Tier

Tier 1 a/b

It is expected that the refrigeration and air conditioning will be a key category for many countries. The implication of this conclusion from Table 7.2 and the decision tree in Figure 7.6 is that either country-specific or globally or regionally derived activity data will be required at the sub-application (disaggregated) level in order to complete the reporting task. However, in the rare instances that the refrigeration and air conditioning application is much less significant, there should be available a suitable Tier 1 method for aggregated data.

From experience of studying the dynamics of refrigerant consumption and banks in several countries (UNEP-RTOC, 2003; Ashford, Clodic, Kuijpers and McCulloch, 2004; and supporting materials), it is possible to derive assumptions that allow for the assessment of the use of refrigerant that may help in assessing sales of a given refrigerant at a country level. Such a hybrid Tier 1a/b approach may use the following assumptions:

1. Servicing of equipment containing the refrigerant does not commence until 3 years after the equipment is installed.

2. Emissions from banked refrigerants average 15 percent annually across the whole RAC application area. This assumption is estimated to be a weighed average across all sub-applications, for which default emission factors are shown in Table 7.9.

3. In a mature market two thirds of the sales of a refrigerant are used for servicing and one third is used to charge new equipment. A mature market is one in which ODS substitute-employing refrigeration equipment is in wide use, and there are relationships between suppliers and users to purchase and service equipment.

4. The average equipment lifetime is 15 years. This assumption is also estimated to be a weighed average across all sub-applications.

5. The complete transition to a new refrigerant technology will take place over a 10 year period. From experiences to date, this assumption is believed to be valid for a single chemical in a single country.

With these assumptions in place, it is possible to derive emissions, if the following data can be provided:

• Sales of a specific refrigerant in the year to be reported

• Year of introduction of the refrigerant

• Growth rate in sales of new equipment (usually assumed linear across the period of assessment)

• Assumed percentage of new equipment exported

• Assumed percentage of new equipment imported

The Tier 1a/b method then back-calculates the development of banks of a refrigerant from the current reporting year to the year of its introduction. In mapping this period, the method also models the transition from sales to new equipment (100 percent initially) to the mature market position assumed based on experience to be 33 percent to new equipment and 67 percent to servicing requirements. It is assumed that the transition to new refrigerant technology is reflected identically in any imported equipment.

Figure 7.6 Decision tree for actual emissions from the refrigeration and air conditioning

(RAC) application

Figure 7.6 Decision tree for actual emissions from the refrigeration and air conditioning

(RAC) application

Note:

1. See Volume 1 Chapter 4, Methodological Choice and Identification of Key Categories (noting Section 4.1.2 on limited resources), for discussion of key categories and use of decision trees.

Note:

1. See Volume 1 Chapter 4, Methodological Choice and Identification of Key Categories (noting Section 4.1.2 on limited resources), for discussion of key categories and use of decision trees.

The following spreadsheet example indicates how the Tier 1a/b method would estimate a seven-year time series of emissions of the selected refrigerant, following its initial introduction in 1998, with the knowledge that there were sales of 1 000 tonnes in 2005. The spreadsheet contained in the 2006 Guidelines CDROM mirrors this calculation, and globally or regionally derived datasets21 at both application and consolidated sub-application levels should be available at a country level to assist in completion of this spreadsheet.

21 As noted in Box 7.1, inclusion in the IPCC Emission Factor Database (EFDB) will indicate general adherence to due process, but it is good practice for countries to ensure that all data taken from the EFDB are appropriate for their national circumstances.

Figure 7.7

Example of spreadsheet calculation for Tier 1a/b assessments

Tier 1 Refrigeration Argentina - HFC-143a

Figure 7.7

Tier 1 Refrigeration Argentina - HFC-143a

\Current Year

\Current Year

Summary

Country: Argentina Agent: HFC-143a Year: 2005

Emission: 460.7 tonnes

In Bank: 3071.1 tonnes

Data Used Here

Use in current year - 2005 (tonnes)

Production of HFC-143a Imports in current Year Exports in current year

800

200

0

Total new agent to domestic market

1000

Year of Introduction of HFC-143a Growth Rate in New Equipment Sales

1998

3.0%

Tier 1 Defaults

Assumed Equipment Lifetime (years) Emission Factor from installed base % of HFC-143a destroyed at End-of-Life

15

15%

0%

In Bank: 3071.1 tonnes

Estimated data for earlier years

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

Production

0

0

81

167

259

355

458

566

680

800

Agent in Exports

0

0

0

0

0

0

0

0

0

0

Agent in Imports

0

0

20

42

65

89

114

141

170

200

Total New Agent in Domestic Equipment

0

0

102

209

323

444

572

707

850

1000

Agent in Retired Equipment

0

0

0

0

0

0

0

0

0

0

Destruction of agent in retired equipment

0

0

0

0

0

0

0

0

0

0

Release of agent from retired equipment

0

0

0

0

0

0

0

0

0

0

Bank

0

0

102

296

575

933

1365

1867

2437

3071

Emission

0

0

15

44

86

140

205

280

365

461

In this hypothetical example, the production of a specific refrigerant are 800 tonnes with an additional 200 tonnes in imported equipment, in 2005 making a total consumption of 1 000 tonnes. Based on this consumption figure and knowledge of the year of introduction of the refrigerant, it can be seen that the Tier 1a/b method predicts emissions of 461 tonnes based on the development of banks over the previous seven years. The bank in 2005 is estimated at 3 071 tonnes.

It should be noted that, while such methods allow for the estimation of emissions when data are difficult to obtain, it is still necessary to have an accurate assessment of country-specific or globally or regionally derived net consumption activity data. When the content of Table 7.8 is considered (particularly when some of these blends may be being imported in equipment) it is clear that there needs to be considerable knowledge of technology selection in the market. Refrigerant suppliers should be able to assist inventory compilers in this area, but the burden of developing high quality activity datasets may lead inventory compilers to the conclusion that Tier 2 options provide more value with little extra work. Indeed, where globally or regionally validated data activity is sought, this will normally be a reconstitution of disaggregated data originally at the sub-application level, so it might be most logical to take full advantage of that versatility and pursue a Tier 2 approach from the outset.

TIER 2 Overview

The Tier 2a methodology:

a) Takes into account the phase out or the phase down of CFCs and HCFCs depending on the Montreal Protocol schedule and possible national or regional regulations, in order to establish the refrigerant choice for all applications;

b) Defines the typical refrigerant charge and the equipment lifetime per sub-application;

c) Defines the emission factors for refrigerant charge, during operation, at servicing and at end-of-life.

Calculation of emissions throughout the equipment lifetime requires deriving the total stock of equipment independent of their vintage. In doing so the refrigerant bank is established per sub-application.

In order to achieve consistency it is suggested to derive the annual market of refrigerants from the refrigerant quantities charged in the brand new equipment and from the refrigerant quantities used for servicing of the total stock of equipment.

The Tier 2b mass-balance approach relies on a knowledge of the annual sales of refrigerant, refrigerant destroyed and any changes in equipment stock that occur (i.e., new equipment sales and equipment decommissioned) on a sub-application basis. It does not require an absolute knowledge of equipment stocks or emission factors relating to each refrigeration and air conditioning sub-application.

Examples of how the Tier 2 methodology may be applied are given in the remainder of this section. Tier 2b - Mass-balance approach

The mass-balance approach is particularly applicable to the Refrigeration and Air Conditioning application because of the significant servicing component required to maintain equipment. The general approach to Tier 2b is introduced in Chapter 1 of Volume 3.

For the mass-balance approach, the four emission stages (charging, operation servicing and end-of-life) identified above are addressed in the following simplified equation:

Equation 7.9

Determination of refrigerant emissions by mass balance

Emissions = Annual Sales of New Refrigerant - Total Charge of New Equipment

+ Original Total Charge of Retiring Equipment - Amount of Intentional Destruction

Annual Sales of New Refrigerant is the amount of a chemical introduced into the refrigeration sector in a particular country in a given year. It includes all chemical used to fill or refill equipment, whether the chemical is charged into equipment at the factory, charged into equipment after installation, or used to recharge equipment at servicing. It does not include recycled or reclaimed chemical.

Total Charge of New Equipment is the sum of the full charges of all the new equipment that is sold in the country in a given year. It includes both the chemical required to fill equipment in the factory and the chemical required to fill the equipment after installation. It does not include charging emissions or chemical used to recharge equipment at servicing.

Original Total Charge of Retiring Equipment is the sum of the full charges of all the retiring equipment decommissioned in a country in a given year. It assumes that the equipment will have been serviced right up to its decommissioning and will therefore contain its original charge.

Amount of Intentional Destruction is that quantity of the chemical duly destroyed by a recognised destruction technology.

In each country there is a stock of existing refrigeration equipment that contains an existing stock of refrigerant chemical (bank). Therefore, annual sales of new chemical refrigerant must be used for one of three purposes:

• To increase the size of the existing chemical stock (bank) in use (including retrofitting equipment from a previous chemical to the given chemical)

• To replace that fraction of last year's stock of chemical that was emitted to the atmosphere (through, for example, leaks or servicing losses)

• To provide supply-chain priming or stockpiles

Since the third item in this list is rarely required in a steady-state market, it is not included in Equation 7.9. Terms to account for stockpiling and retrofitting could be added to Equation 7.9 if such situations exist.

The difference between the total quantity of gas sold and the quantity of that gas used to increase the size of the chemical stock equals the amount of chemical emitted to the atmosphere. The increase in the size of the chemical stock is equal to the difference between the total charges of the new and retiring equipment.

By using data on current and historical sales of gas, rather than emission factors referenced from literature, the equation reflects assembly, operation, and disposal emissions at the time and place where they occur. Default emission factors may not be accurate because emissions rates may vary considerably from country to country and even within a single country.

As discussed in Chapter 1, Section 1.5 of Volume 3, one drawback of the mass-balance approach is that it can underestimate emissions when equipment stocks are growing, because there is a lag between the time the emissions occur and the time they are detected (through equipment servicing). This underestimate will be relatively large in countries where HFCs have been used in equipment for less than ten years, because much of the equipment will have leaked without ever being serviced. Thus, countries where HFCs have been used for less than ten years are encouraged to estimate emissions using alternative approaches. In general, the longer HFCs are used in a country, the smaller the underestimate associated with the mass-balance approach. Once equipment containing HFCs begins to retire, the underestimate declines to a low level.

Equation 7.9 can be applied either to individual types of equipment (sub-applications), or more generally to all air conditioning and refrigeration equipment in a country (i.e., Tier 1b), depending on the level of disaggregation of available data. If disaggregated data are available, emissions estimates developed for each type of equipment and chemical are summed to determine total emissions for the application.

Tier 2a - Emission-factor approach

In a Tier 2a calculation, refrigerant emissions at a year t from each of the six22 sub-applications of refrigeration and air conditioning systems are calculated separately. These emissions result from:

• Econtainers,t = emissions related to the management of refrigerant containers

• Echarge,t = emissions related to the refrigerant charge: connection and disconnection of the refrigerant container and the new equipment to be charged

• Elifetime,t = annual emissions from the banks of refrigerants associated with the six sub-applications during operation (fugitive emissions and ruptures) and servicing

• Eend- of-life,t = emissions at system disposal

All these quantities are expressed in kilograms and have to be calculated for each type of HFC used in the six different sub-applications.

Equation 7.10 Summary of sources of emissions

Etotal ,t = Econtainers ,t + ECharge,t + Elifetime,t + Eend-of-life,t

Methods for estimating average emission rates for the above-mentioned sectors are outlined below and need to be calculated on a refrigerant by refrigerant basis for all equipment regardless of their vintage. If information on container and charging emissions is not available, inventory compilers can estimate these losses as a percent of the bank and revise the lifetime (operation plus servicing) emission factor in Equation 7.13 below to account for such losses.

Refrigerant management of containers

The emissions related to the refrigerant container management comprises all the emissions related to the refrigerant transfers from bulk containers (typically 40 tonnes) down to small capacities where the mass varies from 0.5 kg (disposable cans) to 1 tonne (containers) and also from the remaining quantities - the so-called refrigerant heels (vapour and /or liquid) - left in the various containers, which are recovered or emitted.

Where:

Econtainers, t = emissions from all HFC containers in year t, kg

RMt = HFC market for new equipment and servicing of all refrigeration application in year t, kg c = emission factor of HFC container management of the current refrigerant market, percent

The emissions related to the complete refrigerant management of containers are estimated between 2 and 10 percent of the refrigerant market.

Refrigerant charge emissions of new equipment

The emissions of refrigerant due to the charging process of new equipment are related to the process of connecting and disconnecting the refrigerant container to and from the equipment when it is initially charged.

22 More than six sub-applications can be used, depending on the level of disaggregated data available.

Where:

Echarge, t = emissions during system manufacture/assembly in year t, kg

Mt = amount of HFC charged into new equipment in year t (per sub-application), kg k = emission factor of assembly losses of the HFC charged into new equipment (per sub-application), percent

Note: the emissions related to the process of connecting and disconnecting during servicing are covered in Equation 7.13.

The amount charged (Mt) should include all systems which are charged in the country, including those which are produced for export. Systems that are imported pre-charged should not be considered.

Typical range for the emission factor k varies from 0.1 to 3 percent. The emissions during the charging process are very different for factory assembled systems where the emissions are low (see Table 7.9) than for field-erected systems where emissions can be up to 2 percent.

Emissions during lifetime (operation and servicing)

Annual leakage from the refrigerant banks represent fugitive emissions, i.e., leaks from fittings, joints, shaft seals, etc. but also ruptures of pipes or heat exchangers leading to partial or full release of refrigerant to the atmosphere. Besides component failures, such as compressor burn-out, equipment is serviced mainly when the refrigerating capacity is too low due to loss of refrigerant from fugitive emissions. Depending on the application, servicing will be done for instance every year or every three years, or sometimes not at all during the entire lifetime such as in domestic refrigeration sub-applications. For some sub-applications, leaks have to be fixed during servicing and refrigerant recovery may be necessary, so the recovery efficiency has to be taken into account when estimating emission factors. In addition, knowing the annual refrigerant needs for servicing per sub-application allows the determination of the national refrigerant market by adding the refrigerant quantities charged in new equipment (see Paragraph Quality assurance/Quality control). The following calculation formula applies:

Where:

Ei!fetime, t = amount of HFC emitted during system operation in year t, kg

Bt = amount of HFC banked in existing systems in year t (per sub-application), kg x = annual emission rate (i.e., emission factor) of HFC of each sub-application bank during operation, accounting for average annual leakage and average annual emissions during servicing, percent

In calculating the refrigerant bank (Bt) all systems in operation in the country (produced domestically and imported) have to be considered on a sub-application by sub-application basis.

Examples of typical leakage rates (x) for various types of equipment describing the respective refrigeration subapplications are given in Table 7.9.

Emissions at end-of-life

The amount of refrigerant released from scrapped systems depends on the amount of refrigerant left at the time of disposal, and the portion recovered. From a technical point of view, the major part of the remaining fluid can be recovered, but recovery at end-of-life depends on regulations, financial incentives, and environmental consciousness.

The following calculation formula (Equation 7.14) is applicable to estimate emissions at system disposal:

Where:

Eend-of-iife, t = amount of HFC emitted at system disposal in year t, kg

Mt-d = amount of HFC initially charged into new systems installed in year (t-d), kg p = residual charge of HFC in equipment being disposed of expressed in percentage of full charge, percent nrec,d = recovery efficiency at disposal, which is the ratio of recovered HFC referred to the HFC contained in the system, percent

In estimating the amount of refrigerant initially charged into the systems (M t-d), all systems charged in the country (for the domestic market) and systems imported pre-charged should be taken into account.

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