COOLING | SHAPE MEMORY ALLOYS conveyor belt with new blends coming online roughly every six months, and were hoping to bring the developmental process in-house in the next few months, says OToole. If we come up with a new blend, because of our commonality of components and modular core, we can swap in a new stack and get the benefit, he says. So, if the stack is more efficient which can come through moving more heat around, or a reduction in the amount of load needed to apply to the material you can swap in that core and start compressing it in the same sequence. Their latest iteration of the nickel titanium blend has a material coefficient of performance (COPmat) of 27-30, says OToole. Its what we do on the microstructure combined with the chemical blend that gives us constant improvements. In the future, more gains will be made with improved material, says OToole. If youre moving more heat around with less energy in, you use less material, which is a direct saving on the amount of SMA that goes in. SMA makes up 30% of production costs of the system so, the less you use, the better, which comes down to more efficient materials. Other parameters such as the heat transfer fluid used and how fast the cycle is operating can also be tweaked to get further performance improvements and cost reductions, says OToole. Moving the current 10-second cycle to a six- or eig ht-second cycle will also have a direct proportional change on the amount of metal in the system because, if you use smaller cores, everything comes down proportionally, bar the controls system, he says. To ensure the performance is high and cost is kept to a minimum, Exergyn is working with a third-party multinational company in the cooling industry (an internet search reveals Carrier). It is expected that the next generation Compressing the material rather than subjecting it to tension has allowed the team to run 70 million cycles, which is equivalent to 40 years of operation in a heat pump of the current 60kW system will be tested at a customers site for the first time. To the future As part of a Disruptive Technologies Innovation Fund grant the company won two years ago, Exergyn is currently working with Dublin City University on a comprehensive life-cycle assessment (LCA) of the technology. At the start, OToole says the LCA is going to be higher because more nickel and titanium is being brought into the market, so there is going to be more mining. But there will come a point where you can start recycling the material because it doesnt evaporate at the end of its life. But we dont know what the end of life is because weve run the equivalent of 40 years and it hasnt failed, he says. The main barrier, says OToole, is not closed-mindedness towards the technology, but that people dont understand it. People have been working with vapour compression for 100 years, and we come and say this lump of metal is going to do that, and do it cheaper. We have to explain how the system works to get people to come round to it, in conjunction with the legislative changes, he says. His vision is that the SMA technology replaces vapour compression systems because I dont see a golden refrigerant at the moment that ticks all the boxes, he says. A GWP of 1 is still infinitely more than zero. Some lower-GWP refrigerants have toxicity and flammability issues, which means more stuff has to go into your system to protect it, says OToole. Being GWP-free and non-leaking, our technology circumvents that. So, by hitting the efficiency and cost and size targets, were hoping to make this a no-brainer retrofittable technology that coincides with the rollout of new [F-gas] regulations, he says. Somethings going to have to change and, if you go to the legislators and present a viable alternative, its possible that this could explode. But not literally, he hastens to add. Its coming to the right time, and we will push that message out there and, if all the stars align, it could revolutionise cooling. CJ The most sustainable Commercial Air Source Heat pump Titan Sky The Superior Natural Choice Air Source Inverter Heat pump Natural refrigerant (R290) Heating Capacity: 30-200 kWMax Hot water production: +63C Minimum Ambient:-20C SCOP: up to 4.12 Lowest Total Equivalent Warming Impact (TEWI) Unbeatable use of Primary energy thanks to Inverter technology No Ozone Layer impact & Nearly Zero Global warming potential Optimized Low Refrigerant Charge design 70 September 2021 www.cibsejournal.com CIBSE Sep 21 pp67-68, 70 Exergyn.indd 70 27/08/2021 13:43