Changing over to natural refrigerants

By Sabine Lobnig, Feb 11, 2009, 13:15 4 minute reading

Monika Witt, chair woman of eurammon - the European initiative for natural refrigerants - talks about the HCFC phase-out, its impact on the industry and the use of natural refrigerants instead.

As from 2010, only reconditioned HCFCs may be used throughout the EU, followed five years later by a ban on all HCFCs without exception. Are the refrigerating/AC industries ready for this?

Witt: The industry is prepared and in a position to offer tailor-made substitutes, but many customers are still waiting to see what is going to happen and postponing the issue.

To what extent will the industry be affected by the phase-out?

Witt: Industrial refrigeration has always given preference to natural refrigerants, already on account of their energy efficiency: ammonia is acknowledged to be the most efficient refrigerant of all. But there are also various industrial refrigeration systems which still run on HCFCs. This applies to France in particular. Similarly, synthetic refrigerants are still frequently used in commercial refrigeration.

Which alternatives are available to refrigeration system engineers, operators and planners?

Witt: There's no general answer to this one: the right system concept has to be developed individually in each particular case. Certainly, ammonia, carbon dioxide and hydrocarbons offer the best alternatives in many cases.

What is going to happen to the supply and price of recycled HCFCs?

Witt: We don't expect there to be a great supply of recycled HCFCs, on account of the well-known high leakage rates from HCFC systems. The price is therefore expected to be on a fairly high level.

When refrigeration engineers and users opt for HFCs, what do they have to bear in mind?

The refrigeration system has to have a particularly leak-proof design on account of the high global warming potential (GWP). In addition, it is very difficult to locate leaks. Recurring inspections are therefore prescribed by law, to take place every six or twelve months depending on the size of the system. In addition, precise records have to be kept of replenished quantities of refrigerant.

However, a ban on HFCs must be expected in the long term. The chemical industry is already researching into substitute refrigerants, but these bring their own problems. Furthermore, refrigerant 1234yf which is currently undergoing development is far more expensive than natural refrigerants.

Why is it worth changing over to natural refrigerants?

Natural refrigerants are the right choice for anyone looking for a sustainable, energy-efficient refrigerating system. Ammonia, carbon dioxide and hydrocarbons protect both the earth's atmosphere from overheating and the ozone layer. Natural refrigerants are efficient and keep operating costs down. In addition, they are low in price and available in large quantities. Natural refrigerants can be disposed of easily at the end of a system's life cycle.

Can natural refrigerants be used for all HCFC applications?

There are solutions with natural refrigerants for practically every application. The important thing is that the refrigerating system engineers, operators and planners are openly in favour.

Can HCFC systems be converted to natural refrigerants?

Conversion is usually difficult, as either the materials used in the system are not suitable (e.g. copper is not suitable for ammonia) or the necessary pressures are higher than in the existing system (e.g. a system running on carbon dioxide is normally rated for 40 bar). Which is why natural refrigerants normally lend themselves primarily to new systems. But conversion is also possible in individual cases.

Which natural refrigerant is best suited to which application?

Carbon dioxide is often a good choice for low temperatures, while ammonia is ideal particularly for industrial purposes above -35°C. Propane is popular in the chemical industry and suitable for use at moderate temperatures. In addition, blends such as azeotrope R723 can be used: this consists of ammonia and dimethyl ether and is also permitted in our latitudes for example when using air-cooled condensers.

Which regulations have to be heeded when using natural refrigerants?

DIN EN 378 "Refrigerating systems and heat pumps – Safety and environmental requirements" applies in equal measure to all refrigerating systems in Europe. Over and beyond this, the operation of refrigeration systems is also subject to various regionally differing regulations. eurammon is therefore campaigning in Brussels to get these regulations harmonized within the EU.

What is going to happen with HCFC refrigerants after 2015?

Practice has shown that leakage rates from refrigeration systems with odourless refrigerants are clearly higher than the estimated 1 to 3%. If the systems are not designed to be more leak-proof, we can already expect refrigerants with a high GWP value to be banned after 2015. It is up to the politicians to name clear targets. We are sure that it will be possible to provide alternatives to achieve these dates. There is always a way, once the target date has been clearly defined!

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By Sabine Lobnig

Feb 11, 2009, 13:15




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