At a Glance
Nature as developer
All natural refrigerants occur in nature's materials cycles even without human interference – hence "natural." These are set apart from synthetically produced refrigerants, which fall into two groups: 1) CFCs and HCFCs (chlorofluorocarbons), which have ozone depletion potential, and 2) FCs and HFCs (fluorocarbons), which have zero ozone depletion potential. In addition some of the second group have considerable direct global warming potential (GWP).
By the way: while ammonia is manmade for use in the refrigeration process, it is nonetheless a natural refrigerant, as it also occurs in nature in this form, e.g. in the natural nitrogen cycle or in people's daily perspiration.
An unbeatable climate protector
In the light of global efforts for climate protection, there is a vital interest in natural refrigerants. Because – unlike some synthetic refrigerants – they do not deplete the ozone layer and have a negligible effect on the greenhouse effect, they are unbeatable from a climate point of view. Thanks to their great efficiency, natural refrigerants do not contribute much to the indirect greenhouse effect – a fact that is confirmed in comparative calculations using the TEWI (Total Equivalent Warming Impact) method.
A glance at the figures: economically sustainable
The use of natural refrigerants is also well worth it from an economic viewpoint. The refrigerants themselves are very inexpensive, which has a positive effect not only on the initial filling of a plant, but also, from a leakage point of view, on the operating costs. In addition, natural refrigerants are highly efficient which helps to keep the energy requirement of a plant low. Not only that, its disposal is inexpensive. The assumption that investment costs for plants using natural refrigerants is always 10 to 20 percent higher than for plants using synthetic refrigerants is wrong and must be put into perspective. Depending on the type and size of the system, there may indeed be extra expenses – but by the same token, these may be offset by reduced costs. Meanwhile, the aspect of operating costs is a crucial one – here, plants using natural refrigerants score very well indeed. In efficiency studies spanning several years, they are often several steps ahead of their rivals. Reasons include lower leakage-related costs, the low cost of maintenance, as well as – and this is particularly relevant for industrial plants – their low energy consumption. Add to this the relatively inexpensive disposal of natural refrigerants at the end of a facility's service life.