Air-conditioning

Stationary air conditioning is categorised into the following main classes used in the EU:

  • Factory sealed (moveable)
  • Split system sector
  • Multi-split systems including VRF systems (Variable Refrigerant Flow)
  • Chillers

Heat pumps are described in a different applications section, although reversible air-conditioning systems combine heating and cooling in the same system. Air-conditioning is used for human comfort (domestic and commercial), in keeping hygienic conditions in hospitals, retirement homes and public buildings and ensuring controlled conditions for sophisticated computer systems.

In domestic dwellings, air-conditioning equipment typically consists of direct units, and may be portable units, or small split units through to multi-split systems for whole dwellings. Many large commercial offices, retail premises and hotels, can have central chillers in plant rooms utilising a secondary chilled water system. Smaller commercial offices and retail buildings can have very sophisticated multi-split systems (VRF) which can provide heating and cooling in different parts of the building, allow for heat recovery, and are very efficient

HFCs are a very efficient and effective option for the diverse range of air-conditioning applications in Europe, with HFC 410A being the most widely used HFC for air-conditioning applications. Chillers, which use a chilled water loop to provide cooling typically use HFC 410A for small chiller systems, but HFC 134a is also used for large centrifugal chillers.

F-Gas Regulation 517/2014 has two use bans that apply to the air-conditioning sector:

  • Movable room air-conditioning equipment (hermetically sealed equipment which is movable between rooms by the end user) that contain HFCs with GWP of 150 or more: 1 January 2020.
  • Single split air-conditioning systems containing less than 3 kg of fluorinated greenhouse gases, that contain, or whose functioning relies upon, fluorinated greenhouse gases with GWP of 750 or more: 1 January 2025.

Lower GWP fluorocarbon refrigerants

Equipment manufacturers and refrigerant producers are developing systems using lower GWP refrigerants. In Japan in 2014 100% of residential split air conditioner production was switched to HFC-32 (class 2L flammability), and this solution is being promoted outside Japan. Many manufacturers are also evaluating new HFC/HFO blends, such as mixtures of various compositions of HFC-32, HFC-125, HFC-134a, HFO-1234yf and HFO-1234ze, which are designed to offer specific properties and performance1.

Flammability and the charge sizes for Multi-split systems including VRF systems (Variable Refrigerant Flow) prevent the use of hydrocarbons in direct systems. [Preparatory study for a review of Regulation (EC) No 842/2006 on certain fluorinated greenhouse gases Annexes to the Final Report September 2011, page 314] HFC 410A is particularly suited this application due to its performance and non-flammability, but applications using lower GWP fluorocarbon refrigerants, including HFC 32 and blends with moderate flammability (class 2L flammability) that have similar characteristics to HFC 410A are being evaluated2

For chillers, in order to be acceptable, new refrigerants should result in products with energy efficiencies that are equal to or better than the refrigerants replaced. The global warming effects from chillers are dominated by the energy-related component from their power consumption. Total Equivalent Warming Impact (TEWI) and Life Cycle Climate Performance (LCCP) models typically show that more than 95% of the climate effect is due to energy consumption. The direct global warming effects from refrigerant emissions are significantly smaller since direct emissions have been significantly reduced in recent years through lower charge systems, low-leak designs, manufacturing and testing improvements, and improved service practices. Chillers have traditionally used an array of refrigerants due to the economics associated with high performance compressors as well as physical size and manufacturing constraints over the range of capacities provided by chillers. After years of research and screening tests, an array of choices is emerging. Some commercialization has started and there are some recent new product introductions using lower GWP fluorocarbon refrigerants3.

1 UNEP June 2016 Report of the Technology and Economic Assessment Panel Volume 1 Progress Report
2 UNEP 2014 Report of the Refrigeration, Air Conditioning and Heat Pumps Technical Options Committee 2014 Assessment
3 UNEP June 2016 Report of the Technology and Economic Assessment Panel Volume 1 Progress Report