6. Outlook

In conjunction with GHG emissions reduction targets (a minimum target of – 50% is regularly mentioned for 2050), in order to limit global warming to around 2 K, the following developments seem unavoidable, pending new developments not yet known:

• the development of ammonia use thanks to recent regulatory relaxations and load reduction solutions;

• developing the use of CO ₂ :

  • cascade associated with ammonia,

  • for high-temperature heat pumps and domestic hot water (DHW) systems,

  • in compact transcritical systems ;

• the use of new exchangers such as microchannels to reduce refrigerant charges;

• ...