Long-term available refrigerants
Refrigerants that shall be available in large amounts for widely used applications will have to fit into a sustainable economic system and have an environmental impact as low as possible. Especially in the EU, the development is in this direction.
From today's view this could mean:
- ozone depletion potential ODP = 0
- very low global warming potential GWP <10
- high energy efficiency
- very low to no amount of breakdown products harmful to the environment
- very low production effort
- very little production waste generation
Depending on the application, these criteria are met by a series of naturally appearing substances:
- R717 ammonia
- R744 carbon dioxide
- R718 water
- R729 air
- R290 propane
- R1270 propene
- R600a isobutane
- R600 butane
- and some more hydrocarbons
These substances are on top of a wish list of the German Federal Ministry for the Environment from the early 1990s, even though some of them are synthesized or cleaned and processed with some effort. In this list, partly fluorinated substances were considered transitional refrigerants only.
Some other, also partly fluorinated refrigerants, might be available in certain amounts, probably also depending on other regulations (Regulations and other legal provisions). The amount and time of availability will be determined by national and regional regulations. The EU is expected to reduce availability fastest.
As refrigeration, including air conditioning, heat pumps, process cooling and many special applications, is covering a wide working area, it is also necessary in future to have many different refrigerants available, to operate efficiently. The majority of applications, however, will be based on the list above.
As it is expected today that the number of refrigerants available to select from will decrease, the industry will have to work on solving the tasks with the available materials. Within this view, it might be necessary to reconsider some of today's no-gos, like flammability class A3, operation below ambient pressure, investing in larger pipe diameters.