Kühlgas

Kühlgas is a broad term for gases that are used in cooling systems to absorb heat or to provide low temperatures. In practice it covers refrigerants in air conditioning, refrigeration and heat pumps, as well as gases used for cryogenic cooling in industry. Many Kühlgase operate in closed cycles where the working fluid undergoes phase changes or pressure and temperature changes to transport heat.

Common Kühlgase are fluorinated refrigerants such as R134a (HFC), R410A (HFC blend), and newer low-GWP substances like R1234yf (HFO). CO2 (R744) is used in transcritical cycles; ammonia (R717) is used in large industrial plants; hydrocarbon refrigerants such as propane (R290) and isobutane (R600a) are used in small appliances but are flammable. For cryogenic and specialized cooling, inert gases such as helium, nitrogen, and argon are used to achieve very low temperatures or to purge systems.

Environment and safety: Many refrigerants have global warming potential or ozone depletion potential; toxicity and flammability vary. Regulations such as the EU F-Gas Regulation restrict emissions and steer the transition to lower-GWP or natural refrigerants.

Outlook: The industry trends toward natural refrigerants where feasible, improved system efficiency, better recovery and reuse, and tighter leak prevention. The term Kühlgas is often used interchangeably with Kältemittel in everyday language, though technically they cover a broader range of cooling media.