S R C C Alternatives to H F s in the efrigeration and Air Conditioning Sector ection 01 23 schemes that reprocess significant volumes. As the average recovery rate in Article 5 countries is currently low the relative impact of direct emissions is high. With a strong focus on the introduction of good practice, the relative impact of GWP is expected to decrease although energy consumption also decreases with improved service practice. If a low-GWP refrigerant can be used safely at the same or lower energy consumption level with an acceptable investment, this will obviously be the solution with the lowest TEWI. Energy efficiency is becoming more and more the focus when selecting refrigerants but it is important to realise that efficiency is only, to a small part, a result of the refrigerant selection. Typically the different refrigerants’ theoretical impact on the total performance varies within a few percent, whereas the difference between various technical solutions of equipment design with a given refrigerant can be 20-30% or more. The solution that is 20% better in one application can also be significantly worse at other operating conditions. Simplified generalisations of performance that is not specifically referring to a specific application should be viewed with scepticism. “If it sounds too good to be true, it probably isn’t”. In the technical sections and case studies below, a number of technical and commercial aspects to be considered will be covered. In many countries there is a need to establish or increase local capacity to evaluate the suitability of different alternatives and to implement them in different systems. It is important to evaluate not only the lowest investment options but also the energy efficiency and cost effectiveness of the different options. Therefore, it is easy to conclude that the ideal “one-size-fits-all” refrigerant does not exist and that some refrigerants will be more suitable in some applications than others. All refrigerants have their advocates on the market and there are interest groups promoting the different technologies. It is important that the refrigeration and air conditioning sector and equipment owners do a proper evaluation of the total environmental impact of using different alternatives. Any attempt to come up with one solution for all applications will with almost certainly not be the most environmental nor the most cost-effective option. The opportunity to make improvements to the system in terms of efficiency when they are replaced or retrofitted Th ere are four main routes to replacing HCFCs in the RAC sector 1 Ammonia NH3 (R-717) 2 Hydrocarbons Isobutane (R-600a), propane (R-290), propylene (R-1270), blends, etc. 3 Carbon dioxide CO2 (R-744) 4 Hydrofluorocarbons HFCs (i.e. R-134a and blends such as R-407C, R-410A)should not be neglected. The pay off time for such improvements is often short when done in connection with other work on the plant. Ensuring a proper commissioning and adjustment of controls can often in itself save a significant amount of energy. Due to the phase-out of R-134a in the automotive air conditioning sector, a new low-GWP HFC alternative named HFO-1234yf has been developed by DuPont and Honeywell. At this stage it is not clear if the automotive industry will go this way or move to CO2. As of March 2010 several HFO (hydrofluoroolefine) components are also being considered/studied for RAC applications. There is no sufficient information available to date whether HFO1234yf, by itself or in mixtures with other refrigerants, is a good solution for the RAC sector or if and when it will be commercially available. If the automotive industry takes this route it will require large amount and production capacity: It will take time to establish this to satisfy MAC demand increasing from 2011 as the quantities required in this sector are significant. Introducing additional products in the stationary sector will not be the highest priority in that scenario. It can be expected that the development work in the RAC sector, if it takes place, will require several years of additional research and development. The interest on the market will be dependent on how cost effectively these substances are in design of highly efficient equipment.