership with CLASP, the Collaborative Labeling & Appliance Standards Program

2 This report has been produced for the Collaborative Labeling and Appliance Standards Program (CLASP) Prepared by 2010 Paul Waide, PhD Navigant Consulting 5 th Floor, Woolgate Exchange 25 Basinghall Street London, EC2V 5HA Tel: Fax: Paul.Waide@NavigantConsulting.com and Lloyd Harrington, Energy Efficiency Strategies, Australia with support from: Michael Scholand, Aris Karcanais, Rowan Watson Mark Ellis Navigant Consulting (Europe) Ltd. All rights reserved April This document is expressly provided to and solely for the use of the Collaborative Labeling and Appliance Standards Program (CLASP). Navigant Consulting (Europe) Ltd accepts no liability of whatsoever nature for any use of this document by any other party. Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 2

3 CONTENTS Executive Summary Introduction Room air conditioners (non ducted air conditioners)... 3 Overview of the product... 3 Comparison of energy performance test procedures... 3 Comparison of energy efficiency metrics... 8 Recommended directions Central air conditioners (ducted air conditioners) Overview of the product Comparison of energy performance test procedures Comparison of energy efficiency metrics Recommended directions Chillers for commercial buildings Overview of the product Comparison of energy performance test procedures Comparison of energy efficiency metrics Recommended directions Household refrigeration appliances Overview of the product Comparison of energy performance test procedures Comparison of energy efficiency metrics Recommended directions Household clothes washing machines Overview of the product Comparison of energy performance test procedures Comparison of energy efficiency metrics Recommended directions Household clothes dryers Overview of the product Comparison of energy performance test procedures Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 3

4 Comparison of energy efficiency metrics Recommended directions Household dishwashers Overview of the product Comparison of energy performance test procedures Comparison of energy efficiency metrics Recommended directions Water heating appliances Overview of the product Comparison of energy performance test procedures Comparison of energy efficiency metrics Recommended directions Televisions Overview of the product Comparison of energy performance test procedures Comparison of energy efficiency metrics Recommended directions Digital television decoders (set top boxes) Overview of the product Comparison of energy performance test procedures Comparison of energy efficiency metrics Recommended directions External power supplies Overview of the product Comparison of energy performance test procedures Comparison of energy efficiency metrics Recommended directions Lighting GLS and CFli Recommended directions Lighting Ballasts Recommended directions Lighting Halogen and reflector lamps Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 4

5 Recommended directions Lighting Linear Fluorescent Lamps and related systems Recommended directions Lighting HID lamps Recommended directions Lighting LEDs Recommended directions Space heating devices Comparison between US & EU Test Procedures/Systems for Efficiency Recommended directions Fans and ventilators Recommended directions Office equipment, ICT and standby power Office equipment ICT Standby power Recommended directions Electric motors Recommended directions Cooking appliances Recommended directions Transformers Recommended directions Commercial refrigeration equipment Recommended directions Conclusions Appendix A: Summaries of current standards and labelling requirements and test procedures Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 5

6 ACRONYMS AND ABBREVIATIONS ANOPR Advance Notice of Proposed Rulemaking ANSI American National Standards Institute AP Acidification Potential ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers Btu British Thermal Unit CCT Correlated Colour Temperature CDM Clean Development Mechanism CECED European Home Appliance Manufacturers Association CEN European Committee for Standardisation CENELEC European Committee for Electrotechnical Standardization CFL Compact Fluorescent Lamp CFLi Compact Fluorescent Lamp with integrated ballast CFLn Compact Fluorescent Lamp without integrated ballast CFR Code of Federal Regulations CHP Combined Heat and Power CMH Ceramic Metal Halide CIE International Commission on Lighting CNCA Certification and Accreditation Commission of China CNIS China National Institute of Standardization CRI Colour Rendering Index CSCC China Standards Certification Centre (formerly the China Certification Centre for Energy Conservation Products, CECP) CW Constant Wattage isolated transformer (HID magnetic ballast) CWA Constant Wattage Autotransformer (HID magnetic ballast) DALI Digital Addressable Lighting Interface DG-TREN Directorate General for Energy and Transport DG-ENTI Directorate General for Enterprise and Industry DG-Environment Directorate General for Environment DOE Department of Energy (United States of America) EACI Executive Agency on Competitiveness and Innovation EC European Commission EEAP Energy Efficiency Action Plan EERE Office of Energy Efficiency and Renewable Energy (DOE) EIA Energy Information Administration (DOE) EISA Energy Independence and Security Act (2007) ELC European Lamp Companies Federation EMAS Eco-Management and Audit Scheme EN European Standard (Européenne Norme) EPA Environmental Protection Agency Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 6

7 EPACT Energy Policy Act (1992 and 2005) EPCA Energy Policy and Conservation Act (1975) ETAP Environmental Technologies Action Plan EU European Union EU SDS European Union s Sustainable Development Strategy EuP Energy-Using Products FCC Federal Communications Commission (US) FR Federal Register FTC Federal Trade Commission GDP Gross Domestic Product GEF Global Environment Facility GHG Green House Gases GLS General Lighting Service GPP Green Public Procurement GWP Global Warming Potential HEP High Efficiency Plasma HID High Intensity Discharge HP Horsepower (US motors equivalent to kw) HPS High Pressure Sodium HX High Reactance Autotransformer (HID magnetic ballast) ICT Information and Communication Technology IEC International Electrotechnical Committee INPV Industry Net Present Value IP Intellectual Property IPP Integrated Product Policy IPPC BREFs Integrated Pollution Prevention and Control, Best Available Techniques IS Indian Standard ISO International Organization for Standardization JIS Japan Industrial Standard JRA Japan Refrigeration and Air Conditioning Industry Association kw Kilowatt (EU motors equivalent to HP) LCC Life Cycle Cost LED Light Emitting Diode LLD Lamp Lumen Depreciation LLF Light Loss Factor LPS Low Pressure Sodium LPW Lumens Per Watt PBP Payback Period MEEUP Methodology study for Ecodesign of Energy-Using Products MFD Multi-Function Devices (e.g., all-in-one: printer, copier, scanner, phone.) MH Metal Halide MIA Manufacturer Impact Analysis Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 7

8 MV NOPR NPV OLED PMH SAC SEPA SCP/SIP SI STB TSD UL US USC WEEE Mercury Vapour Notice of Proposed Rulemaking Net Present Value Organic Light Emitting Diode Pulse-start Metal Halide Standardization Administration of China State Environmental Protection Administration (China) Sustainable Consumption and Production / Sustainable Industrial Policy le Système International d'unités Set Top Box Technical Support Document Underwriters Laboratory United States United States Code (i.e., Congressional Statute) Waste Electrical and Electronic Equipment (EU Directive) Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 8

9 EXECUTIVE SUMMARY Energy performance test procedures and energy efficiency metrics underpin all the equipment regulations in place internationally such as MEPS, Top Runner regulations, and all forms of energy labelling. There are varying degrees of international harmonisation for these test procedures depending on the product type and economy in question. This report reviews the test procedures and energy efficiency metrics in use within the five major economies of China, the EU, India, Japan and the USA for the following twenty four energy using equipment types: 1. Room air conditioners (non ducted air conditioners) 2. Central air conditioners (ducted air conditioners) 3. Chillers for commercial buildings 4. Household refrigeration appliances 5. Household clothes washing machines 6. Household clothes dryers 7. Household dishwashers 8. Water heating appliances 9. Televisions 10. Digital television decoders (set top boxes) 11. External power supplies 12. Lighting GLS and CFli 13. Lighting Ballasts 14. Lighting Halogen and reflector lamps 15. Lighting Linear Fluorescent Lamps and related systems 16. Lighting HID lamps 17. Lighting LEDs 18. Space heating devices 19. Fans and ventilators 20. Office equipment, ICT and standby power 21. Electric motors 22. Cooking appliances 23. Transformers 24. Commercial refrigeration equipment It assesses the degree of commonality and divergence in the test procedures and efficiency metrics and considers the prospects both from a technical and process driven perspective for enhanced international alignment and harmonisation for each of these products. It also presents comparative tables that summarise the main characteristics of the test procedures and efficiency metrics in place for each economy as they relate to existing energy efficiency regulations, and allows a cross comparison on a product by product basis between the economies. Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 9

10 Table 1 presents a summary of the status of and prospects for harmonisation for each of the products considered. Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 10

11 Table 1 Summary of test procedure harmonisation prospects Product/end-use Degree of harmonisation for energy test procedures Regions with greatest difference from international standards Potential for harmonisation of energy test procedures Comments Room air conditioners (Ducted) Central air conditioners (Non-ducted) High Japan, USA Fair Treatment of split units in USA and variable capacity units everywhere are the main sources of difference. Japan and EU are moving to part-load testing approach High/Moderate USA Fair New ISO standard under consideration; US would need to re-categorise split AC systems Chillers High/Moderate Good No international test procedure; however, work on an ISO standard has been approved Household refrigeration appliances Moderate/Poor India, Japan, USA Moderate/Poor New IEC standard expected in 2011 should help improve prospects Household clothes washers Low Japan, USA Moderate/Poor New IEC standard will address all clothes washer types (horizontal and vertical) but local wash temperatures and cleaning requirements vary dramatically Household clothes dryers Low All Moderate/Poor IEC61121 is under revision and should encourage greater harmonisation Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 11

12 Household dishwashers Moderate USA Fair New IEC standard could be made more attractive if prescriptive requirements were optional Product/end-use Degree of harmonisation for energy test procedures Regions with greatest difference from international standards Potential for harmonisation of energy test procedures Comments Water heating appliances Low All Moderate New IEC standard under development could form the basis of a global standard Televisions Moderate EU is first to adopt Fair IEC62087 Edition was specifically developed as a global energy measurement standard and should be adopted Digital television decoders (set top boxes) Moderate Good IEC62087 Edition was specifically developed as a global energy measurement standard and should be adopted External power supplies High Very good The draft international test method is broadly based on the approach used by Energy Star International; delay in issuance presents risk Lighting: GLS and GLS High Japan, USA Fair Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 12

13 lookalikes Lighting: CFLi High Good New IEC standard likely to have broad support Lighting: fluorescent ballasts High/Moderate Japan, USA Moderate No technical justification for differences in test standards Lighting: directional lamps Too soon to say Good Greenfield product: opportunity for new international standards to gain broad acceptance Lighting: linear fluorescent lamps High/Moderate Japan, USA Moderate No technical justification for differences in test standards Product/end-use Degree of harmonisation for energy test procedures Regions with greatest difference from international standards Potential for harmonisation of energy test procedures Comments Lighting: HID lamps High/Moderate Japan, USA Moderate No technical justification for differences in test standards Lighting: LEDs Too soon to say None Good Greenfield product: opportunity for new international standards to gain broad acceptance Space heating devices Low All Poor except air to air heat pumps Too much regional product diversity except for air-to-air heat pumps Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 13

14 Fans and ventilation High/Moderate USA Good IEC standards are adequate and widely used Office Equipment, ICT, Standby power High None Good International Energy Star is the most common testing platform; broad support for IEC standby power standard Electric motors High None Very good New IEC standard likely to have broad support Cooking appliances Low All Moderate/Poor Cooking appliances are poor candidates for international harmonisation except microwaves and maybe ovens Transformers High None Good Little variation in test procedures implies good potential for harmonisation Comm. refrigeration equipment Moderate Uncertain Some confusion at present, but the field is relatively open Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 14

15 1. INTRODUCTION The purpose of this report is to provide information that will support CLASP and its partners to assess the degree to which greater international harmonisation and alignment within the various major energy efficiency standards and labelling programmes could help bring about significant energy and CO2 savings. Efficiency standards and labelling schemes are currently in place for a variety of end-use equipment types in countries that account for about 80% of the world s population and a higher share of its GDP, energy use and CO2 emissions. While these programmes are mostly highly cost effective and have saved significant amounts of energy and CO2, there are also many limitations and lost opportunities as follows: The share of energy using products subject to energy efficiency policy requirements varies significantly such that there is no economy where all end-uses are subject to requirements, while in most there are very significant gaps 1. The stringency of these requirements varies significantly The apparent effectiveness of product labelling varies significantly Compliance with requirements is often poorly assessed and weakly enforced The test procedures and metrics to define energy use and energy efficiency respectively are sometimes inadequate or nonexistent (in the worse case) and often vary among economies making performance comparison difficult 2 The degree to which complementary policies to stimulate energy savings in products operated within energy using systems are applied varies even more greatly and may have even larger savings potential. This study, commissioned by CLASP, and conducted by Navigant Consulting (Europe) with support from Energy Efficiency Strategies (Australia) presents a review and analysis of the current situation focused on the five major global economies of China, the European Union, India, Japan and the USA. 1 As of today China and the USA/Canada have the most mandatory product energy efficiency specifications. Europe is rapidly catching up through its Eco-design programme and Japan has relatively extensive, but slightly less, product coverage via its Top Runner programme. India is somewhat behind and currently has no mandatory product efficiency requirements. 2 The EU almost exclusively applies test procedures that are aligned with international (ISO/IEC) test procedures. China also mostly uses international test procedures (ISO/IEC/IEEE/ITU) but in some cases uses those from other leading economies (USA, Japan, Canada) and has also developed some purely national test procedures. India uses many ISO/IEC test procedures but often with local adaptation and in one or two cases has aligned with other test procedures (such as the Australian/New Zealand procedure for refrigerators). North American test procedures are mostly aligned between the USA and Canada (and often Mexico) but these are usually not aligned with ISO/IEC test procedures. Sometimes international test procedures are used and in many cases common elements exist between US and international test procedures. Japan has a mix of fully ISO/IEC harmonised and national test procedures, which nonetheless often have some degree of alignment with ISO/IEC. The rest of the world uses predominantly ISO/IEC test procedures with some locally specific variations. The main exceptions are Australia/New Zealand who apply a mixture of regional and fully internationally aligned test procedures. Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 1

16 It presents a thorough review of existing energy efficiency standards and labelling programmes (S&L programmes) with the exception of requirements that apply to transportation or non-energy using equipment. The section of the study reported in this document (Part 2) reviews the existing energy efficiency test procedures and energy efficiency metrics in place. It describes and compares the existing test procedures in use, considers their similarities and differences and analyses the prospects for greater harmonisation amongst them. This is done for each of the 24 energy end-uses in turn. Appendix A provides a complete listing of energy efficiency standards and labelling schemes applied in the five major economies excepting those applying to transportation end-uses, non-energy enduses and industrial processes. It constitutes a useful resource summarising key details of the existing regulations in a comparable manner. Part 1 of this study, written into a separate document: reviews and compares the S&L certification, accreditation & compliance procedures applied in the different economies provides a synthesis of issues concerned with the harmonisation/alignment process and documentation and analysis of factors to consider that influence its feasibility delivers a review and summary of the institutions and processes involved in setting test procedures, test regimes, regulations and compliance structures provides a determination and ranking of the viability of alignment/harmonisation by product type and an estimation of energy, CO2 and cost savings potentials from harmonisation or alignment of the most promising product types Part 3 of this study, written into a separate document, presents descriptions of the leading equipment energy efficiency requirements in place for each economy. Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 2

17 2. ROOM AIR CONDITIONERS (NON DUCTED AIR CONDITIONERS) Overview of the product Room air conditioners are a mainstream product in developed economies and many developing economies are experiencing rapid increases in ownership. A range of technologies can be used for air conditioners. This section concentrates on systems that use the vapour compression cycle and air to air heat exchangers for cooling and/or heating of an indoor space. The systems covered have no air interchange between the outdoors and the conditioned space and they discharge conditioned air directly into the conditioned space (non-ducted configuration). The main configurations are split systems (single or multi) and unitary systems (mainly window wall, but also some small packaged systems). Typically, these have a limited capacity (usually up to around 15kW cooling output) and are usually designed to condition a limited space within a residential dwelling or office. Room air conditioners are a global commodity and there is widespread international trade. There are generally only small differences in product design at a regional level. North America treats split systems as central units, which means they have to be tested in a different fashion, but the product is otherwise the same as elsewhere. North America also has a product type called a packaged terminal air conditioner which appears to be limited to the USA this is effectively a unitary non-ducted system. There are differences in terminology in some parts of the world, particularly in North America. There is no international standard which defines air conditioner types and configurations 3. Comparison of energy performance test procedures Key parameters to consider for efficiency testing and measurement A room air conditioner is essentially a heat pump that that collects energy from one space and moves it to another space using the vapour compression cycle. The main components are a compressor, refrigerant in a distribution system (including an expansion valve), an evaporator and a condenser. The direction of heat flow depends on the mode of operation: while cooling, the heat is collected from the inside space and moved outside. In heating mode, heat is collected from outside and moved to the inside space. The amount of heat that can be moved is generally considerably greater than the energy used to drive the refrigeration system, hence the apparent efficiency is typically in the range 200% to 500% (defined as output over input). For products that can operate in heating and cooling mode, the heating efficiency generally appears more efficient as the energy used to drive the compressor can also contribute to the overall output. The key parameters used for efficiency testing and measurement are the input energy (electricity) and output (total heating or cooling capacity). These two parameters can be used to define overall efficiency of the product during operation. 3 Note: the technologies not included in this section are evaporative coolers, water sourced heat pumps, chillers (that provide cooled water), systems that use cooling towers and ducted systems. Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 3

18 As set out in great detail in expert and academic literature, the efficiency of a refrigeration system (like the one used in an air conditioner) is affected by the indoor/outdoor temperatures and temperature difference (or more correctly the operating temperature of the evaporator and condenser) and the overall operating efficiency of the refrigeration system under that condition (which is a function of the compressor parameters and the heat transfer rate and surface area of the evaporator and condenser). Some energy is used by components such as fans and to some extent electronics and in some cases auxiliary heaters (e.g. for defrosting). In order to obtain accurate comparative efficiency value of the air conditioner system itself, the indoor and outdoor conditions need to be carefully controlled. Accurate determination of the output of an air conditioner also requires careful measurement (volume and temperature of air, plus dehumidification effect in the case of cooling) this parameter can be subject to large errors when some approaches are used. The most accurate approach to testing for efficiency is a calorimeter where there is an overall check on the energy balance of the indoor and outdoor sides of the system. Calorimeters also give the best result for non ducted product where conditioned air is delivered directly to the room. The air enthalpy method can be used to measure the capacity and efficiency of non-ducted products, but there can be problems in accurately measuring the energy discharge into the conditioned space as it is difficult to replicate the natural mixing and recirculation of the product under normal use conditions. The air enthalpy method does not provide an overall check of energy balance during testing. The other key parameter which affects the overall energy consumption of room air conditioners is the non-operational energy consumption. Most test procedures do not currently deal with this parameter. Overview of the international test method The international test method for room air conditioners: ISO Non-ducted air conditioners and heat pumps -- Testing and rating for performance. This standard is used very widely around the world. The standard defines the following parameters for testing purposes: Definitions Determination of capacity and energy efficiency; A range of performance tests in cooling and heating mode; Uncertainties and tolerances. For the determination of capacity, 3 possible combinations of indoor and outdoor conditions are defined. Condition T1 is used almost universally for cooling capacity determination and efficiency claims. T2 (mild conditions) and T3 (very hot conditions) are rarely specified. Condition high for heating is most commonly used, although low is sometimes specified for colder climates. Condition extra-low is not used widely for rating (climates with sub-zero temperatures tend to opt for other technologies like ground source heat pumps). Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 4

19 Table 1: Cooling and heating conditions in ISO5151 Cooling conditions T1 T2 T3 Indoor 27 C DB, 19 C WB 21 C DB, 15 C WB 29 C DB, 19 C WB Outdoor 35 C DB, 24 C WB 27 C DB, 19 C WB 46 C DB, 24 C WB Heating conditions High Low Extra Low Indoor 20 C DB, <15 C WB 20 C DB, <15 C WB 20 C DB, <15 C WB Outdoor 7 C DB, 6 C WB 2 C DB, 1 C WB -7 C DB, -8 C WB Notes: DB = dry bulb, WB = wet bulb Importantly, ISO5151 defines a range of performance tests that check whether the air conditioner is fit for purpose. For cooling these include maximum cooling, minimum cooling, enclosure sweat and condensate disposal tests and a freeze up test. For heating these include maximum heating, minimum heating and an automatic defrost test. Some of these tests are mandated within some testing regimes. Not all tests are relevant for all users. In terms of efficiency the standard defines Energy Efficiency Ratio (EER) as the ratio of cooling output (W) to electrical input (W) this variable is dimensionless (W/W). It also defines the Coefficient of Performance (COP) for heating in a similar fashion. ISO5151 specifies both calorimeter and air enthalpy test setups for energy and capacity determination. ISO5151 does not address non operating power. Adequacy of the international test method There are two main limitations to ISO5151 as it is currently written regarding operating efficiency. The first limitation is that most regulatory regimes specify condition T1 for cooling performance and condition high for heating performance. While this provides good comparative data of overall system efficiency at the defined operating conditions, this may not necessarily represent the actual efficiency achieved during normal use. For many products, the relative efficiency will not change much with operating condition, which is why this limitation has largely been ignored until recently. The second limitation is a more significant problem (but of a similar nature) that has come about due to recent changes in the technology used in air conditioners. Over the past 10 years, the share of inverter driven products (or more correctly, compressor with variable output) has increased dramatically to a point where the these are used almost universally in Japan and are dominant in Australia and other regions (for example). For a standard single speed compressor (which used to predominate), the refrigeration system always runs at full load when operating. The overall output of the system is modulated by changing the compressor on time and off time (50% output for example would be achieved by operating the compressor approximately half of the time). Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 5

20 A variable output system operates on different basis. In order to achieve a reduced capacity, the speed or output of the compressor is reduced to match the load required. This means that the units run continuously across a wide range of required outputs. The key advantage of these systems is that they avoid compressor start-up losses and generally they can operate at increased efficiency at part load conditions. This increased efficiency occurs because at part load the refrigerant flow from compressor is reduced but the surface area of the evaporator and condenser remains the same, resulting in an overall improvement of heat transfer. Thus the operating efficiency during normal use is likely to be better than the value obtained at rated capacity (full load). However, there can be some so called parasitic losses to run the variable output system, so the efficiency gains vary by model and by output. To some extent these two limitations are related in that the standardized test conditions (T1 and High ) when measured at rated capacity do not necessarily reflect the operating efficiency at other conditions and outputs for some types. When the market was dominated by single speed compressors, the differences in operating efficiency at conditions that were different to T1 were relatively small and part load efficiency of single speed compressors changes little at reduced capacity (if anything this should deteriorate slightly), so the problems were ignored. However, with a large share of variable output product on the market, the test procedure as written does not provide a good representation of part load or seasonal variation in efficiency. Unless this is addressed, divergence from the test procedure that has to date been widely used globally may begin to occur. The other issue which is not covered by ISO5151 is the measurement of non-operating energy of room air conditioners. Most room air conditioners now use some power when the refrigeration system is not operating. This power can be used for a range of functions such as remote controls, timers and even remote communications (including load control). Some room air conditioners also have heating systems (commonly called crank case heaters) which are used to stop refrigerant condensing and pooling in the compressor chamber (liquid in the compressor can damage it during starting). Crank case heaters are uncommon for room air conditioners (although they can be present) but are more common on larger ducted systems. Typical power consumption for crank case heaters is 30W to 100W, but some systems can use as much as 200W. Over a year this can account for a large amount of energy. The measurement of non operating power is usually straight forward when only functions related to communications and controls are involved (as these usually remain constant under different ambient conditions). The control and operation of crank case heaters can be complex in some cases these range from simple heaters that are on when the system is not operating to more complex systems that are controlled by ambient temperature and/or by operating schedules (e.g. heaters may not operated for a specified period after the operation has stopped due to residual heat in the system). Regional differences in products and testing approaches There are surprising few significant variations in testing approaches to room air conditioners globally. There are some minor variations in web bulb requirements in some Asian countries and some small differences due to conversion from Celsius to Fahrenheit temperature scales, but these are minor variations. There are also some differences in the expression of efficiency (EER) in the some regions, where outputs are expressed in British Thermal Units (BTU) or kilo-calories, but the underlying concept of output over input is used fairly universally. The most significant variation to the fundamental test requirements is in North America where split systems have to be tested to the requirements for central air conditioners, which requires the determination of a Seasonal Energy Efficiency Ratio (SEER). This requires test data at 4 different test conditions which are then combined to reflect an overall annual efficiency for a specified average Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 6

21 North American climate. One of the test points is equivalent condition T1. The other points have the same indoor conditions with reduced (milder) outdoor conditions. Table 2: North American SEER test conditions for room air conditioners Condition Indoor Outdoor Condition A (equivalent to ISO T1) 27 C DB, 19 C WB 35 C DB, 24 C WB Condition B 27 C DB, 19 C WB 28 C DB, NS - WB Condition C 27 C DB, 14 C WB 28 C DB, NS WB Condition D 27 C DB, 14 C WB 28 C DB, NS WB Testing to conditions C and D are optional in that if the tests are not done, a value of 0.25 is assigned for the degradation co-efficient CD. Only four tests are required for single speed compressors. Where there is a two speed compressor, tests at condition A and B are to be done for each speed. For variable speed compressors, up to seven tests are required as follows: A and B wet coil tests at maximum compressor speed B wet coil is tested at minimum speed Low temperature wet coil test is conducted at minimum speed (indoor and outdoor 19.4/13.9oC dry/wet) Final wet coil test is conducted at an intermediate speed if a value for CD of 0.25 is not used, dry coil tests C and D at minimum speed. Comparability of regional testing approaches As most regions globally have used the standard ISO5151 T1 and High test conditions to rate and compare their products, there is generally very good alignment and comparability of test data for air conditioners. The exception is North American due to the SEER requirement for split systems. However, data for the T1 test condition should be available for all products, which would allow direct comparison of products. Subjective assessment of the level of international harmonisation for testing There is a high degree of international harmonisation regarding the use of ISO5151, with the exception of North American requirements for split systems. The historical domination of single speed compressor units has meant that the imperfections in ISO5151 are relatively minor under many usage conditions and could be ignored. However, the growing dominance of variable output units now means that there is a lot of pressure to provide better information on the relative efficiency of these units under a range of operating conditions. Unless this issue is addressed in the near future, there may be moves to diverge from ISO5151 by the addition of more test conditions. Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 7

22 Prospects and key directions for international harmonisation of testing There is already good international harmonisation for room air conditioners through ISO5151. However, the test procedure needs to be made more relevant for variable output products, which can change their efficiency with changes in output and operating conditions. Work is under way in ISO to develop a basis for a seasonal rating system for air conditioners. The approach is to define a series of standard test conditions. The standard test points can then be used to estimate, via a series of equations, operating efficiency under different operating conditions and different output levels, which can be used to estimate performance under different climates. The intent is to provide a standard comparative annual performance rating for international comparative purposes, but more importantly, to provide a standard methodology to calculate the annual performance of a product under a wide range of possible climate and usage conditions using data from a limited number of standard test points. The methodology under development, if accepted, will provide a sound basis for providing more accurate performance data for a large number of climates and usage levels without the need for extensive testing and it will also address current concerns regarding the relative efficiency of variable output air conditioners. For this approach to be successful, the data for each of the standard test points needs to be separately reported. Comparison of energy efficiency metrics Common Efficiency Metrics and Regional Approaches The most widely used efficiency metric for room air conditioners is the EER for cooling and COP for heating that is derived from ISO5151. This measure is essentially output power over input power and provides a direct measure of operating efficiency. When stated with the cooling output and the heating output, EER and COP provides all of the data required for efficiency comparisons. In terms of energy labelling, there are a wide different systems for depicting the categorical efficiency of air conditioners within individual country rating systems. Categories are depicted by various symbols such as numbers, letters and stars. However, all of these rating systems use EER and COP as the underlying efficiency measure to determine the category rating. In some regions (e.g. North America) the raw EER number is quoted as the efficiency metric (noting that that this is in BTU/W rather than W/W). Similarly, EER and COP are generally used to define minimum energy performance standards (MEPS) where applicable. The exception is North America that uses SEER for split systems. SEER is specifically determined for a specified North American climate, which makes this parameter of little value to most other regions in the world (and many parts of North America). The values for each of the test points are generally not reported as separate parameters. Some countries now include non-operating power consumption in their overall efficiency requirements. This is an important measure to ensure that manufacturers minimize this as far as possible. Performance Issues The approach to performance requirements varies by country. In North America, single speed compressor split systems are subject to four performance tests: high temperature test, Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 8

23 cyclic test, frost accumulation test low temperature test. Variable speed units are subject to: high temperature test (one maximum speed, two at minimum speed), cyclic test (minimum speed), frost accumulation test (maximum and intermediate speeds). Other countries specify one or more of the performance tests in ISO5151 as a prerequisite to their energy labelling or MEPS programs. It is usually advisable to mandate certain minimum performance tests to ensure that the products are fit for purpose and will actually work under the range of expected operated conditions normally encountered. Comparability of efficiency metrics At this stage, there is very good comparability of efficiency data across different regions where this is reported at ISO5151 condition T1 for cooling and High for heating. North American data for split systems tends to report SEER only, which cannot be directly compared to results at T1. However, efficiency at T1 is one of the standard test points that makes up the SEER value so separate reporting of this value in addition to SEER would make data highly comparable across regions. Recommended directions There is already a good level of global harmonisation in the testing and reporting of room air conditioner energy efficiency. The main exception is in North America where SEER is used for split systems. SEER is not directly comparable to ISO T1 conditions. However, ISO T1 data makes up one of the test conditions used to calculate SEER, so if this value could also be separately reported, this would allow direct regional comparability. There is growing international pressure to take into account the improved performance of variable output compressors under both part load output and milder operating conditioners. Unless this issue is adequately addressed in the near future, there is likely to be a divergence of testing approaches around the globe. ISO are working on a globally applicable approach to determine a seasonal performance for air conditioners which is based on measured performance at a set of specified rating conditions which can be used to estimate efficiency under a range of operating conditions and outputs. Most importantly, a methodology is being developed to allow seasonal performance to be calculated for any selected climate zone. Once accepted, this should address many of the current concerns. It is important that a global test procedure for air conditioners define the conditions of measurement for non operating power in an accurate and relevant manner. This can then be used by different regions as required within efficiency programs without the need to generate local requirements to address this issue. The seasonal calculation approach also needs to address non operating power as this can be a significant element of total energy consumption. This work by ISO should be supported on the understanding that it will be based on a limited number of standard testing points and the methodology will allow these test point results to be converted into a seasonal rating for any selected climate. It is also critical that the methodology to calculate seasonal ratings be publicly available. The resulting standard should also mandate the separate reporting of all data for all of the standard test conditions which are specified to allow different regions to apply relevant weightings to reflect their local conditions. Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 9

24 3. CENTRAL AIR CONDITIONERS (DUCTED AIR CONDITIONERS) Overview of the product Central air conditioners are a mainstream product in developed economies. This section concentrates on systems that use the vapour compression cycle and air to air heat exchangers for cooling and/or heating of an indoor space. It also covers some larger packaged systems use small cooling towers to improve their cooling efficiency and capacity (where the cooling tower is used as a heat sink). This section does not cover water sourced or ground sourced heat pumps. The systems covered have no air interchange between the outdoors and the conditioned space and they discharge conditioned into a duct system that coveys conditioned air to one or more conditioned spaces (ducted configuration). The main configurations are generally unitary systems (packaged systems) and split systems. Ducted systems can range from 5kW to as much as 70kW. They are usually designed to condition a large area within commercial buildings, although they are also used for some larger residential systems in developed countries. Many of the larger systems run multiple compressors in one or multiple refrigeration systems. Central air conditioners are a global commodity and there is widespread international trade. There are generally only small differences in product design at a regional level. North America has different test procedures for these types of units, but the product is otherwise the same as elsewhere. There are differences in terminology in some parts of the world, particularly in North America. There is no international standard which defines air conditioner types and configurations. Notes: The technologies not included in this section are evaporative coolers, water or ground sourced heat pumps (covered by ISO13256), chillers (that provide cooled water see next section), non ducted systems (see previous section). Comparison of energy performance test procedures Key parameters to consider for efficiency testing and measurement A central air conditioner is essentially a heat pump that that collects energy from one space and moves it to another space using the vapour compression cycle. The main components are a compressor, refrigerant in a distribution system (including an expansion valve), an evaporator and a condenser. The direction of heat flow depends on the mode of operation: while cooling, the heat is collected from the inside space and moved outside. In heating mode, heat is collected from outside and moved to the inside space. The amount of heat that can be moved is generally considerably greater than the energy used to drive the refrigeration system, hence the apparent efficiency is typically in the range 200% to 500% (defined as output over input). For products that can operate in heating and cooling mode, the heating efficiency generally appears more efficient as the energy used to drive the compressor can also contribute to the overall output. The key parameters used for efficiency testing and measurement are the input energy (electricity) and output (total heating or cooling capacity). These two parameters can be used to define overall efficiency of the product during operation. As discussed in the section on non-ducted air conditioners, the efficiency of a refrigeration system (like the one used in an air conditioner) is affected by indoor/outdoor temperatures and the temperature difference. Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 10

25 In order to obtain accurate comparative efficiency value of the air conditioner system itself, the indoor and outdoor conditions need to be carefully controlled. Accurate determination of the output of an air conditioner also requires careful measurement (volume and temperature of air, plus dehumidification effect in the case of cooling) this parameter can be subject to large errors when some approaches are used. The air enthalpy method is generally considered to be acceptable for ducted systems as accurate measurement of air flow and temperature in the output duct is relatively straight forward (in comparison to non-duct systems which discharge directly to the conditioned space). However, a calorimeter is still preferable as the air enthalpy method does not provide an overall check of energy balance during testing. However, calorimeters have a natural capacity limit and generally it is difficult to test systems larger than 12kW to 15kW in a calorimeter, so larger ducted systems cannot be tested using this approach. The other key parameter which can affect the overall energy consumption of room air conditioners is the non-operational energy consumption. Most test procedures do not currently deal with this parameter. Overview of the international test method The international test method for central air conditioners ISO Ducted air conditioners and heat pumps -- Testing and rating for performance. This standard is used very widely around the world. The standard defines the following parameters for testing purposes: Definitions Determination of capacity and energy efficiency; A range of performance tests in cooling and heating mode; Uncertainties and tolerances. The structure and detail of the standard is very similar to ISO5151 for non-ducted systems (refer to the previous section for details). Some local regulatory approaches do not divide products purely on the basis of ducted and non-ducted, so there can be some mismatch between the international test methods and local requirements in some cases. In terms of efficiency the standard defines Energy Efficiency Ratio (EER) as the ratio of cooling output (W) to electrical input (W) this variable is dimensionless (W/W). It also defines the Coefficient of Performance (COP) for heating in a similar fashion. ISO13253 specifies air enthalpy test setups for energy and capacity determination. ISO13253 does not deal with non operating power. Adequacy of the international test method The limitations to ISO13253 are the same as ISO5151 see discussion in the previous section on nonducted (room) air conditioners. Regional differences in products and testing approaches Most regions require the use of ISO13253 Condition T1 for energy efficiency and capacity testing. The most significant variation to this test requirement is in North America where central air conditioners (as well as non-ducted split systems) require the determination of a Seasonal Energy Efficiency Ratio Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 11

26 (SEER). This requires test data at 4 (or more) different test conditions which are then combined to reflect an overall annual efficiency for a specified average North American climate. One of the test points is equivalent condition T1. The other points have the same indoor conditions with reduced (milder) outdoor conditions. Table 3: North American SEER test conditions for central air conditioners Condition Indoor Outdoor Condition A (equivalent to ISO T1) 27 C DB, 19 C WB 35 C DB, 24 C WB Condition B 27 C DB, 19 C WB 28 C DB, NS WB Condition C 27 C DB, 14 C WB 28 C DB, NS WB Condition D 27 C DB, 14 C WB 28 C DB, NS WB Testing to conditions C and D are optional in that if the tests are not done, a value of 0.25 is assigned for the degradation co-efficient CD. Only four tests are required for single speed compressors. Where there is a two speed compressor, tests at condition A and B are to be done for each speed. For variable speed compressors, up to seven tests are required as follows: A and B wet coil tests at maximum compressor speed B wet coil is tested at minimum speed Low temperature wet coil test is conducted at minimum speed (indoor and outdoor 19.4/13.9oC dry/wet) Final wet coil test is conducted at an intermediate speed if a value for CD of 0.25 is not used, dry coil tests C and D at minimum speed. Comparability of regional testing approaches As most regions globally have used the standard ISO13253 T1 and High test conditions to rate and compare their products, there is generally very good alignment and comparability of test data for air conditioners. The exception is North American which uses SEER for all central air conditioners. However, data for the T1 test condition should be available for all products, which would allow direct comparison of products. Subjective assessment of the level of international harmonisation for testing There is a high degree of international harmonisation regarding the use of ISO13253, with the exception of North American requirements. The historical domination of single speed compressor units has meant that the imperfections in ISO13253 are relatively minor under many usage conditions and could be ignored. However, the growing dominance of variable output units now means that there is a lot of pressure to provide better information on the relative efficiency of these units under a range of operating conditions. Unless this issue is addressed in the near future, there may be moves to diverge from ISO13253 by the addition of more test conditions to better reflect part load performance. Success and CO2 Savings from Appliance Energy Efficiency Harmonisation Page 12