VATIS UPDATE Article

Montreal Protocol’s Technology and Economic Assessment Panel (TEAP) presented report of Information on Alternatives to Ozone Depleting Substances (ODSs) during the 37th Meeting of the Open Ended Working Group (OEWG) of the Parties to the Montreal Protocol held from 4th to 8th April, 2016 at Geneva, Switzerland

During the 37th meeting of the OEWG, the TEAP of the Montreal Protocol provided an update on new refrigerant alternatives, information on research studies on alternatives for use under High Ambient Temperature (HAT) conditions and the extension of the mitigation scenarios from the decision XXVI/9 of the 26th Meeting of the Parties (MOP) report to 2050. The salient features of the report are as follows:

a)   Data for business-as-usual and mitigation scenarios are available for the RAC sector, but limited for other sectors.

b)   Out of the 80 fluids which have either been proposed or are being tested in industry programmes, or are pending publication, or have been published in ISO 817 and ASHRAE 34 refrigerant standards since the 2014 RTOC Assessment Report, 15 fluids have been considered by the TEAP for this report and it found that majority of these are new mixtures, but traditional fluids and two new molecules are also included.

c)   There are alternative refrigerants available today with negligible ODP and lower GWP, however, for some applications it can be challenging to reach the same lifetime cost level of the conventional systems while keeping the same performance and size.

d)   Market dynamics are critical in the rate of adoption of new refrigerants. There is a limit to the number of different refrigerants that a market (customers, sales channels, service companies) can manage. Hence, companies will be selective about where they launch a product, avoiding areas which are saturated, and promoting sales where they see the greatest market potential.

e)   It is difficult to assign energy efficiency to a refrigerant, because energy efficiency of refrigeration systems is in addition to the refrigerant choice and further related to system configuration and component efficiencies. In practice the achievable energy efficiency is limited by the cost of the system, as the success in the market depends on a cost-performance trade-off.

f)   The difficulties in assessing the total warming impact related to refrigerants is discussed, including the difficulty of defining low global warming potential and assessing the energy efficiency related to the use of a refrigerant.

g)   Total climate impact related to refrigerants consists of direct and indirect contributions. The definition of the qualifiers “high”, “medium” and “low” in relation to GWP is a qualitative, non-technical choice related to what is acceptable in specific applications. The indirect contribution accounts for the kg CO2-equivalent emissions generated during the production of the energy consumed by the refrigeration, air- conditioning, and heat pump (RAC&HP) equipment, its operating characteristics, which includes the emissions factor of the local electricity production.

h)   Results from the three projects, PRAHA, AREP-II, and ORNL, indicate a way forward in the search for efficient low-GWP alternatives for high ambient temperature conditions especially when coupled with a full system redesign.

i)   Further improvements are likely through optimizing heat exchangers circuitry for heat transfer properties and proper compressor sizing and selection.

j)   Full redesign of systems, including new components, will likely be needed to realise systems, using new alternative refrigerants, to match the performance of existing systems in both capacity as well as energy efficiency.

k)   While the commercialization process of refrigerants can take up to ten years, the commercialization of products using these alternatives will take further time.

l)   In HAT conditions, the cooling load of a conditioned space can be up to three times that for moderate climates. Due to the requirements for charge limitation according to certain safety standards, the possible product portfolio suitable for HAT conditions is more limited than for average climate conditions when using the same safety standards.

m)   Although risk assessment work on flammable refrigerants is an on-going research in some countries, there is a need for a comprehensive risk assessment for A2L & A3 alternatives at installation, servicing and decommissioning at HAT conditions.

The Co-Chairs of TEAP said that a second report would be produced for the 38th meeting of the OEWG, covering the other issues listed in decision XXVII/4 of the 27th MOP, and a third update report would be produced for the 28th MOP, which would take into account the discussions at the 37th and 38th meetings of the OEWG, and based on additional information available to the task force of the TEAP.