In preparation for the phase-out of HCFCs, local customers have begun trialling R32, a more environmentally friendly refrigerant that has just arrived on Australian shores.
R32 has a Global Warming Potential (GWP) of 650, which is significantly less than the more commonly used R410A which is 1,980.
Under ASHRAE guidelines it is classified as A2L, or mildly flammable. Generally, the lower the flammability of a refrigerant, the larger its GWP.
But with customers increasingly adopting alternative low GWP refrigerants, the use of flammable refrigerants has risen significantly in recent years.
R32 is considered an ideal alternative because it isn’t too flammable, has low toxicity and has been successfully trialled overseas.
As a result Australia has begun following the lead of other countries that have performed successful tests with R32.
For example, Daikin in Japan began using R32 in all models of its residential air conditioners last year before announcing plans to use the refrigerant in Europe.
Danfoss also announced that its customers are testing R32, R1234yf and R1234ze.
Because thermodynamic properties can have a big impact on system and compressor performance, Danfoss has published comparisons between R32 and R410A on its web site.
Some of the benefits of R32 include: lower refrigerant cost than R410; better performance at higher ambient conditions; similar pressure and pressure ratios; lower system charge requirement and lower mass flow; higher liquid thermal conductivity, higher heat transfer coefficient at same mass flux and; the potential to optimize heat exchanger with smaller tube volume for further charge reduction.
The disadvantages include its A2L mild flammability rating, higher compressor discharge temperature from higher vapor specific heat and new oil is required since existing polyolester (POE) oil is not miscible with R32.
The vice president of engineering services and sustainability at Emerson Climate Technologies, Rajan Rajendran, said that based on efficiency and cost R32 is an attractive alternative.
“R32 can serve as the initial candidate for new equipment to meet any potential HFC phase down proposal for at least until the year 2020,” he said.
In preparation for the arrival of R32 the Australian Refrigeration Council (ARC) issued an advisory to technicians in its CoolChange Newsletter.
It referred technicians to the Flammable Refrigerants Safety Guide released by the Australian Institute of Refrigeration, Air Conditioning and Heating (AIRAH). The guide is available for download from the “technical resources” section of www.airah.org.au
For training in low GWP refrigerants, technicians should go to www.ee-oz.com.au or contact www.ausref.org.au/training.