Rtoc assessment Report 2014 (Slight corrections made in Tables 2-8 and 2-9)

Water heating heat pumps

Current status
Air-to-water and water-to-water heat pumps have experienced significant growth in Japan, Australia, China, and Europe during the last ten years. HCFC-22 is still used in some Article 5 countries. The HFC blends R-410A and R-407C are currently used in Europe and other countries. R-744 heat pump water heaters were introduced to the market in Japan in 2001 and have seen a steady growth since then due to strong government support. In the past, the number of HC-290 applications in Europe has decreased, due to the Pressure Equipment Directive, however, recently a range of HC-290 compressors have become available. R-717 is mainly used for large capacity heat pump systems.

What is left to be achieved

Based on regulations in Europe, the water heating heat pump industry is looking to alternatives with a lower GWP than the one for R-410A.

The main challenge is to come with an efficient, cost effective, safe and easy to use solution. It is expected that other regions will follow the tendency to reduce the GWP value of refrigerants.

The way forward

For water heating heat pumps, HFC-32 or blends with unsaturated HFCs will be studied for future use by taking into account the performance, costs and the necessary safety regulations in relation to their lower flammability. R-744 systems will be optimised and used wherever possible, taking into account costs that will apply. HC-290 and R-600a will be used where possible, taking into account the costs involved and safety in regards to flammability.

Chillers

Current status

The phase-out of ozone-depleting refrigerants in chillers is moving along well. The CFCs have been essentially phased out for new equipment and the CFC banks are decreasing in existing chillers. The current generation of chillers using zero-ODP refrigerants had been introduced without a sacrifice in reliability or energy efficiency. HC-290, R-717 and R-744 are also being used in chillers. Water as a refrigerant is currently being used in absorption chillers and had been recently announced in vapour compression based chillers. The use of HCFC-22 in new equipment has been phased out in developed countries; many Article 5 countries also have stopped its use in new equipment. Limits set for HCFC-22 production and its rising costs have contributed to the conversion of new and existing chillers to zero ODP refrigerants.

What is left to be achieved?

The energy consumption of chillers dominates their environmental impact because the latest generation of chillers has low leak rates and, therefore, low direct global warming impact. The issue, then, is to determine which of the new refrigerants has high energy efficiency in chillers while being safe to use and having acceptable application costs. Major efforts have been launched to propose and test new lower-GWP refrigerants to replace the higher-GWP refrigerants currently in use.

The way forward

Testing of new, lower GWP refrigerants started several years ago and is continuing. At this juncture it is not clear which refrigerants may be selected for commercialisation. Tradeoffs are apparent among GWP, energy efficiency, safety, and applied cost. Refrigerants that are non-flammable with the A1 refrigerant safety classification generally have GWPs of 600 or more. Refrigerants with low GWP (<150) generally are flammable. All flammable refrigerants require special safety considerations. A2L refrigerants will not be widely used without changes to safety standards and building codes.

Vehicle air conditioning

Current status
Today the overwhelming majority of new AC equipped passenger cars world-wide use HFC-134a. The transition from CFC-12 is complete for new systems, but there are still cars in use especially in Article 5 countries. In order to meet the EU MAC Directive and to harvest potential US EPA CO2 credits, OEMs evaluated several refrigerant options for new car (and truck) air conditioning systems. As a result, some car manufacturers have started to equip certain models with HFC-1234yf. Owing to safety concerns regarding the A2L-refrigerant HFC-1234yf, other car manufacturers work on R-744 systems in order to introduce them into the market by the year 2017. Both options have GWPs enabling the GHG credits in US, they are below the EU threshold of 150 and both can achieve fuel efficiency comparable to the existing HFC-134a systems with appropriate hardware and control development. Also owing to safety concerns the use of hydrocarbons or blends of hydrocarbons has not received support from vehicle manufacturers. Most new bus or train air conditioning systems are currently equipped with the refrigerants HFC-134a or R-407C; fleet tests of R-744 systems in buses are on-going.

What is left to be achieved

At the end of 2014 it looks likely that more than one refrigerant will be used in the coming years for car and light truck air conditioning. HFC-134a will remain largely adopted worldwide, HFC-1234yf will continue its growth in new models at least in the near future, other new low GWP synthetic refrigerants or refrigerant blends (e.g. R-445A) may be implemented, and R-744 is expected to be implemented by German OEMs starting in 2017.

The way forward

Along with the Global Warming Potential issue the future spreading of the two refrigerants HFC-1234yf and R-744 in the worldwide vehicle air conditioning market will be significantly governed by additional considerations like safety, costs, regulatory approval, system reliability, heat pump capability (especially for electric driven vehicles) and servicing. At the moment, it cannot be foreseen whether or not the old and the new refrigerants will see parallel use in the market for a long period of time. Without existing regulations it is also unclear whether the bus and train sector will follow these trends.