Estimating numbers of appliances in use, unit sales, emissions and future development (World Map)

To estimate present emissions and their future development, a comprehensive modelling approach was applied. The first step was to model the stock, i.e., the number of appliances in use in the various countries. Future unit sales and emissions were derived from the modelled stock.

Our modelling approaches

The stock for the various RAC subsectors was calculated by two different methods, depending on the available data. The list of covered systems is not exhaustive.

Where it was possible, a sophisticated modelling approach was chosen to estimate the stock, where a relationship is built between the current response (stock, diffusion rate, ownership) and the current predictor variables. The following predictors were considered: Population, GDP, temperature index, urbanisation and electrification rates. Specifically, generalised linear models and generalised additive models were used to model the stock accordingly. Penetration rates for domestic refrigerators were taken from McNeil & Letschert (2008).

This detailed approach requires very specific information, and it is thus limited to RAC systems with a sound database to calibrate the models.

A simpler modelling approach to calculate the stock is based on ratios of RAC systems per inhabitants. These ratios were primarily built based on data given in Schwarz et al. (2011) who provide numbers of RAC equipment for developing and developed countries. Using this approach, the only factors that determine the stock are population and number of households. This approach is limited in its informative value because it does not reflect purchasing power or climatic conditions. However, it gives a first estimate about the number of systems in use. The table below shows which approach was applied to the different systems.

RAC SubsectorSophisticated approachSimple ratio approach
Unitary air conditioningSplit residential ACSelf-contained AC Commercial ducted splits Multi-splits
Chillers Air conditioning chillers
Mobile air conditioningMAC in passenger carsLarge vehicle AC (buses only)
Domestic refrigerationDomestic refrigeration 
Commercial refrigeration Stand-alone equipment Condensing units Centralised systems
Industrial refrigeration Centralised systems
Transport refrigeration 

Refrigerated trucks/trailers

Heat pumpsCovers only EU-28 and is based on sales data and analysis provided in the European Heat Pumps Market and Statistics Report (EHPA, 2023)


The modelled stock was used to derive unit sales figures, taking into account that a certain part of the equipment is decommissioned at end-of-life. Multiplying the unit sales figures by current unit market prices results in market value estimates.

In this top-down approach, countries are divided into three country groups (CG). Country Group 1 (CG1) includes all non-Article 5 countries under the Montreal Protocol except the EU, Country Group 2 (CG2) comprises all Article 5 countries and Country Group 3 (CG3) consists of all countries in the European Union including the United Kingdom (EU-28). Although each country has individual stocks, the assumptions and parameters used in the sophisticated and simple ratio approaches are shared within the countries of a CG. The stock and sales figures were then used to calculate current and future CO2 emissions, accounting for direct (refrigerants) and indirect (energy consumption) emissions. To calculate direct emissions, the average initial charge per appliance type and emission factors at 3 stages in the life cycle of equipment were considered. In addition, the following parameters were used:

  1. leakage during manufacturing
  2. annual leakage rates during the lifetime
  3. remaining and vented refrigerant at the end of life.

These factors are calculated as a percentage of the initial charge. These parameters are estimated for each type of equipment in the different RAC sectors and for each CG. Indirect emissions are calculated by estimating the energy consumption of each equipment type and then multiplying it by the grid emission factor of each country. In the case of equipment that is powered by electricity generated from fuel, such as mobile air conditioners, a factor is used to estimate the fuel emissions. Individual grid emission factors were obtained from the Institute for Global Environmental Strategies, 2023, the UNFCCC, 2022 and the National and European Emission Factors for Electricity Consumption, 2020. Gaps in the data and discrepancies between data sets have been corrected using averages or data for countries similar in size and GDP. In addition, Minimum Energy Performance Standards (MEPS) and labelling schemes are used to estimate the energy efficiency categories for which energy consumption is calculated. These categories and the share of equipment in each of them is uniform within a CG. Except for unitary AC, where data was gathered for the countries where available values were found. These countries are: Australia, Bahrain, Bangladesh, Benin, Brazil, Burkina Faso, Cape Verde, China, Cote D’Ivoire, Cuba, Ecuador, Egypt, El Salvador, EU, Gambia, Ghana, Guinea, Guinea Bissau, Hong Kong, India, Indonesia, Kenya, Liberia, Malaysia, Mali, Mexico, Morocco, Nicaragua, Nigeria, Pakistan, Philippines, Qatar, Russia, Saudi, Arabia, Senegal, Sierra Leone, South Africa, Thailand, Togo, Tunisia and the UAE.

The data was obtained from the International Energy Agency (IEA) and CLASP. However, direct sources to the legislation in some of the countries were consulted for more specific information. In order to assess the impact of mitigation strategies three different scenarios were calculated: a business-as-usual (BAU) scenario, a mitigation (MIT) scenario which considers refrigerant and system design changes and improvements in the energy efficiency and a Kigali Implementation Plan (KIP) scenario which takes into account the HFC reduction targets set by the Kigali Amendment for the transition to low GWP refrigerants.  A comparison between the BAU scenario and the MIT and KIP scenarios results in the mitigation potentials.
Calculations were done separately for developed and developing countries as the type of equipment, energy efficiency and refrigerants differ substantially.

A full description of this vintage bottom-up stock model can be found in module 1 of the GIZ technical handbook on NAMAs in the RAC&F sectors (GIZ 2013).

Recent updates

  1. Six country-level Tier 2 inventories from Article 5 countries were included into the website. The inventories were the result of field data collection, modelling and validation of the results by government institutions or stakeholders. The countries for which inventory data has been added are Colombia, Costa Rica, Ghana, Mauritius, Philippines and Vietnam.
  2. A new sector consisting of heat pumps was added for CG3 countries only. Sales data from the European Heat Pump Association (EHPA) were used to estimate the direct and indirect emissions of heat pumps in the EU. This sector was divided into three sub-sectors according to their purpose:
  • Space Heating/Cooling HP consist of heating only HP (air/water), heating only HP (brine/water), heating only HP (direct expansion/water), heating only HP (water/water), heating only HP (others), reversible HP (air/air), reversible HP (air/water), reversible HP (brine/water), thermally driven HP and hybrid HP.
  • Sanitary Hot Water HP consists of exhaust air HP air/air, exhaust air HP (air/water), sanitary hot water HP (water heaters) and sanitary hot water HP (exhaust air).
  • Commercial and Industrial HP consists of industrial HP (air source), industrial HP (ground source), industrial HP (water source), reversible HP (VRF) and district heating.

The EHPA Market Assessment report includes sales figures from 21 European countries for the years 2018-2022, as well as combined sales and inventory data for the years 2005-2022. The sales figures for each country are further broken down by appliance type. These datasets were used to calculate the sales of each appliance category from 2005 to 2022. In addition, heat pump stocks projections were used to forecast sales and stocks for each unit type. The data was then consolidated for each subsector. For countries without data, sales per capita from an EU country with a comparable GDP and climate were used as a reference to estimate total sales. Additional parameters for the calculations were obtained from ATMOsphere, 2022; BAFA, 2023; EHPA, 2023; Péan et al., 2022 and Spoelstra, 2014.


  • ATMOsphere. (2022). Accelerating the EU’s shift towards natural refrigerant domestic heat pumps.
  • BAFA. (2023). Liste der förderfähigen Wärmepumpen mit Prüf-/Effizienznachweis: Bundesförderung für effiziente Gebäude-Einzelmaßnahmen (BEG EM) Zuschuss.
  • EHPA. (2023). European Heat Pump Market and Statistics Report 2023.
  • GIZ 2013. NAMAs in the refrigeration, air conditioning and foam sectors.
  • Institute for Global Environmental Strategies (2023). List of Grid Emission Factors, version 11.1. Available at:
  • McNeil, M. A., & Letschert, V. E. (2008). Global Potential of Energy Efficiency Standards and Labeling Programs (November).
  • McNeil, M., & Letschert, V. (2008). Future Air Conditioning Energy Consumption in Developing Countries and what can be done about it: The Potential of Efficiency in the Residential Sector.
  • National and European Emission Factors for Electricity Consumption (NEEFE), JRC-COM-NEEFE_1990-2020
  • Péan, T., Romaní, J., Fuentes, E., & Salom, J. (2022). Seasonal performance and potential of heat pumps in Catalonia. Building Simulation Conference Proceedings, 269–276.
  • Spoelstra, S. (2014). Industrial Heat Pumps.
  • Schwarz, W., Gschrey, B., Leisewitz, A., Herold, A., Gores, S., Papst, I., Usinger, J., 2011. Preparatory story for a review of Regulation (EC) No 842/2006 on certain fluorinated greenhouse gases. Final, 340.
  • UNFCCC, Default Grid Emission Factor Dataset Version 01.1 Date: January 2022.

MEPS databases: