Natural refrigerants are the green alternative to freon and have very low environmental impact with minimum values of ODP (Ozone Depletion Potential) and GWP (Global Warming Potential) they respect the ozone layer and the contribution to global warming is below the limits laid down by the Kyoto protocol.

Natural refrigerants, being natural gases, fall within the broader know-how of SOL, which specialises in handling gases at high pressure that may also be toxic or inflammable.

Natural refrigerants are divided into three families:

Ammonia (R717)

Ammonia is a natural refrigerant, known for its very high performance in refrigeration cycles. It has been used in the refrigeration industry since the 1930s, it has a very low boiling point and a high energy efficiency, thanks mainly to a very high latent heat of evaporation.

In contrast to its excellent refrigerant properties, ammonia is toxic for man and inflammable, and not compatible with copper circuits. To get around these problems plant with secondary fluid are used, thus avoiding direct expansion, in association with glycol water or carbon dioxide. The complexity of these plants means ammonia is used in large industrial plants or in supermarkets and sports structures.

Carbon dioxide R744

Carbon dioxide is the reference for calculating GWP and so is extremely respectful of the environment in terms of global warming and has no impact on the ozone layer, in the past it was extensively used until the arrival of CFCs and HCFCs (which today can no longer be used).

The characteristics of carbon dioxide, in addition to good heat transmission, are high volumetric cooling capacity, which makes it possible to use small volume compressors, and excellent thermodynamic efficiency at low and medium temperatures. The peculiarity of carbon dioxide compared with other refrigerants is that specially designed plants are necessary to cope with its state diagram (P/T).

It is neither toxic nor inflammable, is not covered by patent and there are no limitations on its use worldwide, factors that make the costs of production and distribution low compared with other refrigerant gases.

Hydrocarbons 

Like ammonia, hydrocarbons were widespread until the arrival of CFCs and HCFCs, both in the home and industrial environments. Today they have become very interesting once again since, as they do not contain either fluorine or chlorine, they respect the environment: almost all home fridges currently on the market use hydrocarbons.

The use of hydrocarbons for refrigeration has the big advantage, in addition to its excellent heat transporting properties, of making it possible to use mineral oils, and so avoid the problems of humidity linked to the use of synthetic lubricants.

The danger of plants using hydrocarbons today is very low, thanks to the reduced quantity of HC present in the devices and the provisions of regulation EN378.

Application table