Luonnonkylmäaineiden

Luonnonkylmäaineet, or natural refrigerants, are substances found in nature that can be used to transfer heat in refrigeration and air conditioning systems. Unlike synthetic refrigerants that are manufactured chemically, natural refrigerants have a lower environmental impact, particularly regarding their ozone depletion potential (ODP) and global warming potential (GWP). Common examples include ammonia (NH3), carbon dioxide (CO2), and hydrocarbons like propane (R290) and isobutane (R600a).

Ammonia is a highly efficient refrigerant with zero ODP and GWP. However, it is toxic and flammable, requiring stringent safety measures in its application, primarily in industrial refrigeration. Carbon dioxide, another natural refrigerant, has a GWP of 1 and zero ODP. It operates at higher pressures than many synthetic refrigerants, necessitating specialized equipment. CO2 is increasingly used in commercial refrigeration, particularly in supermarkets.

Hydrocarbons, such as propane and isobutane, have very low GWPs and zero ODP. They are highly flammable, which limits their use in larger systems, but they are becoming more popular in domestic refrigerators and smaller air conditioning units due to their excellent thermodynamic properties and environmental benefits. The transition to natural refrigerants is driven by international regulations aimed at phasing out substances that harm the ozone layer and contribute to climate change. While they offer significant environmental advantages, their implementation often requires system redesigns and careful consideration of safety aspects.