split system

Flammable future for split systems?

German development agency GIZ has published a resource guide promoting the use of R290 (propane) in split system air conditioners.

The guide highlights the efficiency benefits and potential emissions reductions that propane offers, and addresses concerns about flammable refrigerants. Ultimately, it aims to encourage policy-makers to facilitate the market uptake of energy-efficient split systems using R290.

Split systems are the most commonly used appliance for space cooling worldwide, and the global stock is growing fast. The International Energy Agency estimates that by 2050 the number of split systems will increase from just over 850 million to over 3.7 billion.

Propane potential

After carrying out market assessments in various countries, GIZ found that transitioning split systems to propane would significantly reduce energy consumption and greenhouse gas emissions. It estimates that a market share of 50 per cent by 2050 could cut down total greenhouse gas emissions – directly from refrigerant leaks and indirectly from energy use – by 25 per cent.

“The significant climate impact of room ACs is not only made by fossil fuel-based electricity supply, but also a result of the predominant and massively growing use of halogenated refrigerants such as R22, R410A, and, to a growing extent, R32 with high global warming potential (GWP),” says the German Environment Agency’s Dr Rettina Rechenberg, who wrote the forward to the report.

“For single-split room ACs, the loss of the initial refrigerant charge over the lifetime is 100 per cent or even more, caused through leakages during operation as well as during installation and disposal at the end of life. Therefore, the use of natural refrigerants with very low GWP not only can result in superior energy performance, but also lead to negligible greenhouse gas emissions through refrigerant losses during service and at the end of life.

“This guide clearly shows that single-split room ACs equipped with R290 (propane) exhibit significant environmental advantages through good energy performance and a GWP close to zero. The guide shall contribute to addressing and demystifying all aspects relevant for the successful introduction of R290 split air conditioners.”

Real-world experiences

The information in the guide is based on interviews with industry experts and practical experience gained in GIZ Proklima projects. These include projects in India, Indonesia, Costa Rica, Ghana and the Philippines.

Rechenberg points to the example of India, where domestic manufacturer Godrej & Boyce offers a single-split air conditioner with R290 refrigerant. The product is the most energy-efficient its class and more than 600,000 units have been sold so far with no reported incidents.

“This example should encourage other governments and manufacturers to introduce their R290 solutions to the domestic and worldwide market,” she says. “Considering the phase-down of hydrofluorocarbons such as R410A and R32, R290 is today the only viable and future-proof choice for residential and light commercial single-split air conditioning.”

The ultimate solution?

Despite these grand claims, there are legitimate doubts about whether R290 is the silver bullet for reducing emissions from split systems.

Apart from the obvious concerns around using an A3, highly flammable refrigerant – especially in countries such as the US where regulations are notoriously tight – it is not clear that R290 offers significant performance benefits over synthetic refrigerants such as R32.

Tests conducted by the National Institute of Standards and Technology on optimised systems showed comparable coefficient of performance for R32 and R290. This modest improvement may not convince manufacturers to switch over, especially when balanced against higher manufacturing costs and potential safety issues.

GIZ’s guide also indicates that the use of a flammable refrigerant would limit the size of split systems. According to the guide, a 5kW wall split installed at a height of 1.8m with 500g of R290 cannot be installed in a room with a floor area of less than 44m2.

There is, however, continuing work at international standards level and various test labs to increasing the charge limits for A3 class refrigerants with other mitigation measures in place (e.g., limiting the releasable charge).

At this point, the future for propane split systems remains unclear.

Read the report.

One Reply to “Flammable future for split systems?

  1. A big hullo to the rest of the HVACR world from down under in Western Australia.
    We operate a full service of design and consulting , sales, installation , service and preventative maintenance in all facets of our wonderful industry.
    We have used hydrocarbon refrigerants for the past 27 years, over a quarter of a century In a very broad spectrum of applications.
    Not one incident of any kind, repeat not ONE INCIDENT OF ANY KIND IN 27 YEARS..
    We have over the past 10 years trained many technicians how to achieve the best energy, safety and reliability and longevity results using hydrocarbon blends of refrigerants supplied by Engas pty ltd , a home grown WA supplier of extremely well blended all round refrigerants .
    There have been thousands of R410A split systems converted to the HC M60 refrigerant over the last 10 years with an average energy saving of 34% some makes even pull 46%.less amps, all systems also exhibit a better delta T by between 2 and 5 deg c. Resulting in real increased heat rejection figures that leave all other refrigerants in the dark ages.
    We have also been using M20 Engas product as the replacement for the very energy inefficient,toxic, high GWP of 2330 R32 refrigerant. In case your wondering why I’ve rated R32 with a GWP of 2330, I haven’t, thats the rating ASHRAE released for the first twenty years and 675 for a hundred years but as the R32 has a shelf Life of only 21.6 years once released to atmosphere then I believe with good reason that its absolute none sense to promote it in any other category than the twenty year rating.
    We achieve a mind blowing 56% drop in running amps when retrofitting these R32 systems with Engas M20 And a further staggering 5 to 6 deg c better delta T.
    We are installing hydrocarbon systems everyday and have been for 10 or so years in the split world.
    Flammable future for split systems ? As per the heading of this release.
    Boom, bang,toxicity, trail of death and destruction for all to see on Utube R32 explosions,, deadly auto ignition characteristics causing devastating detonation pressure waves 10 times the power of an explosion event.
    Hydrocarbon refrigerants do not can not will not ever detonate with auto ignition.
    The safe flammable future has been with us for many years it has been the here and now for a long tine and is sweeping the world and one thing all readers can bet london to a brick on and that is if the big synthetic hitters could patent HC refrigerants in their pure form there would not be one ounce, gram of synthetic refrigerant to be found.

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