green cooling initiative: Unitary air conditioning

Unitary air conditioning

The subsector unitary air conditioning (UAC) contains ductless split, ducted split and rooftop ACs as well as variable refrigerant flow (VRF) systems and self-contained units, which are movable ACs and window/through-the-wall units. Typically one unit is installed to cool one room with the exception of VRF systems and multi-splits, both of which can be used for several rooms. In reversible ACs, the cycle can be reversed and used for heating. The most common UACs, split residential ACs consist of two modules, one of which contains the compressor, outdoor heat exchanger and expansion device and is installed outside. The other module with the indoor heat exchanger is placed inside in the room.

Inverter technology is used in many new units as they can help with improving the energy efficiency during part load operation. Inverters enable the control of the compressor speed according to the cooling demand, thereby reducing the so-called cycling losses that are present with on-off control.


SubsectorUnitary air conditioning (UAC)
Typical applicationSplit residential ACs make up 80% of the UAC market in terms of numbers of units. The numbers in this section refer mainly to this type of appliance. Other types of UAC appliances include: moveable ACs, window or through-the-wall ACs, self-contained units, ducted split units, VRF systems, rooftop ACs
Typical end-usersPredominantly households (in some countries also hotels, stores etc.)
Main refrigerants usedHFC-410A, HCFC-22
Natural refrigerant alternativeHC-290 (propane), HC-1270 (propene)
Growth rate / future demandHigh: In Southeast Asia, air-conditioning sales are growing by about 20 % per year. Roughly two-thirds of the global UAC market is located in Asia and SE Asia and the highest growth rates in 2012 were also found in this region. Nonetheless, air conditioner penetration in key markets is still low (e.g., India 4%, Thailand 14%, Indonesia 7%, Vietnam 6%, Philippines 11%). Calculation results show that the number of appliances in use in the top-6 countries, which make up 80% of the global stock, will grow from 600 million currently to nearly 1.6 billion units. Show on world map.

Scope of improvement: direct emissions

  • Switch to natural (hydrocarbon) refrigerants
  • Leakage reduction
  • Reducing end-of-life emissions
  • Reducing overall cooling needs in new building developments

Read more on the scope of improvement: direct emissions

Scope of improvement: energy efficiency

  • Optimise components: compressor (variable speed), heat-exchanger
  • Inverter technology
  • Using hydrocarbon refrigerants
  • Reducing losses in standby or off modes, occupancy sensors
  • Reducing overall cooling needs in new building developments

Read more on the scope of improvement: energy efficiency