jäähdytysaineissa

Jäähdytysaineissa, known in English as refrigerants, are substances used in refrigeration and air conditioning systems to absorb heat from a low-temperature reservoir and release it to a higher-temperature reservoir. They undergo a phase change, typically from liquid to gas and back to liquid, during the refrigeration cycle. This phase change is crucial for their heat-transferring properties.

Historically, various compounds have been used as refrigerants. Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) were widely adopted due to their excellent thermodynamic properties and non-flammability. However, their significant ozone depletion potential (ODP) led to their phase-out under international agreements like the Montreal Protocol.

Hydrofluorocarbons (HFCs) were introduced as replacements for CFCs and HCFCs. While they do not deplete the ozone layer, many HFCs have a high global warming potential (GWP), contributing to climate change. Consequently, regulations are now targeting the reduction and eventual phase-down of high-GWP HFCs.

Current research and development focus on refrigerants with low GWP and ODP, often categorized as natural refrigerants or hydrofluoroolefins (HFOs). Natural refrigerants include substances like ammonia, carbon dioxide, and hydrocarbons. These often have excellent environmental profiles but may present challenges related to toxicity, flammability, or operating pressures, requiring specific safety measures and system designs. HFOs are synthetic compounds with significantly lower GWPs compared to HFCs, offering a promising alternative for many applications. The selection of a refrigerant depends on factors such as the specific application, desired temperature range, efficiency requirements, safety considerations, and environmental regulations.